Identification And Analysis Of Functional Mutation In KIAA1462 Promoter And Its Correlation With Egg-laying Performance In Yangzhou Geese

Yangzhou goose,mainly raised in Jiangsu province,which possess rapid growth and disease resistance,have been increasingly popular among breeding industry.The fact that laying performance that is closely related to the enterprise's economic benefit is an important economical trait of goose production,identification of related genetic markers is valuable for improving laying performance which is of low heritability originally.The SNP Record-134172(rsl714766362),which resides in the second intron of goose KIAA1462 gene,was found to strongly associated with laying performance in our previous study.However,the mechanism of the SNP function remains unexploned.In this paper,the KIAA1462 gene of Yangzhou geese,full-length coding region is 4029 bp,was firstly obtained by Comparative Genomic Study,whose expression was detected by Quantitative Real-time PCR with 11 tissues of Yangzhou geese,especially in the liver and ovary.What's more,the KIAA1462 had the highest level in mature F1 follicles among the developing ovarian follicles(P<0.05).Compared with different genotypes of SNP Record-134172(n=256),we found that geese with AA genotype had higher laying capacity than TA and TT.In addition,the expression of KIAA1462 mRNA in A A genotype was significantly higher than that in TA genotype(P<0.05)(n=16).The fact that the expression of Caspase-3,an apoptotic marker gene,was significantly decreased in the granulosa cells of Yangzhou goose(P<0.05)with the overexpression of KIAA1462 gene,while it was significantly increased(P<0.05)after KIA1462 knockdown,which suggests that KIAA1462 gene plays an important role in the regulation of follicular granule cell proliferation and apoptosis.Since SNP Record-134172 locates in the intron area,we conjectured that there might be a linked functional mutation in the promoter region.Compared sequence of KIAA1462 promoter region of AA and TT individuals,we have identified a novel SNP c.-413 C>G(db SNP ss2137504176)that predicted to reside in a binding element for glucocorticoid receptor(GR)completely linked to SNP Record-134172.Using electrophoretic mobility shift assay(EMSA)and luciferase assay we proved that GR can bind to the sequence with C but not G allele.In summary,we identified a novel mutation in the promoter region of KIAA1462 gene that could shift GR binding affinity and affect laying performance of geese,which can be used as a molecular marker in the goose breeding industry.