Genome-wide association study provides strong evidence of genes affecting the reproductive performance of Nellore beef cows

• Grant number: 17/10845-9
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: July 01, 2017
• End date: December 31, 2017
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Genetics and Improvement of Domestic Animals
• Principal Investigator: Roberto Carvalheiro
• Grantee: Roberto Carvalheiro
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

Genome-wide association (GWA) and functional analyses were conducted aiming to identify important genes and pathways associated with heifer rebreeding (HR) and with the number of calvings at 53 months of age (NC53) in Nellore cows. A total of 142,878 and 244,311 phenotypes for HR and NC53, respectively, and 2,925 animals genotyped with the Illumina Bovine HD panel (Illumina®, San Diego, CA, USA) were used in GWA applying the weighted single-step GBLUP (WssGBLUP) method. Several genes associated with reproductive events were detected in the 20 most important 1Mb windows for both traits. Significant pathways for HR and NC53 were associated with lipid metabolism and immune processes, respectively. MHC class II genes, detected on chromosome 23 (window 25-26Mb) for NC53, were significantly associated with pregnancy success of Nellore cows. These genes have been proved previously to be associated with reproductive traits such as mate choice in other breeds and species. Our results suggest that genes associated with the reproductive traits HR and NC53 may be involved in embryo development in mammalian species. Furthermore, some genes associated with mate choice may affect pregnancy success in Nellore cattle. (AU)