Research On Kap13.1 And Igf-1 Gene Genetic Variation And Association With Economic Traits Of Goat Breeds In Xinjiang

The PCR-SSCP, PCR-RFLP techniques, DNA sequencing, DNA sequence analysis and bioinformatics methods, were applied to analyze and scan the genetic variations of candidate gene and their association with economic traits in 776 goats, which comprised of three cashmere breeds, (namely, Xinjiang goat, Nanjiang cashmere goat and Bogeda cashmere goat). The 2 candidate genes included KAP13.1 and IGF-1 gene. The cashmere economic traits comprised of cashmere yield, cashmere thickness, weight, cashmere fineness. The association between genetic variations and cashmere economic traits were analyzed with two candidate genes. These。will benefit for the protection, development and application of goat genetic resource, application of DNA marker related to cashmere economic traits on marker-assist-selection (MAS). The important results were in the followings:1. Genetic variation of HS-KAP gene and their association between economic traitsOne HS-KAP gene of KAP gene family were researched in this experiment, namely, KAP13.1. There were 5 SNP in KAP13.1 gene, namely, c.67 G> A, c.115 T> C, c.124 C> T, c.186 T> G and c.213 C>G. The mutations of c.67 G> A,c.115 T>C,c.124 C> T resulted in synonymous mutation, and c.186 T>G, c.213 C> G resulted in p.48 Leu> Arg, p.57 Thr> Ser missense mutation. The two transversion SNPs that c.186 T> G was complete linkage and resulted in PvuⅡpolymorphism in KAP13.1 gene, which suggest there was polymorphism in KAP13.1 gene.The polymorphisms were detected in Xinjiang goat, Nanjiang cashmere goat and Bogeda cashmere goat, while the X2-test showed that the genotype distributions in these three goat breeds were not in agreement with Hardy-Weinberg equilibrium (P>0.05). Moreover five mutations were described at KAP13.1 locus for the first time. This may be linkage to the breed characterization of Xinjiang goat and it stabilization of genetic. Therefore the polymorphism was considered as the breed and area characterization of Nanjiang cashmere goat and Bogeda cashmere goat at KAP13.1 locus. This maybe caused by the breeding program of this two cashmere goat breeds. Chi-Square analysis of genotype and allele frequencies distribution at this polymorphic loci of KAP13.1 gene showed that there were significantly different among three goat breeds (P<0.01). According to the previous researching result as well as the result of my experiment, it was presumed that KAP genes had more variation in different breeds, which resulted in the polymorphism of cashmere traits. The GLM analysis result in polymophic locus and cashmere traits and weight among three goat breeds showed that different genotypes of KAP13.1 gene significantly affect on detected cashmere thickness trait and weight in Nanjiang cashmere goat. Therefore, KAP13.1gene was considered as the candidate gene of cashmere thickness trait in Nanjiang cashmere goat.2. Genetic variation of IGF-1 gene and their association between economic traits2 SNP were detected in four locus of IGF-1, in which 2 SNP were not reported in other breeds and 2 SNP were reported at the first time. Two SNP of c.1617 G> A and c.1620 C> T were resulted in synonymous mutation.Gene heterozygosity, effective allele numbers and PIC of IGF1 gene in three goat breeds between 0.30 and 0.5 were at median polymorphic level. Chi-Square analysis of genotype and allelic among three goat breeds show significantly different(P<0.01). The polymorphic locus of IGFI gene significantly affect on cashmere fineness traits and weight of Nanjiang cashmere goat (P<0.05), didn't significantly in other cashmere traits. The polymorphic locus of IGF1 gene significantly affect on Nanjiang cashmere goat fineness traits show genotype AA cashmere fineness traits was lower than genotype AB (P<0.05), genotype AC weight trait was significantly more than genotype BB (P<0.05). P1 locus was considered as the candidate SNP of fineness trait. The main reason may be the mutation effected on IGF-1, which resulted in fineness traits.