New monkey embryo models—it’s getting complicated

Newswise — Li et al. report on the generation of cynomolgus monkey models of blastocyst-stage embryos (called “blastoids”) using naive cynomolgus embryonic stem cells. These blastoids recapitulate gastrulation in vitro and induce early pregnancy responses when transferred into cynomolgus monkey surrogates, prompting consideration of the policy implications for human blastoid research.