Category Archives: Human Genetics

THOUSAND OAKS, Calif., Jan. 9, 2020 /PRNewswire/ -- Amgen (NASDAQ:AMGN) will present at the38thAnnual J.P.Morgan Healthcare Conference at8:30a.m.PTonTuesday,Jan.14,2020, in San Francisco.Robert A. Bradway,chairmanandchief executive officeratAmgen,will present at the conference.Live audio of the presentation can be accessed from the Events Calendar on Amgen's website,www.amgen.com, under Investors.A replay of the webcast will also be available on Amgen's website forat least90 days following the event.

About AmgenAmgen is committed to unlocking the potential of biology for patients suffering from serious illnesses by discovering, developing, manufacturing and delivering innovative human therapeutics. This approach begins by using tools like advanced human genetics to unravel the complexities of disease and understand the fundamentals of human biology.

Amgen focuses on areas of high unmet medical need and leverages its expertise to strive for solutions that improve health outcomes and dramatically improve people's lives. A biotechnology pioneer since 1980, Amgen has grown to beone ofthe world'sleadingindependent biotechnology companies, has reached millions of patients around the world and is developing a pipeline of medicines with breakaway potential.

For more information, visitwww.amgen.comand follow us onwww.twitter.com/amgen.

CONTACT: Amgen, Thousand OaksJessica Akopyan, 805-447-0974 (media) Trish Hawkins, 805-447-5631(media) Arvind Sood, 805-447-1060 (investors)

Amgen Logo. (PRNewsFoto/Amgen) (PRNewsFoto/)

View original content to download multimedia:http://www.prnewswire.com/news-releases/amgen-to-present-at-the-38th-annual-jp-morgan-healthcare-conference-300984535.html

SOURCE Amgen

Visit link:
Amgen To Present At The 38th Annual J.P. Morgan Healthcare Conference - Yahoo Finance

INTRODUCTION

Congenital defects are a leading cause of morbidity worldwide, accounting for the deaths of 330,000 newborns every year. Brain malformations, including microcephaly and holoprosencephaly (HPE), are the most common congenital anomalies and place a heavy burden on the affected individuals and the health care system (13). HPE is a structural anomaly of the developing forebrain affecting 1:250 embryos and 1:16,000 live-born infants. Clinically, HPE encompasses a continuum of brain malformations and is accompanied with a spectrum of craniofacial defects in 80% of the cases; microcephaly and eye defects are among the most common features in affected individuals (4). In the majority of cases, the underlying cause remains uncertain due to the high complexity and the multigenic origin of these anomalies (5, 6). Lately, it has become clear that HPE is caused by a malfunction in key signaling pathways in the early embryo, leading to developmental defects in the organizing centers and midline structures (7). The defects involve a sequence of developmental steps that begin with Nodal signaling to establish the midline progenitors in the developing primitive streak (PS). It then continues with the proper positioning of the forming prechordal plate beneath the neuroectoderm and activation of midline Hedgehog signals to maintain the anterior identity of the forebrain. However, the restriction of HPE genetic determinants to a handful of NODAL and Sonic hedgehog (SHH) pathway regulators stems from our limited understanding of the molecular events governing specification of early and late midline structures. Expansion of this genetic repertoire has become a necessity to develop therapeutic options and improve molecular diagnosis of HPE.

Genes encoding transcription factors (TFs) and epigenetic regulators are relevant etiological candidates given their central role in integrating signaling cascades and orchestrating multiple biological processes. Deficiency in their function can disturb entire transcriptional programs, involving numerous genes and molecular pathways, leading to a complex pathological outcome. Consistent with this hypothesis, we have recently identified a loss-of-function (LOF) mutation in the transcriptional regulator PRDM15 in patients with a syndromic form of HPE. Here, we combine mouse genetics and epigenomic approaches to uncover the role of this TF in congenital brain malformations. Our findings establish PRDM15 as a key regulator of NOTCH and WNT/PCP pathways in the developing embryo, implicating them in regulation of anterior/posterior (A/P) patterning and forebrain development. In addition, we uncover new genetic variants in key components of these signaling pathways in patients with HPE. Collectively, our findings refine the molecular mechanisms governing forebrain development and set the stage for the identification of new HPE candidate genes.

Homozygosity mapping and whole-exome sequencing on patients with steroid resistant nephrotic syndrome (SRNS) identified three recessive mutations in PRDM15 (NM_001040424.2). These mutations are located in the sequences coding for the PR domain (c.461T>A; p.Met154Lys-M154K and c.568G>A; p.Glu190Lys-E190K) and the 15th zinc finger (c.2531G>A; p.Cys844Tyr-C844Y), respectively (Fig. 1A). Of particular interest, in four consanguineous families that have the variant encoding PRDM15 C844Y, the affected probands exhibited a syndromic form of SRNS consistent with the Galloway-Mowat syndrome (8). Besides renal defects, the patients displayed facial (narrow forehead, microcephaly, abnormal cerebral gyration, and ophthalmic abnormalities) and extracranial defects (heart malformations and postaxial polydactyly) (9).

(A) Schematic representation of the PRDM15 mutation positions and the affected domains. (B) Alkaline phosphatase (AP) staining of ESCs; the respective genotypes are indicated in the lower panel. Data are average of four independent cell cultures (n = 4) SD. Statistical tests were applied on differences observed in the percentage of completely undifferentiated colonies. Students t test (two sided) was used to determine significance. (C) Heat map of differentially expressed genes in ESCs upon the indicated genetic manipulations. (D) mRNA levels of Rspo1 in ESCs; the respective genotypes are indicated by color code. Expression levels were normalized to Ubiquitin (Ubb), and Prdm15fl/fl (empty vector) was used as reference. Data shown are from three independent experiments (n = 3). (E) Enrichment of PRDM15 binding on promoter regions of the target gene (Rspo1) in ESCsrespective genotypes are indicated by color codeas measured by ChIP-qPCR. Depicted is the average enrichment [data from three independent cell cultures (n = 3)] over percent of input. In (B) to (E), the endogenous mouse Prdm15 has been deleted by the addition of OHT (50 nM) after ectopic expression of WT or mutant human PRDM15 (hPR15). In (D) and (E), center values, mean; error bars, SD. Students t test (two sided) was used to determine significance.

We have recently demonstrated that PRDM15 regulates the transcription of Rpso1 and Spry1, two key components of the MAPK (mitogen-activated protein kinase)/ERK (extracellular signalregulated kinase) and WNT pathways, to maintain nave pluripotency of mouse embryonic stem cells (mESCs) (10). To evaluate the effects of these mutations on PRDM15 function, we ectopically expressed the three identified human variants in Prdm15-deficient embryonic stem cells (ESCs) (Prdm15/). Only hPR15-C844Y, which is associated with brain defects in humans, failed to restore ESC self-renewal (Fig. 1B), and most importantly, the global changes in gene expression, induced by loss of endogenous PRDM15 (Fig. 1C and table S1 (A to E)]. These data strongly suggest that hPR15-C844Y is a LOF mutation. While hPR15-M154K and hPR15-E190K rescued Rspo1 expression at levels comparable to the wild-type (WT) human PRDM15 (hPR15-WT), hPR15-C844Y failed to restore its transcript levels [quantitative polymerase chain reaction (qPCR)] and to activate its transcription in a luciferase reporter assay (Fig. 1D and fig. S1A).

To gain further insights into the impact of these mutations on PRDM15 function, we tested the stability of the encoded proteins and their cellular localization. Immunofluorescence staining, in a Prdm15/ background, showed that none of the mutations affected the nuclear localization of PRDM15 (fig. S1B). On the other hand, all three mutants encoded less stable proteins (fig. S1C). We have previously shown that the zinc finger domains are required for DNA binding and transcriptional activity of PRDM15 (10). Thus, we sought to test the ability of the various mutants to bind to chromatin. Consistent with an LOF of the zinc finger mutant, chromatin immunoprecipitation (ChIP)qPCR analysis revealed reduced enrichment of hPR15-C844Y at the promoter region of Rspo1 (Fig. 1E), a result compatible with its inability to promote its transcription (Fig. 1D and fig. S1A).

