Embryonic stem-like cells derived from in vitro produced bovine blastocysts

the aim of this work was to study the derivation of bovine embryonic stem-like (es-like) cells from the inner cell mass (icm) of in vitro produced blastocysts. the icms were mechanically isolated and six out of seventeen (35%) icms could attach to a monolayer of murine embryonic fibroblasts (mef). ten days after, primary outgrowths were mechanically dissected into several small clumps and transferred to a new mef layer. cells were further propagated and passaged by physical dissociation over a 60 days period. the pluripotency of the bovine es-like cells was confirmed by rt-pcr of oct-4 and stat-3 gene markers. the colonies were weakly stained for alkaline phosphatase and the mesoderm and endoderm differentiation gene markers such as gata-4 and flk-1, respectively, were not expressed. embryoid bodies were spontaneously formed at the seventh passage. results showed that bovine es-like cells could be obtained and passaged by mechanical procedures from the fresh in vitro produced blastocysts.