Molecular genetic characterization of ovine beta-lactoglobulin C allele and detection by PCR-RFLP

Ovine beta-Lactoglobulin C allele (LGB*C), that has so far been detected on ly in Merino breeds, was characterized by cloning and sequencing of exon V, intron V and parts of exon VI of the gene. Two G/A transitions were found in positions 4626 and 4750 of ovine LGB*C compared with the published seque nce. The first mutation corresponds to the amino acid substitution in posit ion 148 (Arg/Gln), causes the loss of an MspI site and creates an AluI site in LGB*C. The second mutation creates an MspI site in intron V of LGB*C. T herefore a PCR-RFLP typing procedure using MspI was developed for simultane ous detection of both mutations. The present results indicate, that the mut ations are linked and are both specific for LGB*C. The test described here provides the possibility of lactation-independent typing of LGB*C and furth er studies may evaluate the breed distribution of this rare allele.