Somatic cell mapping of the bovine somatostatin gene

DNAs from cow-hamster and cow-mouse hybrid somatic cells segregating cow chromosomes have been analyzed by Southern blotting and hybridization with a bovine somatostatin probe. The somatostatin gene (SST) was found to segregate concordantly with superoxide dismutase-1 (SOD1) and α-crystallin (CRYA1), representing cattle syntenic group U10. Because homologues of these three genes also have been mapped in mice and humans, a comparison of the gene maps of the three mammalian species gives some insight into the chromosomal rearrangements that have accompanied their evolution. We propose that the bovine chromosome carrying U10 is an ancestral chromosome that has given rise to human chromosome 21 and mouse chromosome 16, with each requiring a minimum of one rearrangement.