To gain molecular insights on the effects of PRDM15 LOF during mammalian development, we intercrossed Prdm15lacZ/+ heterozygous mice, which are healthy and fertile. A description of all the Prdm15 alleles and deleter strains used in this study is summarized in fig. S2A. Consistent with a fundamental role of PRDM15 during embryonic development, we obtained no homozygous mutant [Prdm15lazZ/lacZ knockout (KO)] pups (Fig. 2A), while of the hundreds Prdm15lacZ/+ embryos that were dissected at various stages of development, none showed any defects. Timed matings revealed the embryonic lethality of Prdm15lazZ/lacZ (KO) embryos occurs between embryonic days 12.5 (E12.5) and E14.5 (Fig. 2A). Notably, at E12.5, KO embryos were smaller and showed a spectrum of brain malformations affecting predominantly the anteriormost structures of the head, including the eyes (Fig. 2B), consistent with the brain and facial features observed in patients with the C844Y mutation. Coronal sections of the brain at this stage confirmed that the lateral and medial ganglionic eminences were underdeveloped. Furthermore, we noted an abnormal separation of the cerebral hemispheres, reminiscent of HPE (Fig. 2C). Classic HPE encompasses a continuum of brain anomalies caused by neural tube patterning defects that affect the anteriormost structures and is often accompanied by craniofacial defects involving the eyes (4, 11, 12).

(A) Genetic distribution of embryos from Prdm15+/LacZ intercrosses, indicating lethality between E12.5 and E14.5. (B) Phenotypic continuum of brain defects in E12.5 Prdm15lacZ/lacZ KO embryos. (C) Hematoxylin and eosin (H&E) staining of serial coronal sections of E12.5 brains from Prdm15+/+ WT (upper panel) and Prdm15lacZ/lacZ KO (lower panel) embryos. The mutants lack the complex organization of the anterior forebrain, including the lateral (LGE) and medial ganglionic eminences (MGE), the epithalamic and dorsal thalamic neuropeithelium (NE), and eyes. (D) Nestin-Cremeditated deletion of Prdm15 in neuronal precursors does not affect brain development. Representative images are shown in (B) to (D). LGE/MGE, lateral and medial ganglionic eminences; NE, neuropeithelium; NCX, neocortex; E, eye; LV, lateral ventricle; V, ventricle; TOT, total. (B and D) Photo credit: Messerschmidt and Mzoughi.

These results prompted us to delete Prdm15 specifically in the developing brain by crossing Prdm15fl/fl mice to the Nestin-Cre deleter strain. This Cre recombinase is active at ~E11 in neural stem cells/progenitors and would reveal whether PRDM15 is essential for the process of neurogenesis. The resulting Prdm15/::Nestin-CRE embryos did not show any apparent defects at E12.5 (Fig. 2D), were born at the expected Mendelian ratios, and developed into healthy adults (fig. S2B). This suggests that PRDM15 is required at earlier time points of forebrain specification.

Defects in Prdm15 KO embryos are apparent before the onset of neurulation, as mutants were markedly smaller and had an abnormal morphogenesis by E7.5 (fig. S3A). Between E6.5 and E7.5, two signaling centers act sequentially to pattern the forebrain in the mouse embryo (Fig. 3A) [reviewed in (1315)]. The first resides within the extraembryonic lineages and is called the anterior visceral endoderm (AVE). The AVE imparts anterior identity to the underlying epiblast, thereby restricting the site of gastrulationthe PSto the posterior epiblast. During gastrulation, a second specialized population of cells, known as the AME, emerges from the anterior PS (APS). These cells migrate anteriorly, giving rise to the anterior definitive endoderm and prechordal plate mesoderm. Their role is to produce secondary inductive cues that reinforce anterior identity in the overlying neural plate (Fig. 3A).

(A) Schematic of the signaling centers governing A/P patterning in the mouse embryo. (B) At E6.5, Foxa2 is expressed in the AVE (red line) and APS (red asterisk). At E7.5, Lhx1 transcripts label the visceral endoderm (VE) overlying the epiblast including the AVE as well nascent mesoderm and midline axial mesendoderm. In Prdm15 mutants (mut), Foxa2 expression is confined to the distal VE, with little enrichment in the prospective AVE. Lhx1 is detected in the VE and mesoderm of the middle Prdm15 mutant, but only in the VE of the one on the right. (C) Expression of T, Lefty2, Foxa2, Chordin, and Shh in WT and Prdm15lacZ/lacZ embryos at E7.5. In Prdm15 mutants, T is expressed normally in the PS; Lefty2 transcripts are down-regulated in nascent mesoderm; Foxa2 and Chordin expression remains high distally in the region of the APS (angled black-dashed line) but does not extend anteriorly in the midline axial mesendoderm (am); and Shh expression is similarly weak in the anterior midline (asterisk). n, node. (D) Expression of Six3/Shh or Otx2/Shh in WT (upper) and Prdm15lacZ/lacZ KO (lower) embryos at E8.5. Six3 and Otx2 expression highlights the reduction in anterior forebrain (fb) development (angled black dashed lines) in Prdm15lacZ/lacZ KO mutants. no, notochord; mb, midbrain; DVE, Distal Visceral Endoderm. Representative images are shown in (B) to (D). (C and D) Photo credit: Dun and Ong.

We reasoned that loss of PRDM15 might impair forebrain specification during the earliest events of anterior patterning and therefore examined the expression of a panel of marker genes diagnostic for defects in either the AVE or AME in Prdm15 KO embryos. Foxa2 is a marker of both, AVE and APS, in early PS stage embryos at E6.5. In Prdm15 KO embryos, in situ labeling shows expression in the distal visceral endoderm overlying the epiblast in a pattern typically observed 1 day earlier in WT embryos (Fig. 3B) (16). We conclude that Prdm15 KO embryos are developmentally delayed even before gastrulation. At E7.5, Lhx1 is expressed in the nascent mesoderm and anterior midline mesendoderm. In the smaller, delayed Prdm15 KO littermate embryos, Lhx1 is expressed normally throughout the visceral endoderm, including the AVE, as well as in the nascent mesoderm (Fig. 3B) (17, 18). Both FOXA2 and LHX1 are required for the formation and function of the AVE, and their activation provides evidence that the initial specification of the primary anterior-posterior axis by the AVE is normal in Prdm15 KO embryos.

We next examined the expression of PS (T and Lefty2) and AME (Foxa2, Chordin, and Shh) marker genes. By E7.5, Prdm15 KO embryos are easily recognizable due to a characteristic ruffling in the extraembryonic visceral endoderm, with a fully extended PS that expresses both T and Lefty2 (Fig. 3C). At this stage, Foxa2 is expressed in the node, which marks the anterior end of the PS, and the AME that extends rostrally in WT embryos. In contrast, in Prdm15 KO embryos, Foxa2 transcripts are present distally but do not extend anteriorly (Fig. 3C). A similar pattern is observed with Chordin, which also labels the node and AME in WT embryos but is confined to the APS in Prdm15 KOs (Fig. 3C). Shh expression is also diagnostic for the node and AME, but in KO embryos, only a few Shh-positive cells are observed along the anterior midline (Fig. 3C). Together, these results show that loss of PRDM15 specifically affects the production of the anterior AME. Consequently, the crucial refining signals produced by these cells that orchestrate the continued patterning and morphogenesis of the anterior neuroectoderm are lost, resulting in anterior truncations that are evident by diminished forebrain expression of Six3 and Otx2 in Prdm15 KO mutant embryos at E8.5 (Fig. 3D). To further corroborate these findings, we deleted Prdm15 specifically in the epiblast, using the Sox2-Cre transgene (fig. S3B) (19), while maintaining WT extraembryonic tissues. Consistent with an essential role for PRDM15 in the PS-derived AME and not AVE specification, Prdm15/::Sox2-CRE embryos died in utero starting at E12.5 (fig. S3C) and exhibited a spectrum of brain defects similar to those observed in Prdm15 KO embryos (fig. S3D).

To examine the impact of PRDM15 depletion on early embryonic processes, namely, A/P patterning, we sequenced the transcriptome of WT versus Prdm15 KO E6.5 embryos. We reasoned this could be the most critical stage for AME specification as AME cells emerge less than 24 hours later. Unbiased clustering of global gene expression separated WT versus Prdm15 KO embryos into distinct groups, indicating marked transcriptional differences (Fig. 4A and table S1F). Gene ontology (GO) analysis of the significantly down-regulated genes identified Pattern specification process, Head development, and Neural tube development among the enriched terms. Among these genes, several are important regulators of forebrain development and A/P patterning (Fig. 4B and fig. S4A, and table S1, G to H). We noted a striking reduction in the expression of key components of three signaling pathways: WNT, NOTCH, and SHH (Fig. 4C, fig. S4B, and table S1, I and J).

(A) Unbiased clustering heat map of the entire transcriptome in WT (n = 8) versus Prdm15lacz/lacz KO (n = 10) E6.5 embryos, analyzed by RNA sequencing. Heat maps of differentially expressed genes from the indicated GO categories (B) and KEGG pathway (C) identified as top hits in the RNA sequencing. Light and dark blue rectangles on the right side indicate genes whose promoter region is directly bound by PRDM15 in ESCs only or both in ESCs and E6.5 embryos, respectively. (D) Snapshots of representative PRDM15 ChIP tracks (UCSC genome browser). Examples of conserved target genes (binding sites) between E6.5 embryos (blue) and ESCs (orange) are shown.

