Study on Polymorphism of Three Functional Gene in Tibetan Yak and Holstein

Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP)and polymerase chain reaction-restriction fragment length polymorphism were tested within the prolactin,β-lactoglobin and κ-casein gene in Holstein and Tibetan yak.The results showed that there were large difference in prolactin gene and κ-casein gene of Tibetan yak and Holstein,but no D allele was found in β-lactoglobin gene.