New Genomic Insights into the Conformation of Lipizzan Horses

Abstract

Abstract Conformation traits are important selection criteria in equine breeding, as they describe the exterior aspects of the horse (height, joint angles, shape). However, the genetic architecture of conformation is not well understood, as data of these traits mainly consist of subjective evaluation scores. Here, we performed genome-wide association studies (GWAS) on two-dimensional (2D) shape data of Lipizzan horses. Based on this data, we identified two significant quantitative trait loci (QTL) related to a heavy or light type of horse on equine chromosome (ECA) 16 within the MAGI1 gene and on ECA5 within the POU2F1 gene. Both genes were previously described to affect growth and muscling in sheep, cattle and pigs. Furthermore, we pin-pointed another suggestive QTL on ECA 21, near the PTGER4 gene, associated with human ankylosing spondylitis, for shape differences in the back and pelvis (roach back vs sway back). Further differences in the shape of the back and abdomen were suggestively associated with the RYR1 gene, involved in core muscle weakness in humans. Therefore, we demonstrated, that horse shape space data enhance the genomic investigations of horse conformation.