Researchers have made a groundbreaking discovery that human cells possess an innate ability to temporarily pause their development, similar to the diapause mechanism observed in some mammals. This finding has significant implications for our understanding of early human life and could pave the way for advancements in reproductive technologies.
Unlocking the Secrets of Embryonic Diapause
That too by researchers at the Max Planck Institute for Molecular Genetics in Berlin and the Institute of Molecular Biotechnology (IMBA) of the Austrian Academy of Sciences in Vienna, the study led them to conclude that molecular mechanisms that put a hold on human cells can also mediate embryonic diapause as seen functioning across other mammalian species.
Diapause is a phenomenon in which the embryo development of some mammals, stops and rests at an early stage shortly before in utero implantation for hours or days until the surrounding circumstances become more favorable. This was believed to represent an inactive period where the embryo floats free, and for an extended period of pregnancy during which both mother and fetal development are synchronized to improve their chances of surviving.
The ability of blood cells to “pause” and remain functionally inactive is not a new idea, but until now little was known about whether human cells could do the same in our bodies. In a study published in Cell Stem Cell in May, the researchers showed that by controlling the mTOR signaling pathway, which is known to play essential roles in growth and development, they were capable of inducing human stem cells as well as stem cell-derived blastocyst-like structures (blastoids) into a diapause-like state. In this resting stage, the occurrence of cell division decreases, however, the growth of the embryo slows down and cell attachment to uterine lining also goes down.
Implications for Reproductive Medicine
This finding that there’s a ‘pause button’ in human cells has major implications for biomedical research aimed at treating and preventing serious genetic conditions. First of all, it is well-established that quicker embryonic advancement associates with higher in vitro preparation (IVF) achievement. It might be possible to do this by increasing mTOR activity, so that IVF procedures are more likely to result in a viable embryo.
In contrast, being able to induce a dormant state in the context of IVF might allow a longer period for the embryo to be assessed as healthy and for synchrony with the uterus of the mother to result in better implantation. Fortunately this dormant state is reversible, the blastoids return to normal developmental trajectory when mTOR pathway is reactivated.
The team found their discovery of cells that can reset developmental clocks within the ovary are unable to do so in other parts of a frog until it hatches, adding further mystery to what kind of evolutionary benefit there might be for living things that can pause development. Although we appear to have lost the ability for women to pause during pregnancy, the team think that this mechanism may still be there but dormant, and could in future be switched on with novel scientific explorations.
Conclusion
A human have been born with a ‘pause’ button for development — A rare human organism, above all primate kin, of potential interest to a bioactivist!?! The discovery not only adds a new piece to the puzzle of how animals’ organs form inside their bodies, but may also improve reproductive technologies and bolster success rates for IVF. While new research will undoubtedly reveal a variety of potential implications and applications, but at baseline — the fact that development and maternal nutrition can be briefly paused has far-reaching implications for immunoengineering and for treatment of infertility.
