Genotyping of kappa-casein gene in Egyptian buffalo bulls

The present work is undertaken mainly for genotyping of kappa-casein gene in buffalo bulls. DNA was extracted from the frozen semen of nine buffalo bulls used in artificial insemination in addition to 40 blood samples of male buffalo calves for identification and genotyping of kappa-casein gene by PCR-RFLP assay. Different restriction endonucleases, including HindIII, HinfI and Taq1 were used. The PCR product of the primer specific for K2 and KY gives the specific band at size 379 and 280 bp respectively. Digestion of 379 bp fragment K2 by restriction endonuclease HindIII generated two fragments of 156 and 223 bp. For fragment 280 bp kappa-casein KY, the above mentioned endonuclease generated two fragments of 180 and 100 bp. Digestion of the 379 bp PCR product with HinfI resulted two restriction fragments of 288 and 91 bp. On the other hand, the amplified DNA (379 bp) from buffalo remained undigested by Taq1 restriction enzyme.In conclusion, the PCR-RFLP technique demonstrated that bulls were monomorphic for the kappa-casein gene; they possess only allele B in homozygosis form.