We have recently shown that PRDM15 recognizes a defined DNA motif present at promoters or enhancers of target genes (10). To define the set of direct PRDM15 transcriptional targets, we performed ChIP sequencing (ChIP-seq) on mESCs and WT E6.5 embryos (table S1, K and L). Despite the limited biological material available from the pre-gastrula embryos, we identified 58 high-confidence promoter-bound targets, the majority of which (~84%) were also bound by PRDM15 in ESCs (Fig. 4D, fig. S4C, and table S1M). In addition, identification of the same PRDM15 consensus binding motif in both systems implies a conservation of its targets. We therefore chose to consider PRDM15-bound promoters identified in ESCs as relevant for our follow-up analyses. Among these, a handful of PRDM15 targets, including Rbpj, Notch3, Maml3 (NOTCH), Vangl2, Wnt5b, Gpc6, Nphp4 (noncanonical WNT), and Gas1 (SHH), were of particular interest as they are significantly down-regulated in the mutant embryos (fig. S4D). Collectively, these data indicate that lack of PRDM15 leads to transcriptional down-regulation of key regulators of developmentally important signaling pathways (NOTCH, noncanonical WNT, and SHH).

These results prompted us to perform a targeted analysis of the down-regulated PRDM15 target genes in a large cohort of patients with HPE (132 trios and 188 singletons). We found heterozygous variants in 99 genes, ~17% of them were likely to be damaging (table S2A). To gain insights on potential functional interactions between these genes, we generated functional protein association networks using STRING. Although the majority of the proteins did not seem to be functionally related, two main networks representing NOTCH and WNT/PCP signaling formed (Fig. 5A and table S2B), supporting their potential involvement in HPE pathobiology.

(A) Functional groups identified by protein association network analysis of PRDM15 target genes mutated in patients with HPE using STRING. (B) mRNA levels of the indicated genes in ESCs; the respective genotypes are indicated in the lower panel. Expression levels were normalized to Ubiquitin (Ubb), and Prdm15fl/fl (empty vector) was used as reference. Rspo1 expression levels were used as positive control in Fig. 1D. Data shown are from three independent experiments (n = 3). (C) Enrichment of PRDM15 binding on promoter regions of the indicated target genes in ESCsrespective genotypes are indicated in the lower panelas measured by ChIP-qPCR. ChIP on the Rspo1 promoter was used as a positive control for PRDM15 binding. Depicted is the average enrichment [data from three independent cell cultures (n = 3)] over percent of input. In (B) and (C), the endogenous mouse Prdm15 has been deleted by the addition of OHT (50 nM) after ectopic expression of WT or mutant human PRDM15. In (B) and (C), center values, mean; error bars, SD. Students t test (two sided) was used to determine significance.

To assess the ability of the PRDM15 mutants to regulate the expression of critical components of both pathways, we took two approaches. First, we performed rescue experiments in Prdm15/ ESCs by reintroducing WT or mutant PRDM15 expression constructs. While hPR15-M154K and hPR15-E190K restored the expression of target genes at levels comparable to the WT human PRDM15 (hPR15-WT), none were significantly rescued by hPR15-C844Y (Fig. 5B and fig. S5A). In addition, ChIP-qPCR analysis confirmed a reduced enrichment of hPR15-C844Y at the promoter regions of these target genes (Fig. 5C and fig. S5B), which is consistent with the failure to promote their transcription (Fig. 5B). Second, to confirm that the C844Y mutation in humans is indeed an LOF mutation, we introduced the corresponding homozygous mutation (C842Y) in mESCs using CRISPR-Cas9 technology (fig. S5, C to E). Although the C842Y knock-in allele did not affect Prdm15 transcript levels, the resulting protein was unstable and less abundant (fig. S6, A and B). qPCR confirmed that Prdm15C842Y cells express PRDM15 target genes (i.e., Rbpj, Notch3, Vangl2, etc.) at lower levels compared with WT (fig. S6C) and that endogenous PRDM15C842Y protein is unable to bind (ChIP-qPCR) to its target promoters (fig. S6D).

Our findings call for a future functional characterization of the NOTCH and PCP gene variants and should motivate targeted genetic mapping for new HPE candidates in regulators of both pathways.

We have identified new mutations in the PRDM15 gene in patients with SNRS. Although the mutations affecting the PR domain of the protein (M154K and E190K) are associated with isolated SRNS cases only, the zinc finger mutation (C844Y) causes a syndromic form of HPE. In our in vitro ESC system, these PR domain mutations reduced the stability of the encoded protein but rescued considerably the phenotypic and molecular changes induced by loss of the endogenous protein. This is consistent with the fact that these mutations in humans cause isolated SRNS only and could imply a context-dependent requirement for the PR domain. Alternatively, the differential impact of the PR versus ZNF mutations on protein stability may support a threshold model, where different levels of PRDM15 expression are required for the development of specific organ systems. On the other hand, the ZNF mutation (C844Y) had marked effects on PRDM15 function in both settings, which we attribute here to impaired binding of the mutant protein to regulatory regions of its transcriptional targets.

Similar to the LOF mutation in humans, genetic deletion of Prdm15 in mice leads to a broad spectrum of brain defects, affecting predominantly the anteriormost structures including the eyes. Such phenotypic continua are commonly assigned to allelism, polygenic origin, and the action of modifier genes. Yet, here we report that perturbation of a single transcriptional regulator can indeed affect an entire transcriptional network, relevant to both normal development and pathological manifestations.

Our findings show that PRDM15 promotes transcription of several regulators of the NOTCH and WNT/PCP pathways to orchestrate formation of midline structures. Perturbation of these transcriptional programs, upon PRDM15 depletion, disrupts forebrain development due to impaired AME specification and lack of SHH signaling, consistent with the sequence of developmental defects associated with HPE pathobiology (7).

Of note are the prominent phenotypic similarities between Prdm15 null embryos and genetic (or microsurgical) modulation of the Nodal signaling pathway in mouse. That is, Nodal hypomorphic alleles, assorted combinations of mutations in Smad2 and Smad3, as well as the mutations in the downstream effectors Foxh1 and Foxa2, all result in embryos with defective AME production and compromised anterior forebrain development (2023).

On the other hand, the characteristic ruffling of the visceral endoderm observed in Prdm15 KO embryos at E7.5 has been observed in other mutants where extraembryonic mesoderm (ExMeso) production during gastrulation is impaired, such as in loss of Smad1 (24), combined loss of Smad2 and Smad3 in the epiblast (21), or Otx2 (chimeric analysis) (25). It is, however, important to emphasize that epiblast-specific deletion of Prdm15 (Prdm15/::Sox2-CRE embryos) equally results in smaller embryos with defects in the formation of anterior structures (fig. S3). It is additionally possible that the developmental delay we observed in Prdm15 KO embryos disproportionally affects some parts of the gastrulating embryo, rather than an overall delay in epiblast proliferation before gastrulation.

On the basis of our molecular analysis, we conclude that like modulation of the Nodal signaling pathway, loss of Prdm15 specifically affects AME specification. Given the requirement of this critical signaling center in providing reinforcing anterior patterning signals, we favor a model in which its lack or dysfunction underlies the Prdm15 phenotype, rather than a paucity of mes(endo)derm produced during gastrulation by a mutant embryo experiencing developmental delay.

The restriction of HPE genetic determinants to a handful of NODAL and SHH pathway regulators stems from our limited understanding of the molecular events governing specification of early and late midline structures. Recent studies have implicated components of the WNT/PCP pathway in regulating polarity of the node along the A/P axis and linked their deregulation to structural anomalies of this critical organizing center (2629). Thus, it is not unexpected that perturbation of the WNT/PCP pathway affects the specification of APS derivatives, namely, the AME and node (29). In addition, while the links between mutations in PCP signaling and neural tube defects are well established (6, 3032), their involvement in HPE remains uncharted. NOTCH signaling, on the other hand, has been implicated in HPE only recently (33). Besides its established neurogenic role in the developing mouse telencephalon, growing evidence supports the involvement of key NOTCH regulators (for example Dll1 and Rbpj) in node morphogenesis and midline truncations (34, 35).

Our findings prompted us to perform a targeted search for mutations in a large cohort of patients with HPE. Our analysis of exome sequencing data from 132 trios and 188 singletons revealed multiple rare heterozygous variants in PRDM15 transcriptional targets involved in forebrain development. In silico protein association network analysis of these variants identified two major functional groups regulating the NOTCH and WNT/PCP pathways. We expect that our findings will encourage validation of the reported variants/mutations as well as further mining for additional HPE candidates in both pathways.

