[Hematologic chimerism in cattle twins]

A cytogenetic examination of a cow and its offsprings, obtained by pair transplantations of the embryos was carried out. The fragile X and the heteromorphism of the chromosomes XX of this cow and some of its offsprings were revealed. The variability of the hematological chimerism of the pair transplanted embryos was observed. The immigrated cells were, as a rule, distinguished by the comparatively low frequencies of the metaphases with the nearly located chromosomes XX. The heterogeneity of the stem blood cells of the embryos for some traits, and for the ability to migrate in the blood of the twin is under discussion.