Meta-Analysis of Heifer Traits Identified Reproductive Pathways in Bos indicus Cattle

Fertility traits measured early in life define the reproductive potential of heifers. Knowledge genetics and biology can help devise genomic selection methods to improve heifer fertility. In this study, we used ~2400 Brahman cattle perform GWAS multi-trait meta-analysis determine regions associated with Heifer were pregnancy at first mating opportunity (PREG1, a binary trait), conception score (FCS, 1 3) rebreeding (REB, 3.5). The heritability estimates 0.17 (0.03) for PREG1, 0.11 (0.05) FCS 0.28 REB. three highly genetically correlated (0.75–0.83) as expected. Meta-analysis was performed using SNP effects estimated each traits, adjusted standard error. We identified 1359 significant SNPs (p-value < 9.9 × 10−6 FDR 0.0001) meta-analysis. Genomic 0.5 Mb around from annotated create list 2560 positional candidate genes. most vicinity region on chromosome 8, encompassing genes SLC44A1, FSD1L, FKTN, TAL2 TMEM38B. humans that contains homologs these is age puberty girls. Top pointed additional fertility-related genes, again within region, including ESR2, ITPR1, GNG2, RGS9BP, ANKRD27, TDRD12, GRM1, MTHFD1, PTGDR NTNG1. Functional pathway enrichment analysis resulted many relating known fertility pathways, GnRH signaling, estrogen progesterone mediated oocyte maturation, cAMP calcium glutamatergic focal adhesion, PI3K-AKT signaling ovarian steroidogenesis pathway. comparison results study previous transcriptomics proteomics studies same breed (Brahman) but different population 392 common which some genes—BRAF, GABRA2, GABR1B, GAD1, FSHR, CNGA3, PDE10A, SNAP25, GRIA2, ORAI1, EGFR, CHRNA5, VDAC2, ACVR2B, ORAI3, CYP11A1, GRIN2A, ATP2B3, CAMK2A, PLA2G, CAMK2D MAPK3—are also part above-mentioned pathways. biological functions their annotation pathways allowed integrating into bigger picture molecular mechanisms related hypothalamus–pituitary–ovarian axis. A reasonable number between corroborates proposed mechanisms. This polymorphism provided visualization mechanisms, coordinating hypothalamic, pituitary, performance cattle.