PRDM15 KO-first mice that harbor the Prdm15lacZ allele were obtained from the European Conditional Mouse Mutagenesis Program. Hemizygous (Prdm15lacZ/+) animal intercrossings were performed to obtain homozygous (Prdm15lacZ/lacZ) embryos. Further details on these animals and the conditional Prdm15fl/fl strain can be found in (10). To generate epiblast-specific Prdm15/ embryos, Prdm15fl/fl mice were first crossed to heterozygous Sox2-CRE transgenic animals [B6.Cg-Edil3Tg(Sox2-cre)1Amc/J; JAX Laboratory] (36). The resulting males (Prdm15/+::Sox2-CRE) were then crossed again to Prdm15fl/fl females. In this generation, a quarter of the progeny is expected to be Prdm15/::Sox2-CRE. The Sox2-CRE transgene was always propagated through male animals. A similar breeding strategy, using Nestin-CRE [B6.Cg-Tg(Nes-cre)1Kln/J; JAX Laboratory] transgenics, was followed to generate Prdm15/:: Nestin-CRE mice. All mice-related procedures were approved by the local Institutional Animal Care and Use Committee (IACUC) and performed in compliance with the respective guidelines (IACUC nos. 151042 and 18/10EGDM/90).

E12.5 embryos were fixed in 4% PFA (paraformaldehyde) for 48 hours before being mounted in OCT (Optimal Cutting Temperature) embedding compounds. Then, serial coronal sections of the brains (anterior-posterior) were made using a cryostat and immediately thaw mounted on poly-l-lysinecoated histological slides for hematoxylin and eosin staining.

Prdm15fl/fl; ROSA26-CreERT2 ESCs have been described in (10). For all experiments, ESCs were cultured in the conventional [serum + Lif (Leukemia Inhibitory Factor) (SL)] medium unless otherwise stated. OHT (4-Hydroxytamoxifen) (50 nM; SIGMA-H7904) was added to the culture medium overnight (O/N) to generate Prdm15/ cells.

Embryos were isolated between E6.5 and 8.5, genotyped, then processed for whole-mount in situ hybridization as described in (37) with the following probes: Foxa2, Lhx1, T, Lefty2, Chordin, Shh, Otx2, and Six3.

Full-length human PRDM15 cDNA (NM_001040424.2) was subcloned into the PiggyBac vector (DNA2.0, PJ549). Clones encoding the various PRDM15 mutations were generated using the QuickChange II XL Site-directed Mutagenesis Kit (Agilent Technologies). The sequence of primers used can be found in table S3.

To introduce the hC844Y/mC842Y point mutation, mESCs were transfected with PX458 [pSpCas9 (BB)-2A-GFP] vector expressing a guide RNA targeting the site to be mutated, along with a single-stranded oligonucleotide containing the target point mutation, to serve as a DNA repair template. Additional eight silent mutations have been introduced to avoid editing of the template by the CAS9 protein. Single clones were sorted and expanded in 2i medium. Genomic DNA was used for screening by digestion with XMN I restriction enzyme. DNA from potential mutants was cloned into the pCR 4-TOPO TA vector following the manufacturers instructions, and 5 to 10 colonies were sequenced. Details of the strategy and the sequence of the oligonucleotides used are described in fig. S5 and table S3.

To assess protein stability, Prdm15/ ESCs expressing either wild or mutant PRDM15 were treated with cycloheximide (CHX; 150 g/ml) (Sigma, no. C-7698), and then collected at different time points (2, 4, and 6 hours) for protein extraction and analysis by Western blotting. Samples collected immediately before treatment with CHX (t = 0) served as reference. Antibodies and dilutions used were PRDM15 (in house, 1:3500) and TUBA (Alpha-TUBULIN) (Sigma T5168, 1:10,000).

To assess ESC self-renewal/differentiation, cells were stained with alkaline phosphatase staining solution (AP detection kit, Millipore, SCR 004). In brief, 500 cells per well (12-well plates) were seeded in triplicates and cultured for 5 days with daily change of medium before being stained as per the suppliers recommendations.

ESCs were seeded on gelatin-coated eight-well glass slides (Millipore, PEZGS0816), at 3 103 per well, and cultured in 2i medium. Three days later, cells were fixed in 4% PFA at room temperature, permeabilized with 0.5% Triton X-100, and then blocked using 2% bovine serum albumin (BSA) for 1 hour at room temperature before O/N staining with anti- PRDM15 (in house, 1:100) at 4C. The next day, slides were washed with phosphate-buffered saline (PBS) (three times) and stained with Alexa Fluorconjugated secondary rabbit antibody at 37C (30 min). Last, slides were washed with PBS (three times) before they were mounted with a DAPI (4,6-diamidino-2-phenylindole)containing mounting medium (VECTASHIELD, Vector Laboratory H1200).

Total RNA from cells was isolated using PureLink RNA Mini Kit (Ambion, 1283-018A) according to the manufacturers instructions. RNA was retrotranscribed into cDNA using Maxima First Strand cDNA Synthesis Kit (Thermo Scientific, K1642) and subjected to quantitative real-time PCR (qRT-PCR) on an ABI PRISM 7500 machine. qPCRs (20 l) contained 10 l of SYBR Green PCR supermix (2), 4 l of a forward and reverse primer mix (final concentration, 200 nM), and 6 l of cDNA (20 ng). Primers sequences are listed in table S4.

The detailed procedure for ChIP experiments has been described previously (38); all steps were performed at 4C and protease inhibitor was added, unless stated otherwise. In brief, 20 to 40 million ESCs were fixed in 1% formaldehyde for 10 min at room temperature before quenching with 0.125 M glycine (5 min at room temperature). Cells were then washed in PBS and harvested in lysis buffer before freezing at 20C O/N. The following day, cells were pelleted by centrifugation, resuspended in ice-cold ChIP buffer, and sonicated for six cycles (30-s ON/30-s OFF) using a BRANSON Digital Sonifier (no. S540D). Lysates were then precleared for 2 hours in Sepharose A beads (blocked in 5 mg/ml BSA) before O/N incubation with PRDM15 antibody (4C). The next day, Protein A beads were added for 4 hours before washing then de-cross-linking in 1% SDS and 0.1 M NaHCO3 (65C, O/N). Last, DNA was eluted in T-buffer (pH 8) using QIAquick PCR Purification Kit, QIAGEN. Sequences of primers used in ChIP-qPCR are listed in table S4. For the E6.5 ChIP, approximately 40 to 50 embryos per experiment were pooled together and fixed immediately after isolation.

TruSeq ChIP Sample Prep Kit (IP-202-1012) was used for DNA library preparation. Sequencing was performed in the Illumina HiSeq 2000 and NextSeq 500 at the Genome Institute Singapore. Details of the bioinformatics analysis can be found in (10). In brief, the sequenced reads were aligned to the mm9 genome assembly using bowtie version 2. Peak calling was done using MACS 2.1.1 (https://github.com/taoliu/MACS). Peaks were then annotated using the ChIPpeakAnno package in Rpromoters were defined to be 5 kb upstream and 1 kb downstream of the transcription start site. Motif discovery was done using MEME-ChIP in the MEME Suite (http://meme-suite.org).

For E6.5 embryo transcriptome analysis, RNA was extracted from 8 WT and 10 Prdm15lacZ/lacZ littermates. RNA from ESCs was collected 3 days after ethanol/OHT treatment. Library preparation was performed following the TruSeq RNA Sample preparation v2 guide (Illumina). The sequenced reads were mapped to mm9 build of the mouse genome using STAR version 2.4.2a. Differential expression analysis was performed using the DESeq2 package in R. Only genes with an average FPKM (Fragment Per Kilobase Million) >1 are considered expressed. Enriched GO terms and KEGG pathway were identified using Metascape. Genes used for GO analysis were filtered based on statistical significance (P < 0.05) and fold change (log2 fold change of 0.322) in E6.5 embryo RNA sequencing. Heatmaps of gene expressions (FPKM) were generated with in-house scripts with R.

To identify potential new candidate genes associated with HPE, we searched for genetic variants in genes/proteins acting downstream of PRDM15. Exome sequencing data from a cohort of 320 patients with HPE (132 trios and 188 singletons) were evaluated. Filter criteria are as follows: allele frequency <0.0001 in ExAC database (39) de novo (if trio available); synonymous changes were omitted; and benign changes by ACMG 2015 (40) criteria were removed. To identify protein networks and functional groups, genes with potential HPE variants were subjected to protein association network analysis using STRING database (https://string-db.org).

All experiments were repeated at least three times with similar results. Each biological repeat was done in at least two to four technical replicates/independent cell cultures, where applicable. Normal distribution was assumed for all statistical analyses. Unpaired Students t test (two sided) was applied using GraphPad Prism (version 7.0) to determine the statistical significance of the observed differences. Changes were considered statistically significant when P < 0.05.

