Cytologic and genetic evidence of somatic segregation in mammals, birds, and fishes

The phenomenon of somatic segregation is defined herein as the formation of two new diploid cell types within the body of an ordinary monozygotic individual. In these new cell types, either two paternallyderived chromosomes or two maternallyderived ones constitute a homologous pair. By this mechanism, two kinds of cells homozygous for either one or the other allele emerge within the body of an individual heterozygous for a given genetic locus.