A MICROSATELLITE WITHIN THE BOVINE KAPPA-CASEIN GENE REVEALS A POLYMORPHISM CORRELATING STRONGLY WITH POLYMORPHISMS PREVIOUSLY DESCRIBED ATTHE PROTEIN AS WELL AS THE DNA LEVEL

The polymorphism of a (TA)(n)(CA)(n) repeat microsatellite present in the third intron of the bovine kappa-casein gene (CASK) has been inves tigated. The existence of six alleles differing only in the number of dinucleotide repeats has been established A total of 330 animals belon ging to nine different pure bred Bos taurus French breeds or to a cros s-bred Bos taurus x Bos indicus population (Creole) were genotyped. Th e distribution of the microsatellite alleles was examined and clear br eed differences were noted. Genotyping of animals by isoelectric focus ing (IEF) or restriction fragment length polymorphism (RFLP) (TaqI) wa s performed, in order to examine the relationship of the microsatellit e polymorphism to other previously described CASK polymorphisms, at th e protein and DNA levels. Strong correlation was seen, indicating that evolution of the various polymorphisms was not independent, and nine CASK haplotypes were observed.