Genome wide association study on early puberty in Bos indicus

Abstract

ABSTRACT. The aim of this study was to evaluate a genome wide association study (GWAS) approach to identify single nucleotide polymorphisms (SNPs) associated with fertility traits (early puberty) in Nellore cattle (Bos indicus). Fifty-five Nellore cows were selected from a herd monitored for early puberty onset (positive pregnancy at 18 months of age). Extremes of this phenotype were selected; 30 and 25 individuals were pregnant and non-pregnant, respectively, at that age. DNA samples were genotyped using a high-density SNP chip (>777.000 SNP). GWAS using a case-control strategy highlighted a number of significant markers based on their proximity with the Bonferroni correction line. Results indicated that chromosomes 5, 6, 9, 10, and 22 were associated with the traits of interest. The most significant SNPs on these chromosomes were rs133039577, rs110013280, rs134702839, rs109551605, and rs41639155. Candidate genes, as well as quantitative trait loci (QTL) previously reported in the Ensembl and Cattle QTLdb databases, were further investigated. Analysis of the regions close to the SNP on chromosomes 9 and 10 revealed that four QTL had been previously classified under the reproduction category. In conclusion, we have identified SNPs in close proximity to genes associated with reproductive traits. Moreover, U6 spliceosomal RNA was present on three different chromosomes, which is possibly associated with age at first calving, suggesting that it might be a strong candidate for future studies.

Association between single nucleotide polymorphisms and sexual precocity in Nellore heifers

“…Using part of the data from the study of Hawken et al (2012), Fortes et al (2012) identified SNPs and chromosome regions that are directly associated with age at puberty of females and scrotal circumference in bulls. There have been some studies related to reproductive traits in zebu cattle such as: genome-wide association studies using 777k SNP panels (Irano et al, 2016;Nascimento et al, 2015;Costa et al, 2015), candidate gene/SNP studies (Fortes et al, 2013a,b), and combinations of methodologies (SNP association and gene expression; Fortes et al, 2014). The use of these technologies is being developed especially in tropical regions due to the importance of female performance in beef production profitability.…”

RELT family members activate p38 and induce apoptosis by a mechanism distinct from TNFR1

“…RELL1 was found to exhibit a circadian expression pattern in hepatocytes in a manner that is controlled post-transcriptionally by a microRNA [14]. RELL1 was identified as a gene associated with a higher rate of stillborn fetuses in pigs [15], is also implicated in the age of fertility in cattle [16], collectively suggesting that RELL1 may influence reproductive traits in humans. Finally, RELL1 has been associated with a higher incidence of S. aureus nasal carriage in a community-based sample of Mexican-Americans in a Texas community [17].…”

Dynamics of Selected Trace Minerals during Estrus Induction in Anestrus Sahiwal Cattle

“…Reproductive rates in Bos indicus are generally lower than Bos taurus mainly due to delayed puberty and prolonged postpartum anestrus (Nascimento et al, 2016). Incidence of true postpartum anestrus varying from 11% to 38%in exotic (Peter et al, 2009) to as high as 53.15% in Indian cattle breeds (Kumar et al, 2014) was recorded.…”