Regeneration of endoderm from primitive ectoderm in the mouse embryo: fact or artifact?
The publishers regret that there is an error on page 323 of this article. The last paragraph should read as follows:
The fact that individual 5th day primitive ectoderm cells can give rise to both somatic cells and functional gametes (Gardner, 1978a) argues that they retain genomic totipotency. Nevertheless, results obtained in the present study and in earlier blastocyst injection experiments (Gardner & Rossant, 1979; Gardner, 1982) do not support the conclusion that these cells remain undetermined until 2 days or so after implantation. Rather, they suggest that both primitive ectoderm and primitive endoderm cells become restricted to mutually exclusive lineages more or less synchronously, some time between and days post coitum. So far, extraembryonic-endoderm-like cells have only been obtained unequivo-cally from primitive ectoderm following its exposure to conditions of terato-carcinogenesis (Graham, 1977). In view of...