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

Abstract

Reproductive traits are economically important for beef cattle production; however, these traits are still a bottleneck in indicine cattle since these animals typically reach puberty at older ages when compared to taurine breeds. In addition, reproductive traits are complex phenotypes, i.e., they are controlled by both the environment and many small-effect genes involved in different pathways. In this study, we conducted genome-wide association study (GWAS) and functional analyses 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 GWAS 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.

Mating to Intact, but Not Vasectomized, Males Elicits Changes in the Endometrial Transcriptome: Insights From the Bovine Model

“…Moreover, expression of some genes (PLA2G10, CX3CL1, C4BPA, PRSS2, BLA-DQB, and CEBPD) found differentially expressed in RNA-sequencing analysis of endometrium samples was also interrogated. The selection of these genes as interesting targets was based on literature searching (Wedel and Lömsziegler-Heitbrock, 1995;Blom et al, 2004;Hannan et al, 2004;Tapia et al, 2008;Hayashi et al, 2017;Neupane et al, 2017;Pinto De Melo et al, 2017;Tríbulo et al, 2018) and GO term analysis.…”

Across‐breed validation study confirms and identifies new loci associated with sexual precocity in Brahman and Nellore cattle

“…Melo, Camargo, Albuquerque, and Carvalheiro () in a GWAS of number of calving at 53 months of age (NC53), using the same Nellore population, found MHC Class II as the most significant term enriched for this trait. However, the genomic region found here (for G1) was the BTA23 at 6.9–7.4 Mb, while in Melo et al () the MHC genes were detected in another region, on BTA23 at 25–26 Mb. NC53 is a trait that reflects the ability of female to stay in herd productively, while EP represents the female precocity.…”

Genome-wide association study using haplotype alleles for the evaluation of reproductive traits in Nelore cattle

“…LOC513210 belongs to the olfactory gene family that was associated with precocity in Nelore cattle in a previous study[ 49 ]. The physiological explanation is that these genes with olfactory function also act on germ cells [ 49 , 50 ]. The expression of the FAAH gene occurs in the uterine epithelial cells and in the myometrium during the estrous cycle in rats.…”