Candidate genes for height measurements in Campolina horses

Context. Genomic tools allow for increased efficiency in animal production and, consequently, greater production gains. Morphometric measurements of height can be used for breed characterisation/registration, and sex distinction, in addition to being associated with balance, posture, and the range of motion of the limbs, influencing the dynamics and quality of the gait. Aims. This study was conducted to examine candidate genes related to the morphometric measurement of heights in Campolina horses. Methods. The study involved information from 18 876 horses of this breed, containing phenotypic data of the measurements of withers, croup, back, and barrel heights, provided by the Brazilian Association of Campolina Horse Breeders (ABCCCampolina). Of these, 48 horses of the Brazilian Campolina breed were genotyped with the Equine 65 K lllumina (R) chip. The effects of the single-nucleotide polymorphisms were estimated by the weighted single-step method, using BLUPF90 family programs. Genes in the main chromosomal regions were identified by consultation with the NCBI. Key results. A genomic-wide association study for withers height showed that 46% of the variation in this measurement was explained by 20 genomic windows. For croup height, 19 genomic windows were responsible for explaining 44% of the variation. Sixteen genomic windows were responsible for explaining 37.8% of the variation in back height and 18 genomic regions explained 39.7% of the variation in barrel height. Conclusion. The ADAM17, SOX11, and KLF11 genes are located in the genomic windows that most explain the variations in the traits under study and have a biological action on the locomotor system. Implications. The ADAM17, SOX11, and KLF11 genes are candidates for fine mapping and construction of molecular markers.