The Guinea Pig: A New Model for Human Preimplantation Development

Preimplantation development is an important window of human embryogenesis. During this time, the initial lineages are formed which largely govern embryo competence, implantation, and ultimately the developmental potential of the fetus. Ethical constraints and limitations surrounding human embryos research often necessitates the use of a model system. We now identify the guinea pig as a promising small animal model, which closely recapitulates early human embryogenesis in terms of the timing of compaction, early-, mid-, and late-blastocyst formation and implantation. We also observe conserved spatio-temporal expression of key lineage markers, roles of both Hippo and MEK-ERK signaling and an incomplete X-Chromosome inactivation. Further, our multi-species analysis highlights the spatio-temporal expression of conserved and divergent genes during preimplantation development. The guinea pig serves as an exciting new model which will enhance developmental and pluripotency research and can be leveraged to better understand the longer term impact of early exposures on offspring outcomes.