The transcriptional activation of the embryonic genome (EGA) is a key event in early development, marking the transition from maternal control to the embryo’s own genetic regulation. However, the details of how this process works and how it varies across different species are still not fully understood. To explore this, researchers at Helmholtz Munich developed a new technology, Smart-seq+5′, which allows for high sensitivity and full-length transcript coverage from individual cells and embryos. This method enables the capture of important transcript information at the very beginning of development.

By using Smart-seq+5′, the team studied 34 developmental stages in five mammalian species, providing valuable insights into how genes are activated before, during, and after EGA. One surprising discovery was the extensive transcription driven by transposable elements (TEs), which are sequences of DNA that can move around in the genome. In fact, the study found over 19,000 genic (gene-related) transcripts influenced by TEs, suggesting that these elements play a significant role in the development of embryos across different species. Interestingly, TEs were found to be active in similar ways across species, but there were also species-specific differences in how they were regulated.

This research offers new insights into the complex processes that control the development of mammals and opens up new possibilities for understanding how our genes are regulated during early stages of life. By better understanding the role of transposable elements in early development, scientists can explore how these elements may have influenced evolution and how they contribute to both shared and unique traits in different species.

Availability – https://embryo.helmholtz-munich.de/shiny_embryo/