It seems like you made edits to a development site, that you intended to make to the production site. You're edits are pasted here:
Wichterle, et al.: They grafted the EBs into the embryos at "stage 15-17" of the embryos' development. At that stage, how differentiated are the embryo's endogenous motor neurons or motor neuron precursors? Are they implanting the EBs next to pluripotent stem cells, rostral neural, caudal neural, or fully differentiated motor neuron cells? If they had implanted the EBs later during development, would the recipients have incorporated the grafted cells so successfully? Implanting EBs into healthy embryos that are still developing is not nearly as impressive or as clinically useful as implanting EBs into adults that need new tissue.
Chambers, et al.: What trigger tells the Cre when to excise the Nanog gene? Where does Cre come from and for what purpose did it evolve? I am a fan of figure 6.D, which shows the reader that these chimeras can grow up to be happy, healthy, and normal looking adult mice. I think they should have included a photo of a negative control mouse too, just to add credibility.