Genome-wide association study of molecular markers related to keel length in a specialized strain of yellow feathered broilers

Keel length is a key body size indicator, which has an important impact on the overall growth performance, bone health, and production performance of poultry. In the process of selecting crossed strains for yellow feathered broiler chickens, it is generally necessary to select keel length, but there is little research on keel length development. Therefore, resequencing and GWAS was employed to obtain SNP molecular markers associated with keel length in a specialized Yellow-feathered broiler line. We identified 10 SNPs that were potentially significantly correlated with keel length for the first time located at 9 genes, including ATP7B, CST3, OTOP1, CRMP1, SLC12A1, COPS2, FAM227B, IFT140, APLP2. SNP2 and SNP3 loci were in a strongly linked state (D ' value=1), the other 8 SNP loci were not in a strongly linked state (D 'value<1). The association analysis between single SNP marker and keel length traits showed that TT and CT at SNP1 (rs315701680), GG at SNP2 (rs738740137), AA at SNP3 (rs317223723), AA at SNP4 (rs732443622), GG at SNP5(rs315667756), CC at SNP6 (rs314381113), GG at SNP7 (rs732811384), TT at SNP8 (rs314197610), CC and TC at SNP9 (rs13782000), TT and GT at SNP10 (rs737401141) genotypes were all the dominant genotypes for keel length. The strong linkage between SNP2 and SNP3 resulted in two haplotypes H1 (AG) and H2 (GA), respectively. The H1H1 haplotype (GGAA) produced by SNP2 and SNP3 linkage was the dominant genotype for keel length. The SNP molecular markers and dominant genotypes at SNP1-SNP10 loci identified in this study may be used to improve the accuracy and genetic progress of keel length selection. Meanwhile, candidate genes potentially significantly related to keel length will lay the foundation for genetic selection of keel length and cultivation of high-quality yellow feathered broilers in the future.