Genetic Characteristics of the Exon 3 and 4 of β-LG in Buffalo

In this study,exon 3 and exon 4 plus their flanking segments of β-LG were amplified and sequenced in buffalo firstly.The polymorphisms of exon 4 of β-LG in 224 buffaloes belonging to 10 populations were investigated by means of PCR-RFLP and PCR-SSCP.Then we selected randomly 69 individuals from the 224 buffaloes to detect their polymorphisms of exon 3 of β-LG by PCR-SSCP and sequencing.The results showed that exon 3 and exon 4 of β-LG in both river and swamp buffalo were 74 bp and 111 bp long,respectively.The sequences of exon 3 and exon 4 of β-LG had 100% identity and monomorphism were observed for the buffalo populations studied.Compared with homologous sequence of bovine species,the sequences of exon 3 and exon 4 of β-LG are conservative,and the protein sequences in buffalo is the same with those coding by B allele in Bos taurus.There was no difference in the sequences of exon 3 and exon 4 of β-LG between both kind of buffalo,but they have significant difference in milking performance,this indicates that the exon 3 and exon 4 of β-LG have no direct effect on milk yield in buffalo.