The rest is here:
PRDM15 loss of function links NOTCH and WNT/PCP signaling to patterning defects in holoprosencephaly - Science Advances

In recent years, new gene editing tools have been used for everything from genetic modification of plants to increase crop yields to, far more controversially, genetic tampering with human embryos. Could a form of gene therapy also be useful in helping treat cocaine addiction, a form of addiction that proves highly resistant to alternative approaches, such as conventional medical treatment and psychotherapy? Thats what researchers from the world-famous Mayo Clinic are hoping to prove.

They are seeking approval for the first-in-human studies of an innovative new single-dose gene therapy. Their approach involves the delivery of a gene coding for an enzyme, called AAV8-hCocH, which metabolizes cocaine in the body into harmless byproducts. In order to progress to this next step in their work, they first have to gain permission from the U.S. Food and Drug Administration (FDA) in the form of an Investigational New Drug Application.

The researchers have already demonstrated the safety of their approach in mice. In a prior experiment, they showed a complete lack of adverse effects in mice which had both been previously exposed to cocaine and those which had not.

Mice given one injection of AAV8-hCocH and regular daily injections of cocaine had far less tissue pathology than cocaine-injected mice with no vector treatment, the researchers wrote in the abstract for their paper describing the work. Biodistribution analysis showed the vector located almost exclusively in the liver. These results indicate that a liver-directed AAV8-hCocH gene transfer at reasonable dosage is safe, well-tolerated, and effective. Thus, gene transfer therapy emerges as a radically new approach to treat compulsive cocaine abuse.

This is not the first time similar work has been carried out. In February 2017, scientists at the University of British Columbia genetically engineered a mouse so as to be incapable of becoming addicted to cocaine. However, one of the researchers on the project told Digital Trends that transferring this work across to humans for possible treatment for addiction was not straightforward. Instead, that work was more focused on exploring the link between drug use and genetics and biochemistry.

Theres still a whole lot more research that needs to be done in this area. Even if the FDA grants the Mayo Clinic researchers permission for their human trials, well most likely be waiting a few years at least before this treatment could be rolled out to the general public. Its an exciting leap forward, nonetheless.

More here:
Scientists want human trials for gene therapy that could help battle addiction - Digital Trends

Get ready to look forward to some great fiction book releases in 2020! Theres many exciting books heading your way and weve rounded up a few fiction books being released between January and June. Theres thrillers, historical fiction, books exploring family and friends, and much, much more! As for authors, theres those releasing their debut novel, along with familiar names such as Stephen King, Michele Campbell, Emily Giffin, and Josh Malerman all returning with new novels!

Already being hailed as aGrapes of Wrathfor our times and a new American classic, Jeanine CumminssAmerican Dirtis a rare exploration into the inner hearts of people willing to sacrifice everything for a glimmer of hope.

An electrifying story of two ambitious friends, the dark choices they make and the profound moment that changes the meaning of privacy forever.

TheNew York Timesbestselling authors ofThe Glass OceanandThe Forgotten Roomreturn with a glorious historical adventure that moves from the dark days of two World Wars to the turbulent years of the 1960s, in which three women with bruised hearts find refuge at Paris legendary Ritz hotel.

In this riveting and disquieting thriller about the secrets and betrayals that accompany exorbitant wealthimagineCrazy Rich Asiansas written by Gillian Flynntwo sisters from a Chinese-Indonesian family grapple with the past after one of them poisons their entire family.

From theNew York Timesbestselling author ofThe Other GirlandJustice for Saracomes a thrilling psychological drama about a woman who believes she escaped a brutal murder years agobut does anyone else believe her?

From the New York Times bestselling author of The House of the Spirits comes an epic novel spanning decades and crossing continents, following two young people as they flee the aftermath of the Spanish Civil War in search of a new place to call home.

A gripping thriller about a mans quest for the daughter no one else believes is still alive, from the acclaimed author ofThe Chalk ManandThe Hiding Place.

Alternating its present-day mystery with the story of the sisters childhood and adolescence, Long Bright River is at once heart-pounding and heart-wrenching: a gripping suspense novel that is also a moving story of sisters, addiction, and the formidable ties that persist between place, family, and fate.

From the award-winning author ofStation Eleven, an exhilarating novel set at the glittering intersection of two seemingly disparate events-a massive Ponzi scheme collapse and the mysterious disappearance of a woman from a ship at sea.

After a storm has killed off all the islands men, two women in a 1600s Norwegian coastal village struggle to survive against both natural forces and the men who have been sent to rid the community of alleged witchcraft.

One of the best writers in America (The Washington Post) delivers a mesmerising new novel in which Queen Elizabeths spymasters recruit an unlikely agent for an impossible mission: the only Muslim in England.

A powerful, emotional debut novel told in the unforgettable voice of a young Nigerian woman who is trapped in a life of servitude but determined to get an education so that she can escape and choose her own future.

Perfect for fans ofWhered You Go, BernadetteandSmall Admissions, a wry and cleverly observed debut novel about the privileged bubble that is Liston Heights Highthe micro-managing parents, the overworked teachers, and the students caught in the middleand the fallout for each of them when the bubble finally bursts.

A storm-struck island. A blood-soaked bed. A missing man. Senior Investigator Shana Merchant believes it all adds up to a killer in their midstand that murder is a family affair.

As much a story of resilience as it is suffering, The Love Story of the Century is a bittersweet account of the complexities of addiction, the power of creativity, and the redemption of love.

The story of a vibrant but dysfunctional family trapped together on a ten-day Mediterranean cruisea riveting, irresistible novel from bestselling author Amanda Eyre Ward

In the tradition of Daphne du Maurier, Shari Lapena, and Michelle Richmond comes a new thriller from the bestselling author of The Lake of Dead Languagesa twisty, harrowing storyset at a prestigious prep school in which one womans carefully hidden past might destroy her future.

When an exclusive New York womens workspace is rocked by the mysterious disappearance of its enigmatic founder, two sisters must uncover the haunting truth before they lose their friendships, their careersmaybe even their lives.

The #1 Bestselling authors of The Wife Between Us andAn Anonymous Girl deliver a thriller about a circle of friends with deadly intentionswhere trust is their weapon and revenge is their trigger.

From the #1New York Timesbestselling author ofMidwivesandThe Flight Attendantcomes a twisting story of love and deceit: an American man vanishes on a rural road in Vietnam, and his girlfriend, an emergency room doctor trained to ask questions, follows a path that leads her home to the very hospital where they met.

New friends can be found in unexpected places. For Bridget and Amy, that place was the cancer ward of an Anchorage hospital. Now, as each struggles to overcome loss, they lean on each other for supportsharing suppers, laughter and tears.

A mother and daughter with a shared talent for healingand for the conjuring of cursesare at the heart of this dazzling first novel.

Brilliantly combining fact and fiction, the historical and the horrific,The Deepreveals a chilling truth in an unputdownable narrative full of unnerving moments and with a growing, inexorable sense of foreboding.

A spellbinding story of a mother with nothing left to lose who sets out on an all-consuming quest for justice after her daughter is murdered on the town playground.

WithThe Year of the Locust, Hayes has penned a breathtaking story about cutting-edge science, a government conspiracy, and one mans desperate attempt to unravel it all. (Note: According to some retailers, this title has been pushed back yet again to June 2020. The UK version is currently set to September 2020, but after years of previous release dates and delays, this could still change).

A riveting debut novel set in contemporary Seoul, Korea, about four young women making their way in a world defined by impossibly high standards of beauty, secret room salons catering to wealthy men, strict social hierarchies, and K-pop fan mania.

Sheriff Sunshine Vicram finds her cup o joe more than half full when the small village of Del Sol, New Mexico, becomes the center of national attention for a kidnapper on the loose.

The New Husbandis a riveting thriller about the lies we tell ourselves from D. J. Palmer, the author ofSaving Meghan.

Fried Green Tomatoes and Steel Magnolias meet Dracula in this Southern-flavoured supernatural thriller set in the 90s about a womens book club that must protect its suburban community from a mysterious and handsome stranger who turns out to be a blood-sucking fiend.

From theNew York Times, USA Today, and internationally bestselling author of theAngelologyseries comes a bewitching gothic novel of suspense that plunges readers into a world of dark family secrets, the mysteries of human genetics, and the burden of family inheritance.

From theNew York Timesbestselling author ofA Simple Favorcomes an electrifying domestic thriller of how one womans life is turned upside down when her brother brings his new girlfriend to visitand no one is telling the truth about who they really are.

In June of 1940, when Paris fell to the Nazis, Hitler spent a total of three hours in the City of Lightabruptly leaving, never to return. To this day, no one knows why. The New York Timesbestselling author of the Aime Leduc investigations reimagines history in her masterful, pulse-pounding spy thriller,Three Hours in Paris.

