Single Nucleotide Polymorphism Of GH Gene And IGF-I Gene Associated With Production Performance In Jinghai Yellow Chicken

In this research, GH gene and IGF-I gene were selected as candidate genes affecting correlate traits in Jinghai yellow chicken. PCR-SSCP and DNA sequencing were used to detect the SNPs in candidate genes in order to research the correlation between different genotypes and the productive traits.1. According to the sequence of GH gene, six primers were designed and two mutations were found in primer P4, which generated three genotypes, AA, AB and BB. Sequencing results showed that mutation in GH gene sequence was located in exon 4 (C2338G and C2341T) and the mutations were synonymous mutation. Statistic results showed that the locus was in Hardy-Weinberg Equilibrium status (HWE) and was moderately polymorphic.2. According to the sequence of IGF-I gene, twelve primers were designed. Three genotypes were found in primer P11 of IGF-I gene, CC, CD and DD. Sequencing results showed that two A bases inserted in 5'promoter region of IGF-I gene. Statistic data showed that the locus was not in Hardy-Weinberg Equilibrium status (HWE) and was moderately polymorphic.3. In Jinghai male chicken, Statistic significance (P<0.05) was found within AA and AB in leg muscle weight, half eviscerated weight, eviscerated weight and live weight. The foot weight, glandular stomach weight and muscular stomach weight were highly different (P<0.01) between different genotypes. In females, the BB genotype had shorter age of first egg than AA genotype (P<0.05). The AA genotype had significant less total eggs than AB and BB genotypes in three hundred dates and sixty-six weeks. The spleen weight, liver weight and foot weight were significant different (P<0.05) between different genotypes in females, among which BB genotype is higher than AA genotypes.4. Statistic results showed that genotype AA brought the positive direct contribute percentage (CP) to the live weight, spleen weight, liver weight, head weight, foot weight, glandular stomach weight, muscular stomach weight, leg muscle weight half eviscerated weight and eviscerated weight, which were above 8% in males. The main effect index (MEI) of live weight, leg muscle weight half eviscerated weight and eviscerated weight were over 10% in males. AA brought the negative direct contribute percentage contribute percentage to eggs (300d), spleen weight and liver weight in females. The MEI of eggs (300d), spleen weight and liver weight were over 10%. It implied that the GH gene could be a genetic locus or linked to a major gene greatly affecting the reproduction and carcass traits in Jinghai yellow chicken.5. Statistic results showed that the live weight was significant different (P<0.05) between CC and DD genotype in males. The foot weight, breast muscular weight, half eviscerated weight and eviscerated weight were highly different (P<0.01) between CC and DD genotype in males. In females, the foot weight was highly significant different (P<0.01) between CC and DD genotype. The breast muscular weight and percentage of breast were significant different (P<0.05) between DD and CD genotype in females,6. Statistic results showed that genotype DD brought the negative direct CP to the live weight, and breast muscular weight, which were above 8% in males. The MEI of live weight and breast muscular weight were over 11% in males. Genotype DD brought the negative direct CP to foot weight in females, while brought the positive direct CP to breast muscular weight and percentage of breast muscular. The MEI of foot weight, breast muscular weight and percentage of breast muscular were over 9%. It implied that the IGF-I gene could be a genetic locus or linked to a major gene greatly affecting the carcass traits in Jinghai yellow chicken.7. The combinatorial effects analyses of different genotypes amplified by primer 4 and primer 11 showed that: the two polymorphism sites AA/CD genotype has combined effect on the live weight and breast muscular weight, while AA/CD genotype has combined effect on the live weight, breast muscular weight and leg muscular weight in male Jinghai yellow chicken. In female Jinghai yellow chicken, AA/CC genotype has combined effect on the egg laying number of 66 weeks and foot weight.