A novel p.K116Q SNP in the OLR1 gene and its relation to fecundity in Awassi ewes

Abstract

Sheep's fecundity is determined by both twinning rate and litter size, both influenced by several genes, one of which is the OLR1 (oxidized low-density lipoprotein receptor) gene. This study aimed to determine the genetic variation of the OLR1 gene affecting the fecundity traits of Awassi ewes. The genomic DNA from 114 ewes with a single progeny and 86 ewes with twins was extracted. Polymerase chain reaction (PCR) was used to amplify three fragments (334 bp, 291 bp, and 274 bp) (exon 3, exon 4, and exon 6) of the OLR1 gene. Two genotypes of 334-bp amplicons – CC and CA – were detected. In a sequence reaction, the novel mutation p.K116Q was discovered in CA genotypes. There was a highly significant (P ≤ 0.01) association between the single nucleotide polymorphism (SNP) and reproductive traits, in that ewes with the p.K116Q SNP had lower litter size, twinning rate, fecundity, and lambing percentages than ewes with the CC genotype. These observations imply that the missense p.K116Q variant has an adverse effect on the traits under study and show that p.K116Q SNP has a negative influence on fecundity traits in Awassi sheep. Based on the findings of this study, it is clear that ewes with the p.K116Q SNP are associated with reduced litter size and reduced fecundity traits for this population.