Runs of homozygosity (ROHom), continuous stretches of homozygous loci, and runs of heterozygosity (ROHet), continuous stretches of heterozygous loci, may be due to directional (ROHom) or balancing selection (ROHet) and are interesting to analyze those shared among animals within a population and the genes they harbor. The detection of both types of genomic regions is influenced by genotyping density and involved parameters. Thus, this work aimed to study the impact of the BeadChip density on the ROHom and ROHet detection in the Italian Simmental cattle breed. Results showed that the ROHom detection is more reliable as the density increases, whereas a more cryptic pattern was observed for ROHet. Interestingly, the hypothesis on how these two types of runs arise was supplied by the results of this study. The genes mapped on the highlighted ROHet were mainly associated with fitness traits, health, and reproduction, whereas those found in the ROHom were associated with production traits.

Read the full article in the Journal of Animal Science.