Abstract:
【Objective】 To clarify the association between xanthine dehydrogenase gene(
XDH) single-nucleotide polymorphism(SNP) and reproductive traits of Kele pigs, and provide theoretical basis for accelerating the breeding process of Kele pigs. 【Method】 Eighty-seven healthy multiparous Kele sows were selected as the study subjects. The SNP loci of
XDH gene were screened by Sanger sequencing method. The association between SNP loci and reproductive shape indexes(number of live piglets, litter weight at birth, average birth weight, number of weaned piglets, weaning litter weight and average weaning weight) of Kele sows was analyzed by general linear model(GLM) in SPSS 22.0. Bioinformatics analysis was carried out by RNAfold web server, ExPASy-ProtParam, NovoPro and SWISS-MODEL online softwares. 【Result】 Twelve SNPs loci were screened in the
XDH gene of Kele pigs, which were g. 108047658C>G and g.108047680C>A loci in intron 33,g.108048009C>T,g.108048044T>C,g.108048046T>C,g.108048047C>T,g.108048054C>T g.108048153A>T, g.108048208A>G, g.108048212T>C and g.108048242C>T loci in intron 34, and g.108047915G>A site in exon 34. There are 3 genotypes in all 12 SNPs loci, which were moderately polymorphic loci(0.25<PIC<0.50).The genotype distributions of the loci g. 108048047C>T, g. 108048208A>G, g. 108048242C>T, g. 108048044T>C, g.108048046T>C and g.108048212T>C were consistent with Hardy-Weinberg equilibrium(
PHWE>0.05), the genotype distributions of the remaining 6 SNPs loci deviated significantly from Hardy-Weinberg equilibrium(
PHWE<0.05). There was no strong linkage disequilibrium among the other SNPs loci except for the strong linkage disequilibrium between loci g.108047658C>G and g.108047680C>A,between loci g.108048044T>C and g.108048046T>C,between loci g.108048046T>C and g.108048047C>T. g.108047658C>G and g.108047915G>A loci had significant effects on the number of live piglets produced by Kele pigs(
P<0.05, the same below), the number of live offspring of individuals with genotype CG at locus g.108047658C>G was significantly higher than that of individuals with genotype GG, and the number of live offspring of individuals with genotype AG at locus g.108047915G>A was significantly higher than that of individuals with genotype AA. Mutation at locus g.108047915G>A changed the mRNA secondary structure of
XDH gene, and the minimum free energy increased from-1508.90 kcal/mol to-1507.80 kcal/mol. Mutation of allele G of
XDH gene also changed the molecular formula, relative molecular weight, theoretical isoelectric point(p I), instability coefficient and protein higher structure of
XDH gene. 【Conclusion】 g.108047658C>G locus in intron 33 and g.108047915G>A locus in exon 34 of
XDH gene in Kele pigs has significant effects on the number of live piglets, which can be used as potential molecular auxiliary markers for improving reproductive traits of Kele pigs.