Study On The Polymorphism Of Several Genes And Its Relationship With Growth And Development Traits In Nanyang Cattle

PCR-SSCP and PCR-RFLP technologies were applied to detect the polymorphisms of DGAT1 gene exon 8, intron 3, 6 and 7 of DGAT2 gene, exon 2 of IGF2 gene, IGFBP-3 gene and MEF2 gene in Nanyang cattle. The associations between these polymorphisms and growth and development traits were analyzed using the SAS general linear model (GLM). Results were obtained as follows:1. The K232A replacement of DGAT1 gene exon 8 was first studied in Nanyang cattle by this experiment. Two SSCP alleles (named allele K and allele A) of DGAT1 gene exon 8 were detected. The frequencies of allele K and A were 0.33, 0.67 respectively. This locus is at Hardy-Weinberg equilibration (p>0.05)in Nanyang cattle.2. The list square means linear general model analysis results showed: significant association between genotypes and withers height at 6 month age, heart girth at 18 and 24 month age, body weight at 24 month age and Hucklebone width at 24 month age(P<0.05). And the values of those traits of individuals with genotype AK are higher than that with genotype KK.3. The single marker regress analyze showed that this locus had significant addictive effect on withers height at 6 month age, heart girth at 18 and 24 month age, Hucklebone width at 12 month age and body weight at 24 month age.4. Four SSCP aelles and seven genotypes in DGAT2 gene intron 3 were detected out. The five aelles were named A, B, C and D and their frequencies were 0.261, 0.549, 0.174 and 0.016, separately. Analyzing the relationship between genotypes and growth and development traits showed: the body weight of individuals with genotype AD was significantly lower than other genotypes at 18 and 24 month age; the wither height of individuals with genotype AD was significantly lower than other genotypes at 6, 18 and 24 month age; the body length of individuals with genotype AD was significantly lower than individuals with genotype CC and AA at 18 and 24 month age; the heart girth of individuals with genotype AD was significantly lower than individuals with genotype CC and AA at 18 and 24 month age; the heart girth of individuals with genotype AD was significantly lower than individuals with genotype CC and AA at 18 and 24 month age; the Hucklebone width of individuals with genotype AD was...