关键词: 牦牛, OXGR1基因, 多态性, HRM, 体尺性状

Abstract: The aim of this study was to examine the correlation between polymorphism of the Oxoglutarate receptor1 (OXGR1) and body measurement traits in yak (Bos grunniens). A total of 192 blood genomic DNA samples (age 4-8 years, male/castration) were randomly selected to construct the DNA pool. Direct DNA sequencing was used to detect potential polymorphic sites of the OXGR1. The results showed two SNPs (347(A/G) and 678 (G/A)) in Tianzhu White yak OXGR1， each with three kinds of genotype (AA, AG and GG) in high resolution melting curves (HRM), and the superior genotypes were GG and AA, respectively. The result of a χ²- test suggested that two SNPs met Hardy-Weinberg balance (P＞0.05) and have strong linkage disequilibrium between two loci (D’ > 0.75, R2 > 0.33) by SHESIS software. There was a moderate diversity located in two SNPs (0.25 < PIC < 0.5). The different genotypes of the two SNPs had significant differences in body length, body height, chest girth and tube girth (P＜0.05). The results of bioinformatics analysis revealed that the mutation of the 347 locus was a missense mutation, and the coded amino acid was translated from Asn to Ser, also the mRNA secondary structure, and secondary and tertiary structures of the protein were changed. Above all, the OXGR1 can be used in marker-assisted selection of yak, which could provide the basis for protection and development of yak genetic resources and breeding of new varieties in the future.

Key words: Body measurement traits, HRM, OXGR1, Polymorphism, Yak