Analysis of genome-wide associations with tarsus length in Tsarskoye selo, Uzbek Game and Cornish breeds

Morphological characteristics of the skeleton have a special influence on economically useful traits. Phenotypic data indirectly reflect an individual's genetic potential. Tarsus length is one of the main indicators of bone development, which is due to the correlation of this parameter with live weight. The aim of the present study was to identify candidate regions responsible for the tarsus length. Studies were conducted on Tsarskoye Selo, Uzbek Game and Cornish breeds. One candidate region on chromosome 9 associated with metatarsal length was identified based on whole-genome genotyping data and GWAS-analysis results. The identified region contained 50 SNPs localized in EIF4A2, RFC4, MCF2L2, LAMP3, MCCC1, and DCUN1D1 genes that maximally distinguished the breeds from each other. Some genes are involved in the processes of skeletal muscle formation and homeostasis, others in the processes of bone homeostasis and autophagy, as well as in the development and course of osteosarcoma. The greatest differences in allele frequencies between Cornish and Uzbek Game breeds are observed in SNPs of MCCC1, LAMP3, and MCF2L2 genes. Interestingly, for SNPs of the same genes, the maximum similarities of allele frequencies were observed in Tsarskoye Selo and Uzbek Game breeds. The present study expands the existing knowledge on the mechanisms controlling growth and development of chicken bone structures.