Prospecting polymorphisms in the PPP3CA and FABP4 genes and their association with early pregnancy probability in Nellore heifers

Early pregnancy probability (P16) in heifers is a trait of high economic value for beef cattle production. Early pregnancy is defined based on the conception and calving of a heifer given that the animal had entered the breeding season at about 16 months of age and is considered a strong predictor of puberty in Nellore cattle. The aim of this study was to identify polymorphisms in the protein phosphatase 3 - catalytic subunit, alpha isozyme (PPP3CA) and fatty acid-binding proteins 4 (FABP4) genes, which have been associated with P16. The exon regions of the candidate genes were sequenced in 380 heifers. Two polymorphisms were detected in PPP3CA and 13 in FABP4. A deletion (rs134413439) was identified in the FABP4 gene in all samples, which could be a variation that occurs across breeds since the reference genome is from a Hereford cow. Two SNPs in the FABP4 gene were associated with P16 after Bonferroni correction. However, none of the haplotypes exerted a significant effect (P > 0.05). This study showed that the PPP3CA and FABP4 genes are polymorphic in Nellore cattle. Furthermore, the FABP4 gene was found to be associated with early pregnancy in heifers, reinforcing the contribution of lipid metabolism to reproduction.