Reacción a "Reactions: First chimeric monkey born from embryonic stem cell lines"

This is a very good and important paper. It shows in primates what we know in rodents: that naive pluripotent stem cells are capable of integrating into developing blastocysts, and then [once implanted in] the uterus, can contribute to all tissues in developing a viable monkey embryo. The results of this study are solid. 

For years, scientists didn't know if naive pluripotent cells are a rodent-specific phenomenon. In 2013, our group (Gafni et al. Nature 2013) showed that they exist in humans, and since then this has become an active area of research where multiple types of naive stem cells have been derived in humans and in primates. Of course, chimera experiments cannot and must not be done with human embryos (this would be unethical and illegal), so it is important to demonstrate this proof of concept in monkeys. 

This study may contribute to easier and better making of mutant monkeys, just like biologists have been doing for years with mice. Of course, working with non-human primates is slower and much harder than with rodents, but it is important. As we have recently showed also, naive human stem cells [are capable of making] complete human embryo models (Oldak et al. Nature 2023), thus this might be relevant also to monkeys.