Development of Mouse Embryos in vivo after Cultivation from Two-cell Ova to Blastocysts in vitro

Abstract

THE purpose of this communication is to describe the successful development of mouse embryos within recipient foster mothers after previous cultivation in vitro from the two-cell to the blastocyst stage. Prior to this, three reports have been made of successful foetal development of embryos cultured longer than 24 h, but these were done under more restrictive conditions. McLaren and Biggers¹ cultivated embryos from the 8- to 16-cell stage to blastocysts in vitro and transferred them to pregnant foster mothers. Twenty per cent of the transferred blastocysts developed into foetuses and two animals were successfully reared to adults. Tarkowski², in his work on mouse chimeras, cultured the fused 8-celled embryos to blastocysts and obtained living young after development in recipient foster mothers. Biggers, Gwatkin and Brinster³ cultured mouse zygotes to blastocysts in organ cultures of Fallopian tubes and obtained foetal development after transfer to foster mothers.