Genome-wide association analysis for exterior traits in Tsarskoye Selo chicken breed

To date, poultry industry, which is an indispensable supplier of animal protein, almost entirely depends on foreign commercial crosses. In this regard special attention should be paid to local poultry breeding and available genetic resources. Exterior assessment in an important part of selection, as animal’s appearance is an indication of health, breed affiliation, predisposition to productive use and adaptability to housing conditions. However, the selection rate depends on both phenotypic and genetic data. Recently special attention has been paid to GWAS studies - a genome-wide association search that identifies genome regions presumably responsible for certain traits’ expression. The aim of the study was to identify genetic associations with exterior traits in the Tsarskoye Selo chicken breed. For this purpose, we performed exterior assessment of the birds (n=96), blood sampling and DNA extraction, as well as genome-wide genotyping using Illumina Chicken 60K SNP iSelectBeadChip (Illumina Inc., USA). GWAS analysis and annotation of candidate genes were performed based on genome data obtained. As a result, 6 suggestive SNPs associated with chest girth, tibia length, tarsus length, and chest angle were obtained. Most genes in the identified loci are involved in processes of bone formation and bone homeostasis, which indirectly regulate the biological growth potential of an individual. The identified candidate genes can be recommended for use in marker-assisted selection of Tsarskoye Selo breed. Also, to confirm the fundamental role of the identified genes in formation of body size characteristics, studies on other chicken breeds are needed.