The Analysis Of VDR Polymorphisms Of Bovine And Their Association With Growth Traits

The VDR gene encodes the nuclear hormone receptor for vitamin D3which plays acrucial role in calcium related metabolism and calcium homeostasis. In human, VDRpolymorphisms are associated with several metabolisms such as type1diabetes mellitus andtype II vitamin D-resistant rickets.Hence，we took VDR gene as a candidate gene formarker-assisted selection and management in beef breeding practice in this study.We detected the genetic variations of VDR gene employing DNA pool sequencing andCRS-PCR-RFLP techniques within1166individuals from five different cattle populations（Jiaxian red cattle, Nanyang cattle, Qinchuan cattle, Luxi cattle and Caoyuan red cattle）. Theassociations between the four mutations of the gene with growth traits were analyzed inJiaxian red, Nanyang,and Qinchuan breeds. The results showed as follows:The varations of ten locis （P1-P10） including VDR gene ten exons were studied. In theseten locis, we detected4mutations （NC₀07303.5: g.45515T>C,53558C>A，53855C>T,55352C>T）. Moreover, the mutations g.45515T>C, g.53558C>A, g.53855C>T located inexon7, exon8and exon9, separately; while the mutation g.55352C>T was located in intron9.Two of them revealed two synonymous mutations, g.45515T>C mutation: TAT （Tyr）> TAC（Tyr）; g.53855C>T mutation: AAC （Phe）>AAT（Phe）. One is missence mutation: g.53558C>A mutation: CCG （Pro）> CAG （Gln）.In g.45515T>C mutation, we detected three genotypes （TT、TC and CC）, and thefrequencies of CT and TT were:0.393-0.707and0.020-0.232. In g.53558C>A, we detectedtwo genotypes （CC andCA）, the frequency of the CA was:0.036-0.254. In the g.53855C>Tmutation, we detected two genotypes （CC and CT）, and the frequency of the CT was:0.058-0.138. In g.55352C>T mutation, we detected three genotypes （CC、CT and TT）, thegenotype frequencies of the CT and TT were:0.340-0.550and0.235-0.349. At45515T>Cloci, all the five breeds belonged to morderate genetic diversity. The linkage disequilibriumanalysis showed that all of the four locus had no linkage.among all the five breeds. In g.45515T>C mutation, three genotypes had significant association with body height inJiaxian population（P<0.05）; different genotypes had significant association with body weight,body height, body length, hucklebone width,heart girth and average daily gain in Nanyangpopulation aged6months（P<0.05or P<0.01）. In53558C>A loci, different genotypes hadsignificant association with body height and body length in Jiaixian population（P<0.05）;they also have strong association with body height, body length, heart girth and hucklebonewidth in Nanyang population（P<0.05or P<0.01）. In g.53855C>T mutation, differentgenotypes had significant association with body height,body length, heart girth, hucklebonewidth, body length and rump length in Qinchuan population（P<0.05or P<0.01）; they also hadhave strong association with body weight and average daily gain in Nanyang population aged18and24months（P<0.05or P<0.01）. In g.55352C>T mutation, different genotypes hadsignificant association with heart girth, body weight, height at hip cross and waist corner widthin Qinchuan population（P<0.05）; they also have strong association with body height, bodylength, body weight, rump length and hucklebone width in Jiaxian population and hadsignificant association with body height, body wight, heart girth and hucklebone width inNanyang population（P<0.05or P<0.01）.Besides, we predict and analysis the function and structure of the VDR gene byemploying bioinformatic tools which will lay a foundation for the future study on verifting itsfunction in vivo.