The Sleeping Embryo

2026-07-22

The implantation of the blastocyst into the uterine wall is a key step of the reproductive cycle, which mediates the connection of the embryo to the maternal tissues during the early stages of pregnancy. However, in some species, including the house mouse, this process can be put on hold, while the embryo falls into a reversible state of suspended animation, known as diapause. The dormant embryos can reside in a “deep sleep” over extended periods of time (e.g. bypassing unfavourable environmental conditions), without compromising their developmental potential. Although, the maternal hormonal control of implantation and the process of transient mouse embryogenesis have been intensively studied, the embryonic diapause is still an extremely enigmatic state. Several lines of evidence, based on my preliminary data, suggest that diapause is not a stasis, but instead is a dynamic process with underlying mechanisms that can appear redundant during transient embryogenesis. Here I aim to decipher the cryptic embryo-intrinsic mechanisms of embryo dormancy, using the mouse as a model system. I will elucidate the cellular processes that coordinate and capacitate the embryo for diapause on epigenetic, transcriptional and cell signalling levels. Using interspecies chimeras and blastoids, I will extend my analysis to non-diapausing species and artificial embryo-like structures. Thus, by manipulating the flow of embryogenesis, I will uncover hidden, dormant mechanisms, safeguarding the developmental potential of the early mammalian embryo.

Germany

2025-12-15