Genomic structural diversity in Criollo Argentino horses: Analysis of copy number variations.

Copy number variation (CNV) has been proved to be widespread in human, animal and plant genomes. Together with single nucleotide polymorphisms (SNPs), CVNs play a key role in genetic diversity. In this study, genome-wide detection of CNVs was performed based on SNP data from 24 Criollo Argentino horses genotyped with the GGP Equine70k array. Overall, 165 CNVs meeting stringent quality control criteria were identified and then aggregated into 87 CNV regions (CNVRs), representing a horse genome coverage of 13.69 Mb. Functional analysis of CNVRs allowed the identification of 337 genes implicated in a wide range of biological functions such as signal transducer activity (olfactory receptors), receptor activities and binding. Furthermore, enrichment analysis showed that the most represented protein classes (over 25%) were immunoglobulin receptor subfamily, immunoglobulins and major histocompatibility complex antigen (beta-2-microglobulin). To the best of our knowledge, this is the first report of CNV in Criollo Argentino horses.