Genome-wide association studies of growth characteristics in chickens resource population

Genetic factors determine the growth potential of poultry in interaction with other environmental factors, which affects the final indicators of organism development. Whole-genome association study allows to identify links between genetic variations and phenotypic traits. The aim of our study was to search for SNPs associated with the growth of linear dimensions of chickens in the chest area during ontogenesis, characterizing meat productivity and development potential of poultry. The studies were conducted on F2 hens of a model resource population obtained by interbreeding hens of two breeds - Russian White (slow growth) and Cornish (fast growth). Phenotypic data were collected by taking linear measurements (chest width, depth and girth) at 2, 4, 6 and 8 weeks of age. Genotyping of the chickens F2 model resource population was carried out by applying commercial DNA-chips Illumina Chicken iSelect BeadChip 60k. In the chickens resource population, high variability in the growth and development indicators of the thoracic region was observed relative to the values of these indicators established in their purebred peers. The difference in linear measurements between the minimum and maximum values in the second-generation crossbreeds reached 77%. The conducted GWAS analysis revealed significantly significant SNPs (p<0.00001) associated with the growth rates of the chest and chest muscles in the resource population chickens. At the same time, SNPs were identified that were significant for a group of traits, including 13 SNPs associated with 7 or more studied linear measurements of F2 chickens of the resource population. The identified SNPs were localized on chromosomes GGA1 (2 SNPs), GGA2 (6 SNPs), GGA4, GGA11, GGA17, GGA18 and GGA20. The results obtained are of great importance for understanding the genetic architecture of chicken growth and can be used to improve breeding programs in poultry farming.