New European Medical Journal paper: The Epitranscriptomic Landscape in Early Mammalian Embryonic Development: A Narrative Review
Postdoc Sophie Bresson, member of the RNA modifications in development and disease group led by Yanjiao Li at the Department of Microbiology, is the first author of this new paper published in European Medical Journal (EMJ) – Reproductive Health.
In this new narrative review the authors highlight an emerging layer of regulation that helps control this transition: chemical modifications to RNA, collectively known as the epitranscriptome.
The Maternal-to-Zygotic Transition as an RNA-Regulated Process
The earliest stages of mammalian development depend on highly coordinated molecular control. Immediately after fertilisation, the embryo relies on maternal RNA and proteins stored in the oocyte. Within only a few cell divisions, these inherited instructions must be selectively removed as the embryo begins to activate and use its own genome. This process, known as the maternal-to-zygotic transition, is essential for normal development.
Early embryonic development involves carefully timed maternal RNA clearance and activation of the embryonic genome. These events have traditionally been studied mainly through transcription factors, chromatin and DNA-based regulation. The review emphasises that regulation at the RNA level is equally important.
RNA modifications
RNA modifications, RNA editing and RNA cap modifications influence whether individual RNA molecules are stabilised, translated into proteins or degraded. These processes are controlled by specialised proteins often described as “writers”, “readers” and “erasers”. Together, they help ensure that the correct RNA instructions are available at the appropriate stage of development.
The review brings together current knowledge of these mechanisms during early mammalian development and identifies several important unanswered questions. In particular, more research is needed to understand how RNA modifications interact with one another, how their functions change between developmental stages and how disruption of RNA regulation may influence reproductive outcomes.
Clinical Relevance and Future Directions
Epitranscriptomics is still an emerging research field, and much of the current evidence comes from animal models. However, possible links to human reproductive health are beginning to emerge. Abnormal expression of RNA modification regulators has been associated with conditions including fetal growth restriction, primary ovarian insufficiency, early menopause and recurrent miscarriage. The review therefore suggests that disrupted RNA regulatory pathways may contribute to infertility and impaired early development.
The epitranscriptome offers a new window into the biology of early embryos and reproduction. However, progress in the field is limited by the very small amounts of biological material available from oocytes and early embryos.
Potential New Biomarkers and Therapeutic targets
Further technological development is therefore essential to advance the understanding of Epitranscriptome in this field. Advances in single-cell and low-input methods will make it increasingly possible to detect and measure RNA modifications in rare samples. Only by identifying how these modifications change across developmental stages, biological conditions and reproductive disorders can researchers begin to define their functions more clearly.
In the longer term, a better understanding of epitranscriptomic regulation may support the discovery of new biomarkers and therapeutic targets in reproductive medicine. Such developments could eventually contribute to improved diagnosis and treatment of infertility and early pregnancy loss, although substantial biological and clinical validation will still be required.
Links:
The EMJ paper:
The Epitranscriptomic Landscape in Early Mammalian Embryonic Development: A Narrative Review - European Medical Journal
Research group homepage:
RNA modifications in development and disease, headed by Yanjiao Li
Centre for Embryology and Healthy Development (CRESCO)