Molecular characterization of a mouse Y chromosomal repetitive sequence amplified in distantly related species in the genus Mus.

This report describes a 1.1 kb long mouse Y chromosomal sequence designated 142-4. It has a 42% GC content and is rich in short direct and inverted repeats. 142-4 related sequences are repeated about 200 times in the Mus musculus Y chromosome and their distribution was visualized by in situ hybridization. 142-4 detected a restriction fragment length polymorphism that differentiated between the M. m. musculus type and the M. m. domesticus type Y chromosome. Southern blot analysis of DNAs isolated from a panel of mouse species showed that 142-4 related sequences were amplified in the Y chromosomes of M. minutoides, M. musculus, M. saxicola, M. spicilegus, and M. spretus but not in those of M. caroli, M. cookii, and M. pahari. These results suggest that 142-4 related sequences are evolutionarily unstable and their accumulation patterns do not correlate with the known phylogenetic relationships of mouse species in the genus Mus.