Chromosomal localization of the ovine beta-casein gene by non-isotopic in situ hybridization and R-banding.

The ovine beta-casein gene (CNS2) has been mapped to a specific chromosome band using nonradioactive in situ hybridization and simultaneous fluorescent R-banding. The probe pTZ-E4 was a fragment of the ovine beta-casein gene inserted in the plasmid pTZ18R and labeled with biotin-11-dUTP. It hybridized to band q32 of ovine chromosome 4. The discrepancy between this result and the previous localization of this gene on cattle chromosome 6 may be explained by the very great similarity of the banding patterns of ovine and bovine chromosomes 4 and 6.