In the thrilling sequel to Bird Box, the inspiration for the record-breaking Netflix film that starred Sandra Bullock and absolutely riveted Stephen King, New York Times bestselling author Josh Malerman brings unseen horrors to life.

Told over the course of a single day in 1927,The Paris Hourstakes four ordinary people whose stories, told together, are as extraordinary as the glorious city they inhabit.

From #1New York Timesbestselling author, legendary storyteller, and master of short fiction Stephen King comes an extraordinary collection of four new and compelling novellasMr. Harrigans Phone,The Life of Chuck,Rat, and the title storyIf It Bleedseach pulling you into intriguing and frightening places.

In All Adults Here, Emma Straubs unique alchemy of wisdom, humor, and insight come together in a deeply satisfying story about adult siblings, aging parents, high school boyfriends, middle school mean girls, the lifelong effects of birth order, and all the other things that follow us into adulthood, whether we like them to or not.

If you love Jennifer Robson orThe Crownyou will loveNew York Timesbestselling author Karen Harpers novel about Elizabeth, The Queen Mother.

Peter StraubsGhost Storymeets Liane MoriartysBig Little Liesin this American Indian horror story of revenge on the Blackfeet Indian Reservation.

Fans ofThe Chilbury Ladies ChoirandThe Guernsey Literary and Potato Peel Pie Societywill adoreThe Jane Austen Society A charming and memorable debut, which reminds us of the universal language of literature and the power of books to unite and heal. Pam Jenoff,New York Timesbestselling author ofThe Lost Girls of Paris

Her own past could be a reporters biggest story in this twisting thriller about murder and family secrets by theNew York Timesbestselling author T.R. Ragan.

From Michele Campbell, the bestselling author ofIts Always the Husbandcomes a new blockbuster thriller inThe Wife Who Knew Too Much.

In this wicked debut, safecracker Michael Maven must pull off the most dangerous theft of his long careeror his friends and family will be killed.

From theNew York Times bestselling author of the Hello Sunshine Book Club pickThe Other Woman, comes a compelling new domestic suspense novel about a family who is forever changed when a stranger arrives at their door.

In the irresistible new novel from the #1New York Timesbestselling author ofAll We Ever Wanted, a woman is falling hard for a man shes just met when he disappears without a trace on 9/11.

In 1935 three women are forever changed when one of the most powerful hurricanes in history barrels toward the Florida Keys inNew York Timesbestselling author Chanel Cleetons captivating new novel.

From theNew York Timesbestselling author ofThe Last House Guesta Reese Witherspoon Book Club pickcomes a riveting new novel of psychological suspense about a young woman plagued by night terrors after a childhood trauma who wakes one evening to find a corpse at her feet.

FromTheNew York Times-bestselling author ofThe Mothers, a stunning new novel about twin sisters, inseparable as children, who ultimately choose to live in two very different worlds, one black and one white.

The female cofounders of a wellness start-up struggle to find balance between being good people and doing good business, while trying to stay BFFs.

Like Loading...

More here:
Fiction Book Releases To Check Out In 2020 - The Nerd Daily

The question, what is dominant, human nature, or nurture (culture), has been the motivating force in a debate that has waged since at least the 18th and 19th centuries for instance in the work of Jean-Jacques Rousseau (see his prize-winning Academy of Dijon essay on the question, whether human morals had improved by, or in the 18th century as a result of the arts and sciences [the Enlightenment]), and in the 19th-century debate on whether experience could be harnessed to improve people through an empiricist-oriented education, on the one hand, or (after Darwins work on the Origin of Species had appeared around mid-century) whether natural selection was the deciding factor insofar as people naturally struggled for survival as best they could, with as in the rest of nature the fittest surviving in the end.

Part and parcel of Darwins theory of evolution, was the corollary that, given the scarcity of resources, there was always an internecine struggle, a war of all against all something conspicuously assimilated by capitalism with its dog-eat-dog pseudo-ethos. In the 20th-century the science of genetics made impressive strides, with the result that most people today would probably support the claim that our inherited genetic endowment is more decisive than our cultural (including educational) surroundings in determining our character or personality, and hence, our actions. A more balanced view (which I support, and which is found among some geneticists too) amounts to the claim that both genetics and cultural forces contribute to our personalities and the manner in which we choose, or act.

In Freuds parlance, this is tantamount to saying that the countervailing drives, or instincts, namely Eros (the life-drive, at the basis of all constructive cultural behaviour) and Thanatos (the death drive, underpinning all aggressiveness and conservative tendencies to hang on to the familiar rather than try something new) always find their expression in culture. For example, Thanatos is tamed and channelled into acceptable behaviour through sport, and Eros finds expression in a great variety of erotic practices in different cultures. Put succinctly: if Eros and Thanatos are part of our nature, culture mitigates their unbridled expression by means of mediating cultural practices.

But what happens if, instead of culturally mitigating or sublimating (as Freud might say) these natural forces within us through cultural institutions and habits, the latter turned out to exacerbate them instead? This, it seems to me, is the theme of the riveting television series (CBS and Warner Bros., 2014 to the present), The 100, developed by Jason Rothenberg and based on a novel-series by Kass Morgan.

The 100 is a post-apocalyptic narrative reminiscent of Ronald D. Moores Battlestar Galactica, but while the latter long-running series deals, like the Terminator movies, at length with the threat posed to humans by Artificial Intelligence in the form of robots (or Cylons), The 100 is less concerned with this theme than with the threat posed by humans to themselves that is, to their own survival and that of a habitable environment (although an AI called A.L.I.E. is responsible for the nuclear apocalypse that wipes out almost all life on the planet in a programmed effort to solve the problem of human overpopulation). And the series locates this threat squarely in the inability of humans to restrain or defuse the death drive (Thanatos) in the guise of endemic, irrepressible, mutual aggressiveness, which asserts itself with sickening regularity, the attempts at peacemaking on the part of some characters notwithstanding.

The title of The 100 indexes the 100 juvenile criminals that are sent back to Earth from the orbiting Ark (to which some humans retreated), 97 years after the nuclear devastation, in an effort to determine whether conditions have improved to the point where they can return to Earths surface. It is not my intention here to reconstruct the entire, convoluted narrative, covering 6 seasons (with another, final season in the making; for that readers may consult Wikipedia. Rather, I want to highlight aspects of the series that bear out my contention, that it thematises the inability of humans to overcome, let alone eradicate, their innate tendency diagnosed not only by Freud, but long before him by Thomas Hobbes, too to engage in mutually destructive aggression towards one another, even when peace beckons as a possibility.

This is demonstrated early in the series when the eponymous 100 young people encounter other people on Earth who are the descendants of those who survived the nuclear catastrophe. Despite the efforts of some of the 100, to enter into a relationship of peaceful coexistence with the so-called grounders who are armed with swords, spears and bows and arrows others among them torpedo the effort by attacking the grounders with their guns and initiating a cycle of conflict.

This pattern continues throughout the series various seasons, not only regarding the fraught relations between the 100 together with, eventually, the rest of the people from the Ark, who join them on the earths surface and the grounders, led by a revered Commander called Lexa, but also between the people from the Ark (called Skykru) and a group of people who survived the nuclear holocaust by retreating into a huge underground bunker in Mount Weather (with whom the grounders have been in conflict for decades). Add to this that conflict also erupts intermittently within the ranks of Skykru, as well as of the various clans of grounders, and it becomes very clear that, in this series, people are ruled by the death drive, despite the efforts of some to defuse it.

One of the original 100, a character called Jasper, articulates this explicitly on more than one occasion when he tells his friend, Monty, that as demonstrated by one disastrous, human-induced calamity after another humans are the problem, and that the only solution is to break the cycle that is, for humans to eradicate themselves (as Jasper and a group of like-minded individuals actually do when they commit collective suicide in the face of another nuclear disaster, when all the remaining nuclear power plants on the planet go into meltdown). Much as one might want to disagree with such an extremely pessimistic anthropology, one cannot help but agree with the fictional Jasper just look at the state of the world around us: Trump launching an assassination of an Iranian general that is bound to provoke more reprisals than just the Iranian rocket attacks on American positions in Iraq, reported today; the evidence that has come to light of arson in the devastating wildfires in Australia; the mounting evidence that humans are exacerbating, rather than ameliorating, the rapidly worsening climate conditions on the planet, and so on.

In The 100 this pessimism concerning humans proclivity for destruction is given an additional twist, insofar as some of the most (initially) appealing characters including (but not limited to) Clarke, Bellamy and his sister, Octavia are shown as causing destruction and death despite their contrary intentions. Which reminds one, yet again, of the wisdom of the Bard William Shakespeare. Recall that, in King Lear, when the tragic events set in motion by a vain old king have started running their devastating course, Cordelia his favourite, and only honest daughter, to boot exclaims: We are not the firstWho with best meaning have incurrd the worst.

