Blastoid (embryoid)

A blastoid is an embryoid,[1] a stem cell-based embryo model which, morphologically and transcriptionally, resembles blastocysts, resulting in it undergoing implantation on being introduced into the womb of a compatible female.[2] The first blastoids were created by the Nicolas Rivron laboratory[3][4] by combining mouse embryonic stem cells and mouse trophoblast stem cells. Upon in vitro development blastoids generate analogs of the primitive endoderm cells, thus comprising analogs of the three founding cell types of the conceptus (epiblast, trophoblast, primitive endoderm).[5] As compared to other stem cell-based embryo models (e.g. Gastruloids), blastoids model the pre-implantation stage and the integrated development of the whole conceptus including the embryo proper and the two extraembryonic tissues (trophectoderm and primitive endoderm). The blastoid is a model system for the study of mammalian development and disease.