| Fat mass and obesity associated gene(FTO) is a member of the non-heme dioxygenase superfamily.It influences other metabolic related genes by its nucleic acid demethylation activity and joins in the important biological process regulation such as energy metabolism and fat metabolism. FTO is a important gene which is associated with production traits in animals. In this research, the single nucleotide polymorphisms (SNPs) of FTO gene were detected by Sequencing technology in241rabbits including Ira rabbits, Champagne rabbits, Tianfu black rabbits. The correlation between different FTO gene diplotype and growth traits and carcass traits were analyzed. FTO gene could be a candidate gene of molecular genetic breeding in rabbits.The results were as follows:Eight polymorphisms were identified in FTO gene from exon3to exon9, their locations were in exon3, exon6, exon8, and one polymorphism was identified in intron3. The distribution of genotype and genotype frequency were calculated by statistical methods on on4SNPs (SNP1-SNP4) in exon3and1SNP (SNP5) in intron3. The analysis suggests that SNP1:AC (0.0217,0.0098,0.0213), CC (0.9783,0.9902,0.9787); SNP2: AA (0.7609,0.7157,0.9574), AG(0.2065,0.2843,0.0426), GG(0.0326,0,0); SNP3: AG(0.0326,0.1176,0.0213), GG(0.9674,0.8824,0.9787); SNP4:CC(0.1304,0,0.2553), TT(0.4457,0.5294,0.2979), CT(0.4239,0.4706,0.4467); SNP5:CC(0.7609,0.7157,0.9574), TT(0.0326,0,0), CT(0.2065,0.2843,0.0426).SNP2and SNP3were missense mutations which caused the change of amino acids:Lysine (K) into argining (R), alanine (A) into threonine (T); the others were synonymous mutations.Genetic polymorphisms analysis showed that four polymorphic sites (SNP1, SNP2, SNP3, SNP5) had low Polymorphism Infromation Content (PIC<0.25), and SNP4site had intermediate Polymorphism Infromation Content (0.25<PIC<0.5). The Chi-square test indicated a significant deviation from the Hardy-Weinberg equilibrium (P<0.05) in the SNP4site of Ira rabbits, but the rest of SNPs sites were in Hardy-Weinberg equilibrium (P>0.05).The5SNP sites constituted6haplotypes (H1,CAGTC; H2,CAGCC; H3,CAATC; H4, CGGTT; H5,AAGTC; H6,AGGTT), H1and H2were the dominant haplotypes, which haplotype frequency were accounting for52.49%and32.37%;6haplotypes formed10diploytpes(H1H1, H1H2, H1H3, H1H4, H1H6, H2H2, H2H3, H2H4, H2H5, H4H4), H1H2was the dominant diploytpes which frequency was accounting for31.94%. The genetic effect analysis of FTO gene diploytpe and production traits in three rabbit breeds showed:FTO gene diploytpe had significant gentic effects on28-day-weight,35-day-weight,70-day-weight,84-day-weight and daily gain after weaning. Diplotype H4H4had the highest28-day-weight,35-day-weight,70-day-weight and84-day-weight, and such diplotype had a positive effect on the growth traits. FTO gene diploytpe had significant gentic effects on eviscerated weight, semi-eviscerated weight, semi-eviscerate slaughter percentage and eviscerated slaughter percentage. Diplotype H4H4had the highest least squares means in these four carcass traits, thus it had a positive effect on the carcass traits. FTO gene played an important role in the growth and development of rabbit. It could be a candidate modifier gene that affect or control the growth traits and carcass traits. FTO gene diploytpe had no significant gentic effects on cooked percentage, intramuscular fat content of longissimus muscle and intramuscular fat content of hind leg muscle, but had significant gentic effects on pH of longissimus muscle, colour (L, a, b) of longissimus muscle and hind leg muscle. The further study is necessary for FTO gene that influence the meat quality traits of rabbits as a candidate modifier gene. |
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