C-band polymorphisms in exotic inbred strains of mice: a method for mapping centromeric ends of chromosomes.

The major satellite DNA of Mus musculus appears as a pericentromeric heterochromatin block in all chromosomes but the Y. While C-banding readily reveals the presence of this heterochromatin block, there is considerable polymorphism in C-band size among the chromosomes and among different subspecies. We have studied the distribution of C-band size differences in the chromosomes of 15 exotic inbred laboratory strains and substrains derived from wild populations of different subspecies of M. musculus. The variation in C-band size among these inbred strains can serve as a useful codominant cytological marker for estimating recombinational distances between the centromere and proximal genes in linkage crosses.