Identification of genetic variation at murine casein loci by RFLP

Abstract

Genetic variation in the casein loci of Mus musculus (8 different strains) and Mus spretus was examined as restriction fragment length variants (RFLVs) using 5 restriction enzymes, BamHI, SftI, EcoRI, XbaI and HindIII. No variation was observed between the inbred strains of M. musculus. Between M. musculus and M. spretus variations in fragment length were observed at different casein loci, revealing restriction fragment length polymorphisms (RFLPs). All the 5 enzymes generated polymorphic fragments in -casein locus while and casein loci were polymorphic to four enzymes. The enzymes, HindIII and XbaI, yielded monomorphic fragments in and -casein loci, respectively. Three enzymes generated polymorphic fragments in -casein locus but only two yielded polymorphic fragments at -casein locus. Among the different casein loci, -casein locus was highly polymorphic while -casein locus exhibited least polymorphism. Thus, RFLVs suggest the occurrence of similar alleles at all the five casein loci viz., , , , and of the inbred strains of M. musculus and a bi-allelic existence was observed between M. musculus and M. spretus.