A Functional Mutation in KIAA1462 Promoter Decreases Glucocorticoid Receptor Affinity and Affects Egg-Laying Performance in Yangzhou Geese

The identification of genetic markers is valuable for improving the egg-laying performance in goose production. The single-nucleotide polymorphism (SNP) rs1714766362 in an intron of the goose KIAA1462 gene was found to be relevant to laying performance in our previous study. However, its function remains unclear. In this study, the full-length coding sequence of KIAA1462 gene was firstly characterized in Yangzhou geese. Q-PCR (Quantitative Real Time Polymerase Chain Reaction) results showed that KIAA1462 was highly expressed in the liver, ovary, and mature F1 follicles. For SNP rs1714766362, geese with the AA genotype showed better laying performance than the TT ones and exhibited a higher KIAA1462 expression level in the ovary. Gain- and loss-of function experiments in granulosa cells revealed that KIAA1462 affected the expression of the apoptosis marker gene caspase-3. Considering that rs1714766362 locates in an intron area, we compared the KIAA1462 promoter regions of AA and TT individuals and identified the SNP c.-413C>G (Genbank ss2137504176), which was completely linked to SNP rs1714766362. According to the transcription factor prediction results, the glucocorticoid receptor (GR) would bind to the SNP site containing the C but not the G allele. In this study, we proved this hypothesis by an electrophoretic mobility shift assay (EMSA). In summary, we identified a novel mutation in the promoter of KIAA1462 gene which can modulate GR binding affinity and affect the laying performance of geese.