Epigenetics and bioethics of human embryonic development: a birds’ eye perspective – BioNews

5 July 2021

It is becoming clear that our gene functions are influenced by a variety of epigeneticfactors throughout our lives and even before we are conceived. Environmental context may affect gene expression and which genes are 'activated' or not in children conceived via IVFmay be influenced by the dietary and lifestyle habits of an embryo's parents or grandparents, as well as by the culture medium in which eggs and embryos are kept in vitro. These findings have implications for the way we think about fertility, assisted reproduction, and genetic identity.

Epigenetics and bioethics of human embryonic development is a multidisciplinary project that spans disciplinary boundaries in order to better understand how scientists, clinicians, patients, and society should respond to these challenges. The project is funded by the University of Oslo Life Sciences, as part of its convergence environments initiative which has seeninterdisciplinary research groups formed to address major health and environmental challenges faced. The project started in 2017, and is now drawing towards its close. Here, three of our project members explain their work within the project.

Trine Skuland is a developmental biologist who works on epigenetic regulation of early embryo development.

When an egg and a sperm unite to form a zygote, numerous events need to be coordinated in order to achieve successful development. Out of the ~30,000 human genes, the right selection has to be switched on/off at the appropriate time point. No wonder these events are error-prone!

Upon fertilisation, extensive reprogramming happens in order to reset the epigenetic marks of the egg and the sperm DNA, and to set up a new pattern that is compatible with further embryo development. Epigenetic marks are chemical groups that are attached either to the DNA itself or to the proteins the DNA wraps around inside the cell nucleus. The pattern of these epigenetic marks will decide whether genes are activated or silenced.

When an embryo reaches the eight-cell stage, one of the most critical events takes place. This is when the first major set of genes is activated. My team is currently studying one specific epigenetic mark that we think is important for the embryonic genome activation and we hope our research will contribute in further characterisation of epigenetic factors involved in this crucial part of embryo development.

Our aim is to find another piece of the big genome activation puzzle in order to get a more complete picture of what is necessary for normal embryo development. This is as more than half of the embryos created during assisted reproduction develop abnormally and have to be discarded. Our ultimate goal is giving infertile people higher quality embryos to increase their chances of becoming parents.

Birgit Kvernflaten is a medical anthropologist who looks at prospective parents' experiences of assisted reproductive technologies.

My role in the project is to explore prospective parents' experiences and perspectives of practices and treatments used in assisted reproduction.It starts from the idea that their experiences do not take place in a vacuum, but are shaped within a particular socio-cultural and political context. The project further aims to explore and understand prospective parents' experiences and perceptions of the status of the embryo, embryo donation, research, and selection, in light of increased epigenetic knowledge.

This project has highlighted how prospective parents' experiences of infertility treatment are related to and shaped by social and cultural discourses on Norwegian family life.

In Norway, biological or genetic ties are considered central to people's understanding of kinship and identity, shaping couples' negotiations about gamete donation, family, relationships, and responsibilities. Yet people's understanding of genes is also ambiguous. As for the concept of epigenetics; it seems it has not yet entered the public's imagination.

Although the role of environmental factors in shaping who we are is acknowledged in Norwegian society, couples tend to view genetics in a rather deterministic way, in that they believe it shapes both looks, personality, and risk of disease. While difficult to truly grasp, the role of genetics is central to people's ideas about reproduction and parenthood. New epigenetic knowledge raises questions about the interface between nature and nurture, as well as opening up discussion related to the role mothers and their bodies play in determining the health of future offspring.

Joona Rsnenis a bioethicist who works on the philosophical and ethical implications of epigenetics.

Epigenetics raises challenging ethical issues throughout the human life cycle. Epigenetic transmission from one generation to the next may raise questions of moral responsibility of parents and grandparents. Epigenetics plays an important role in a range of chronic diseases, such as diabetes. Our lifestyle habits during pregnancy and even before, may influence whether our future children will live healthy lives or suffer from lifelong illness.

It is commonly known that we should eat healthily for our own sake, but these developments in our understanding of epigenetic could imply that we should eat healthily for the sake of our future children as well. Does this demand too much of future parents?

Epigenetics seems to put prospective parents under pressure since they would be partly responsible for their future child's health even before the child is conceived. Pregnant women are often advised to abstain from alcohol and tobacco, but maybe it is worth reminding them to eat healthily as well and this advice applies not only to future mothers, but to prospective fathers too, since epigenetic inheritance occurs through the male germline as well.

Conclusion

The interplay between science, anthropology, and philosophy in the context of epigenetics is complex.Skuland notes that a key aim for scientists working to unravel the epigenetic mechanisms involved in early embryo development, is to fulfil the needs of IVF patients to have their 'own' child. Dr Kvernflaten shows how genetics is central to patients' ideas about kinship and identity, yet epigenetics is still something unfamiliar to most prospective parents. Rsnen's example suggests that if parents did take on board some of the moral implications of epigenetics, they might find that the scope of their responsibility for future offspring is dramatically expanded.

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Epigenetics and bioethics of human embryonic development: a birds' eye perspective - BioNews