In a book written late in his life Religion within the Limits of Reason Alone the Enlightenment philosopher, Immanuel Kant, distinguished between two kinds of evil: radical evil and demonic (or diabolical) evil. The first, radical variety (from the Latin for root), is the evil that we cannot ever eradicate (uproot) from our being as a constant possibility (because we are morally free beings), even if we can choose against it. The second diabolical evil which Kant rejected, lest it undermine the very possibility of ethics, would be a kind of evil that would make of humans devilish beings insofar as we would always, without fail, do evil even when we intend to do good. It seems to me that the notion of evil that underpins The 100 is precisely such diabolical evil and this alone should give us pause.

Originally posted here:
Human 'nature' as explored in a riveting television series: 'The 100' - Thought Leader

Jan 08, 2020 11:04 AM EST

There are 500 animals studied so far in the mouse lemur project, a collaboration that aims to parse the genetics of this diminutive, prosimian primate. It is the brainchild of Stanford biochemist Mark Krasnow.

Because all 24 species of mouse lemurs look similar, the most reliable way for scientists to tell them apart is through genetic testing. (Scientists have recently identified three new species of mouse lemurs in Madagascar.)

They are quite possibly the answer to medical researchers' dreams.

This world's smallest primate may soon replace fruit flies, worms, and even mice as the primary lab animal for scientific research.

According to Stanford University School of Medicine researchers, they have the potential to serve as an ideal model for a wide range of primate biology, behavior, and medicine, including cardiovascular disease and Alzheimer's disease.

Mice, fruit flies, and worms as genetic models have routinely failed to mimic many aspects of primate biology, including many human diseases, said Mark Krasnow, MD, Ph.D., professor of biochemistry.

Krasnow and his colleagues turned to the mouse lemur and began conducting detailed physiologic and genetic studies on them.

It was reported that they already have identified more than 20 individual lemurs with unique genetic traits, including obesity, high cholesterol, high blood sugar, cardiac arrhythmias, progressive eye disease and motor and personality disorders.

The researchers hope it will soon become a genetic model organism that will help us better understand many aspects of primate biology, behavior, and health, including lemur and human diseases.

According to the June issue of GENETICS, Ezran et al.'s genetic research on these primates began as a project for three high school laboratory interns to find an appropriate model organism for primate genetics.

Mouse lemurs are more human than mice, as genetic research on mice has led to countless important discoveries, but their physiology and behavior differ in many ways from that of humans and other primates. They potentially rival the common laboratory mouse Mus musculus, at least for certain questions.

Mice, fruit flies, and worms were the prototypical lab specimen because they were inexpensive to maintain, easy to study, and reproduced quickly enough to offer researchers a constant stream of samples. According to Krasnow, MD, Ph.D., a professor of biochemistry at Stanford University, the genetic makeup of the 3 animals hasn't been a close enough match to humans to work well for the studies today's researchers need to conduct.

Krasnow's project is studying a large population of grey and brown mouse lemurs - Microcebus murinus and Microcebus rufus, respectively - in the wild to work out how their genes link to differences in biology, health, and behavior.

Other than being closely related to humans, they still have many of the advantages of mice in terms of small size, rapid reproduction, and relatively large litters.

These researchers hope that continued study of these abundant primates could lead to a better understanding, and possibly better treatments, of these and other conditions in lemurs and humans.

RELATED ARTICLE: DNA Analysis Helps Researchers Identify New Mouse Lemur Species

2018 NatureWorldNews.com All rights reserved. Do not reproduce without permission.

Original post:
Mouse Lemurs Just Might Be the Next Big Thing in Genetics - Nature World News

In 1891, a French physician named Albert Calmette opened a research outpost in what was then Saigon (now Ho Chi Minh City, Vietnam) to develop new vaccines for rabies and smallpox. Then the Indian cobras showed up.

The invaders sank their fangs into several of Calmettes new neighbors, injecting molecules that rotted muscles, ruptured blood vessels, and paralyzed the nerves that told their hearts to beat and lungs to breathe. Their grisly deaths prompted him to drop infectious disease and focus on snake venom. When he returned to France, he injected Indian cobra venom into rabbits in small doses and discovered that the animals produced a serum with a protective effect: the first antivenom. Calmette began producing his anti-cobra cocktail of antibodies in donkeys and horses and in 1895, for the first time, successfully treated a human snakebite victim.

Calmettes method still dominates antivenom production todaya practically medieval process of snake milking and horse blood harvesting that is laborious, expensive, and error-prone. What scientists have needed in order to modernize this operation is the source code for a snakes noxious protein soup, the actual genes and nearby DNA that turn them on or off.

After two years of work, an international team of scientists has now published, in Nature Genetics, an atlas of all 38 of the Indian cobras chromosomes, the most complete snake genome ever assembled. It contains information no one has ever been able to piece together before: the genetic recipe for the snakes deadly venom cocktail. Theyre hoping it will serve as a roadmap to bring antivenom production into the 21st century.

It seems like something we should have figured out 20 years ago, but until now those areas of the snake genome have been total black boxes, says Todd Castoe, an evolutionary geneticist at the University of Texas at Arlington who was not involved in the work. Initially, scientists believe, the genes that generate venoms carried out totally different functions, usually some innocuous cellular housekeeping task. But along the way they duplicated, a common DNA-copying error. And then the extra copies acquired mutations. That happened over and over, and the proteins they produced became deadly in different ways. The result of all this evolution is that the stretches of DNA that code for venom toxins are full of repetitive sequences, making them exceedingly difficult to properly assemble. Imagine trying to solve a jigsaw puzzle where the same fluffy clouds are scattered six, eight, a dozen times in the same corner of the sky. How do you know which piece goes where?

To finally fit together these elusive sections of the genome, Somasekar Seshagiri, a geneticist and president of the SciGenom Research Foundation in Bangalore, and his collaborators used a combination of older sequencing methods with new ones that read out very long stretches of DNA. They also employed a technique that detects the 3D shape of DNA to further refine their guesses about how exactly to stitch together the structurally finicky venom regions. With the full genome in hand, the researchers then analyzed which sections of it are turned on in the venom gland but not in other tissues. That allowed them to identify the code that spells death or disablement for anyone who encounters the cobras bite.

Antivenoms will no longer just be like some magic potion we pull out of a horse.

Somasekar Seshagiri

Indian cobra venom isnt just one poison; it consists of more than a dozen toxins and other substances that together launch a coordinated attack on the snakes prey (or a hapless human victim). In the Nature Genetics paper, Seshagiris team identified 19 genes key to producing this lethal brew. For the first time, it establishes the links between a snakes toxins and the genes that encode them.

The achievement not only shows scientists how to use the same methods to sequence other venomous snake species, it also unlocks the door to modernizing antivenom production. The value of genomics is that it will allow us to produce medicines that are more concretely defined, says Seshagiri. Antivenoms will no longer just be like some magic potion we pull out of a horse.

Read more:
Scientists Figured Out the Indian Cobra's Genomeat Last - WIRED

THOUSAND OAKS, Calif., Jan. 7, 2020 /PRNewswire/ -- Amgen (NASDAQ:AMGN) will present via video conference at theGoldman Sachs 12th Annual Healthcare CEOs Unscripted Conference at1p.m.PT on Thursday, Jan. 9, 2020. Robert A. Bradway, chairman and chief executive officeratAmgen, and Peter H. Griffith, executive vice president and chief financial officerat Amgen, will present.Live audio of the presentation can be accessed from the Events Calendar on Amgen's website,www.amgen.com, under Investors.A replay of the webcast will also be available on Amgen's website forat least90 days following the event.

About AmgenAmgen is committed to unlocking the potential of biology for patients suffering from serious illnesses by discovering, developing, manufacturing and delivering innovative human therapeutics. This approach begins by using tools like advanced human genetics to unravel the complexities of disease and understand the fundamentals of human biology.

Amgen focuses on areas of high unmet medical need and leverages its expertise to strive for solutions that improve health outcomes and dramatically improve people's lives. A biotechnology pioneer since 1980, Amgen has grown to beone ofthe world'sleadingindependent biotechnology companies, has reached millions of patients around the world and is developing a pipeline of medicines with breakaway potential.

For more information, visitwww.amgen.comand follow us onwww.twitter.com/amgen.

CONTACT: Amgen, Thousand OaksJessica Akopyan, 805-447-0974 (media)Trish Hawkins, 805-447-5631(media)Arvind Sood, 805-447-1060 (investors)

SOURCE Amgen

http://www.amgen.com

Go here to read the rest:
Amgen To Present At The Goldman Sachs 12th Annual Healthcare CEOs Unscripted Conference - PRNewswire

Brian Lee

Associate professor, Drexel University

The question of autisms heritability is compelling for researchers and laypeople alike, but many people in both groups misunderstand its definition.

