Researchers at the Max Planck Institute for Molecular Genetics and the Institute of Molecular Biotechnology (IMBA) of the Austrian Academy of Sciences have discovered a potential “pause button” in the earliest stages of human development. The study suggests that humans may be able to control the timing of their development by activating this “pause button.” This discovery has significant implications for our understanding of early human life and could improve reproductive technologies.
In some mammals, a mechanism called embryonic diapause allows for the temporary slowing of embryonic development, often at the blastocyst stage before implantation in the uterus. During diapause, the embryo remains free-floating, extending pregnancy for weeks or months until favorable conditions for development resume. While not all mammals use diapause, this ability to pause development can be triggered experimentally. The question of whether human cells can respond to diapause triggers has remained unanswered.
In a recent study by researchers at the Max Planck Institute for Molecular Genetics and the IMBA, it was found that the molecular mechanisms controlling embryonic diapause could also be activated in human cells. The study used human stem cells and blastoids, stem cell-based blastocyst models, as ethical alternatives to studying embryos. Modulation of the mTOR signaling pathway induced a dormant state in these models, similar to diapause, characterized by reduced cell division and slower development. This dormant state was reversible, with blastoids resuming normal development when the mTOR pathway was reactivated.
The findings suggest that humans may possess an inherent mechanism to temporarily slow down their development, similar to other mammals, even though this mechanism may not be utilized during pregnancy. This potential ability could be a vestige of the evolutionary process that humans no longer use. The ability to alter the timing of embryonic development has implications for in vitro fertilization (IVF), with the potential to increase the success rate of IVF by enhancing mTOR activity or triggering a dormant state to assess embryo health and improve implantation.
The discoveries by the research team provide unforeseen insights into the processes governing early human development, opening new avenues for enhancing reproductive health. The collaboration between the Max Planck Institute for Molecular Genetics and the IMBA highlights the importance of bringing together diverse expertise to tackle complex biological questions. Group leader Nicolas Rivron, funded by an ERC Consolidator Grant, emphasizes the significance of collaboration in advancing scientific understanding and indicates the potential for further research on how cells perceive signals during development.
Overall, the study sheds light on the potential for humans to control the timing of their development through the activation of a “pause button” mechanism similar to embryonic diapause. This discovery could have profound implications for reproductive medicine, particularly in enhancing IVF success rates and improving embryo health and implantation. The findings also underscore the importance of collaborations in advancing scientific knowledge and offer new possibilities for understanding cellular responses during the developmental process.