Olfactory Receptor Genes Associated to Precocious Puberty in Nellore Heifers

Fertility are a complex trait which are influenced by many genes. Some of these genes have directly effect on traits but many ones have indirectly effect. Recent advances in genomics have greatly expanded our ability to study how these genes affect certain features, as reproductive. Thus, this study aimed a better understanding how signatures of selection are associated to reproductive features. To determine recent signatures of selection in quantitative trait locus (QTL) previously mapped for reproductive cow features linked to precocious puberty, 2,035 Nellore females were genotyped with the Illumina BovineSNP50 chip (>777 000 SNPs). After, connection phase of SNPs was inferred for haplotype reconstruction. Signatures of selection were detected by Relative Extended Haplotype Homozygosity method. Genes supposedly important in these regions were recognized by a Map Viewer from the National Center for Biotechnology Information (NCBI), and a loaded GBrowse with bovine genome UMD, version 3.1. Signatures of selection on BTA29 evinced presence of multiple genes under selection, whose belonged to family of olfactory receptor (ORs) genes. These genes have been reported to influence the behavioral characteristics of mammals, since these receptors allow mammals ability to capture odorous molecules in the air and translate them into information, resulting favorable responses to survival, feeding and reproduction. Thus, ORS influence feed intake and consequently whole metabolism, toward greater weight gain and body condition for cycling of females. Moreover, ORs play important role on germinatives cells can affecting production of gamete and, consequently, precocious puberty. So despite the ORs often are not directly related to reproductive metabolism, these genes may be indirectly related to these feature.