[Chimeric drift in blood erythrocyte population in BALB/c----C57BL/10 and BALB----B10.D2 mice]

Genotypic composition of the erythrocyte population of peripheral blood in 16 aggregation chimeras: BALB/c (H-2dd)----C57BL/10(H-2bb) and BALB/c(H-2dd)----B10.D2(H-2dd) was studied during 10 months. The proportion of cells of parental components was defined visually in the coat and by electrophoresis of allozyme variants at the Gpi-1 locus in blood. The similar increase of blood cells percentage was observed in blood of both types of chimeras with age. In chimeras the skin grafts of both parental types survive. Chimeric drift is not caused by H-2 haplotypes differences between cells of two strains or disturbance of immunological tolerance in the chimeric mice. We propose that chimeric drift results from interaction of hemopoietic cells of different strains in early stages of hemopoiesis.