Taihang Chicken Agouti Gene And Its Correlation With Some Production Performance Analysis

Agouti gene plays an important role in the synthesis and distribution of coat color indomestic animals. A total of71complete coding sequences (CDS) of Agouti gene(belonging to15species) were analyzed and the promoter region of chicken Agouti genewas predicted by bioinformatics analysis, slaughter performance relationship of Taihangchicken and the Roman layers in different generations were analyzed by bio-statisticalmethods, using direct sequencing of PCR products, SNP screening and genetic diversityanalysis of the Agouti gene3’UTR (the Taihang chicken of partridge strain, black strainand white strain, Roman layers, Highland brown chicken) and exon4(Taihang chicken,Lingshan chicken×Taihang chicken) were carried out, combining the SNPs genotypefrequencies and allele frequency of the haplotype analysis method, relationship betweenAgouti gene SNPs and chicken feather color, body size indicators and slaughterperformance were analysed, thus to explore the impact of the Agouti gene mutation togenetic and production performance of the Taihang chicken feather color, and provide areference for the the Taihang chicken new line breeding.The result indicated that the averaged net genetic distance (Da) and the averagednucleotide divergence (Dxy) among species were0.2256and0.2145, respectively. Thegreatest genetic diversity of Agouti gene was existed in Peromyscus maniculatus and Lamapacos. From result of Da and Dxy, the genetic relationship between mammalian and Daniorerio was closer than that between birds and Danio rerio. The predicted promoter region ofchicken Agouti gene was from2600bp to3000bp upstream of start codon.A total of9variations of chicken Agouti gene3’UTR were found, which2of themwere (g.1554712T>C and g.1554767C>G) only in Taihang chicken, correlation of differentfeather colors, site and production performance were analysed. The results showed that allof the variations except for g.1554806C>A were at Hardy-Weinberg equilibrium inpartridge and white strain of Taihang chicken, but deviated in black strain. A total of6haplotypes were sorted from9variation sites. HAP1(AACATGATC) and HAP2(CCTGCAATC) were two main haplotypes, from which other haplotypes differentiated.The complete linkage of6variation sites (g.1554591C>A, g.1554621C>A, g.1554693T>C,g.1554694G>A, g.1554788C>T and g.1554798A>G) was found. There was no significantdifference of genotype frequency among different color strains of Taihang chicken (p>0.05), but significant difference existed among Roman layers, Hy-line brown and Taihang chicken at site1(p <0.01) and at site2(p <0.05) except among Roman layers, Hy-linebrown and Taihang chicken (white) at site2. The correlation analysis showed that thecomplete linkage site has significant relationship with live body weight and measurements(body slope length, shank length, pelvis width, breast angel, fossil bone length, and shankcircumference). The significant relationship between the complete linkage site and thecarcass performances (percentage of breast muscle and wing) was also detected.The variation of exon4of Agouti gene were investigated in Taihang chicken (F0) andits hybrid generation (F1, Lingshan xiang chicken×Taihang chicken). A total of10SNPswere found in F0, of which8in F1. All of the variation sites were at Hardy-Weinbergdisequilibrium in F0except for g.1554779T>G and all of them were at Hardy-Weinbergequilibrium in F1. Two complete linkage sites (g.1554892G>A and g.1554994T>G) werefound in populations. There were significant difference of genotype frequency between F0and F1except for g.1554779T>G. There were significant relationship of g.1554787T>Cand g.1554797G>A with measurements breast depth and shank circumference,g.1554891T>C with pelvis width and shank circumference, g.1554892G>A with pelviswidth, and g.1554964T>G with breast depth and shank length. The significant relationshipbetween all SNPs and dressed percentage were also detected except for g.1554779T>G.