Study On The Genetic Polymorphism Of Bovine LXRα And FIAF Gene And Its Association With Growth Traits In Six Cattle Populations

DNA sequencing, PCR-SSCP and PCR-RFLP techniques were used to detect the genetic polymorphism of the LXRαand FIAF gene in Luxi cattle, Jiaxian red cattle, Bohai black cattle, Qinchuan cattle, Nanyang cattle and Qinghai yak, a total number of 373, and association analysis was carried out to evaluate the effect of genotypes of the candidate genes on growth traits in Luxi cattle and Jiaxian red cattle. The results were as follow:1. The genetic polymorphism of bovine LXRαgenePCR-SSCP, PCR-RFLP and DNA sequencing techniques were used to detect the genetic polymorphism of CDS for bovine LXRαgene in six populations, and 4 SNPs were discovered: 1028T>C at LXRα-I1, 1514T>C at LXRα-E2, 2929G>A at LXRα-E4 and 3493T>C at LXRα-I5 locus(ref. NC₀07313). The 1514T>C SNP was a silent mutation of Asp and 2929G>A SNP was a silent mutation of Pro. The 1028T>C and 1514T>C SNPs were midrange polymorphism in five cattle populations and low polymorphism for Qinghai yak, while 2929G>A and 3493T>C SNPs were both low polymorphism for the six populations.2. The association analysis between the genetic polymorphism of bovine LXRαgene and the growth traitsThe correlation analysis between the genetic polymorphism of bovine LXRαgene and the body height, body weight, body length and so on, discovered that: at LXRα-I1 locus, CC genotype had greater body height (P<0.05), body length (P<0.01) than TC genotype for Luxi cattle; there was no significant differences between different genotypes and the growth traits for Jiaxian red cattle (P>0.05). At LXRα-E2 locus, TT genotype had greater body height (P<0.05) than TC genotype for Luxi cattle; TT genotype had greater body height, body length and hipbone width (P<0.01), body weight, chest circumference and abdominal circumference (P<0.05) than TC genotype for Jiaxian red cattle. At LXRα-E4 locus, GG genotype had greater hip height (P<0.05) than GA genotype for Luxi cattle and no significant difference for Jiaxian red cattle. At LXRα-I5 locus, TT genotype had higher growth traits except hip width than CC genotype for Luxi cattle, requiring further research and no significant difference for Jiaxian red cattle.3. The genetic polymorphism of bovine FIAF genePCR-SSCP and DNA sequencing techniques were used to detect the genetic polymorphism of CDS for bovine FIAF gene in six populations, and 3 SNPs were discovered: 1422T>C at FIAF-E3 locus was a missense mutation of Leu> Pro; 4899C>T at FIAF-E5 locus was a silent mutation of Ser; 5095T>A at LXRα-E6 locus was a silent mutation of Arg (ref. NC₀07305). The 1422 T>C SNP was midrange polymorphism only for Luxi cattle and Qinchuan cattle; 4899 C>T and 5095 T>A SNPs were low polymorphism in six populations.4. The association analysis between the genetic polymorphism of bovine FIAF gene and the growth traitsThe correlation analysis between the genetic polymorphism of bovine FIAF gene and body height, body weight, body length and so on. At FIAF-E3 locus, TT genotype had higher body length, hipbone width and hip weight (P<0.05) than CC genotype for Luxi cattle and no significant difference for Jiaxian red cattle. At FIAF-E5 and FIAF-E6 locus, there was no significant difference between genotypes and the growth traits for Luxi and Jiaxian cattle.