Heritability is defined as the proportion of variation in a condition that is attributable to variation in genetics. Heritability estimates can influence how much time and money researchers like me think should be allocated to studying genetic factors versus environmental ones. For families with a history of autism, heritability estimates get right to the heart of the nature-versus-nurture debate, by offering clues about which factors led to an individuals diagnosis.

These numbers have substantial implications; they probably should not. Autism arises from a complex interplay of genetic and environmental factors, and most heritability studies oversimplify these relationships.

Several studies on autism heritability published in the past few years have drawn considerable attention. Those published from 2011 to 2014 estimated heritability to be in the 35 to 50 percent range, but studies published since 2017 have put the number at 64 to 85 percent.

What do these estimates actually mean?

Heritability is often misinterpreted as the proportion of a condition that is caused by genes. However, that interpretation is not quite correct. Or rather, so many asterisks must be attached in order for it to be correct, that it could not be, by any stretch of the imagination, considered to be correct.

Heritability estimates may tell us to what extent a persons genetics predispose them to a condition. But they tell us nothing about how different environments cause those genetics to play out.

First, let me explain why most estimates of heritability are incorrect. Studies that estimate autisms heritability use a statistical model to try to attribute the condition to either genetics or environment. Mounting evidence suggests this model is too simplistic to explain how autism arises.

The model generally looks something like this: Observed characteristics, or phenotype (P) = genotype (G) + environment (E). The G and E components can each be broken down further to get at specific types of genetic or environmental contributions, but the core point of the model is to separate G and E.

A statistical model is merely a caricature of the real world, though; the extent to which it is useful depends on how well the model reflects reality. The P = G + E model assumes that genetic and environmental influences are independent of each other and that genes do not interact with the environment or with other genes to influence phenotype.

We know in fact that networks of genes interact to influence a persons odds of having autism and that genetic factors raise the odds of having autism caused by environmental exposures such as infection, air pollution or nutrition.

In short, if reality is more complex than the model, that model may produce inaccurate heritability estimates. There are many more technical reasons why published heritability estimates are likely to be inaccurate1.

There is also a much simpler reason why heritability estimates should not be taken at face value: High heritability does not equal genetic causation, and it does not exclude the possibility of environmental influence.

Here are two thought experiments that demonstrate why.

Borrowing an example from the great evolutionary biologist Richard Lewontin, imagine planting a set of identical seeds in a uniform environment that ensures all the seeds receive equal amounts of light and nutrients. Any variation in the heights of the plants that grow from those seeds is solely attributable to genetic variation among the plants. The heritability in this scenario is 100 percent.

Now imagine taking another set of the same seeds and planting them in uniformly suboptimal growing conditions, with limited light and nutrients. The plants growth would be stunted, and again the heritability would be 100 percent.

The point is: Even where heritability is estimated to be 100 percent, the environment can influence phenotype. Of course, this is not limited to plants. For example, the heritability of human height is estimated to be approximately 80 percent, but height is still strongly regulated by a persons nutritional environment.

Next, consider this example from David S. Moore and David Shenk2. Imagine a bucket of water into which person A pours 40 liters of water and person B pours 60 liters of water. Clearly, 40 percent of the water is attributable to person A, 60 percent to person B. Now imagine the same bucket, but this time person A turns on the faucet and person B holds the hose. How much of the water in the bucket is due to person A and how much is due to person B?

In short, when causes interact to create an outcome, it becomes nonsensical to try to apportion credit (or blame) to one cause independent of the other.

The bucket example is not just a thought experiment; it represents conditions that have both genetic and environmental components.

Consider the condition phenylketonuria, which occurs in people who have genetic variants that affect how their bodies metabolize the amino acid phenylalanine. The condition does not occur in the absence of the genetic variants, but it also does not occur if phenylalanine is removed from the diet. So how much of it can be attributed to genes versus the environment?

The consequences of miscasting heritability as the contribution of genetics to any given individuals diagnosis are potentially dire. As well as misinforming the public, it could throw funding for research on the etiology of autism entirely into genetic research rather than into how genes and environment interact.

This should cause genetic and environmental researchers alike great concern.

The search for rare genetic variants that may cause autism has yielded many important findings, but the search for common variants, whose influence combines to raise autisms odds, has been less fruitful. There are likely to be many of these variants, each exerting only weak effects, which makes them undetectable except in massive study samples. It is also highly likely that many common variants do not exert an effect unless they are present along with another genetic or environmental factor.

Animal models that explore genetic factors in the absence of relevant environmental interactions could be doomed never to recapitulate those genetic factors effects in people.

In short, many heritability estimates of autism in the literature are likely to be inaccurate and, more importantly, prone to misinterpretation. Rather than asking: Are genes or the environment responsible for autism? we should be asking: How are genes and the environment responsible for autism?

Brian Lee is associate professor of epidemiology and biostatistics at Drexel University in Philadelphia, Pennsylvania.

Read the original post:
Autism heritability: It probably does not mean what you think it means - Spectrum

The future of anxiety treatments could go the way of oncology and cardiology, as scientists inch closer to treating the condition using precision medicine drug treatments that are specifically tailored to ones genetic and biochemical profile. Anxiety is notoriously hard to treat using standard therapies, but a precision medicine approach promises to actually work.

But to know what genes to target using precision medicine, you have to know where to look. In the largest genetics study of its kind to date, scientists reveal regions in the human genome that appear directly related to anxiety risk five are found in the genomes of Americans of European descent, and one in black Americans.

The findings were published this week in the American Journal of Psychiatry.

The researchers used data from nearly 200,000 participants in the United States Million Veteran Program one of the worlds largest genetic biobanks. Daniel Levey, a postdoctoral associate at Yale School of Medicine and co-lead author of the study, described the dataset as one of the greatest resources in the world for conducting this kind of research.

Levey tells Inverse that the study identifies the locations in the genome where genetic variation is common in most people. In turn, people who have variation in these locations have increased risk for anxiety symptoms.

But theres a chance that people at a higher genetic risk for anxiety will not develop the disorder, Levey says.

Genetics are an important piece of the puzzle for understanding human health, but they are not fate, Levey says. The variants we identified are responsible for an increase in overall risk, but that genetic risk interacts with other environmental and lifestyle factors.

The team analyzed the genomes of 199,611 participants and looked at whether they had a self-reported diagnosis of anxiety or panic disorder.

In Americans of European descent, the researchers identified five locations on the human genome related to anxiety. The study is notable because it is may be the first to produce significant findings on the genetics of anxiety among people of African ancestry (about 18 percent of the participants were black). The identified region is at the TRPV6 gene the genetic variant only occurs in people of African ancestry.

A risk region of particular interest is one near the gene SATB1, Levey says. This gene interacts with the hypothalamic-pituitary-adrenal axis, which is the biological pathway associated with the stress response. The result may point to a novel understanding of how genetics influence the stress response and anxiety, he says.

The findings jibe with the theory that the traits of some psychiatric conditions overlap because they share genetic roots. The researchers found high genetic overlap between anxiety symptoms and depression, post-traumatic stress disorder, and neuroticism.

Historically, the genetics of anxiety disorders has lagged behind other related conditions, including depression. In 2018, scientists discovered that there are at least 82 genes linked to depression in part explaining why 50 percent of cases are caused by genetics.

The authors of the 2018 study hoped that identifying genes could lead to new treatments. Levey shares the same hope: Other researchers can take what this study has accomplished, and expand upon the findings to develop novel therapies. Theres also a need for larger studies that can identifying more of the genetic architecture underlying anxiety disorders, he says.

In the future, perhaps awareness of increased risk for anxiety disorders may lead people to seek out treatment and empower them to seek training in coping strategies to be more resilient, Levey says.

Partial abstract:

Background: Anxiety disorders are common and often disabling. They are also frequently comorbid with other mental disorders such as major depressive disorder with which they may share commonalities in their underlying genetic architecture.

Methods: We used one of the largest homogeneously phenotyped cohorts available, the Million Veteran Program, to perform a genome-wide association study (GWAS) a continuous trait for anxiety (GAD-2, N=199,611) as the primary analysis and self-report of physician diagnosis of anxiety disorder (SR-ANX, N=224,330) as a secondary analysis).

Conclusions: We present the largest GWAS of anxiety traits to date. We identified novel genome-wide significant associations near genes involved with global regulation of gene expression (SATB1) and the estrogen receptor (ESR1). Additionally, we identified a locus (MAD1L1) which may have implications for genetic vulnerability across several psychiatric disorders. This work provides new insights into genetic risk mechanisms underpinning anxiety and related psychiatric disorders.

More:
Largest-ever study on genetics of anxiety points to new treatments - Inverse