Identification of nucleotide polymorphisms in the key promoter region of chicken annexins A2 gene associatied with egg laying traits.

Annexin A2 () is a member of the A subfamily of a multifunctional calcium dependent membrane phospholipid binding protein family. The mRNA expression of is consistent with ovary function and egg laying in chickens. In this study, six nucleotide polymorphisms in the key promoter region of chicken gene (-2861bp to -1394bp), i.e.,: g.-2337 indel (GT), g.-2255 C>T, g. -2248A>G, g.-2188 A>G, g.-2169 G>A, g.-2160 A>C, were identified. Their distributions in populations of Xinyang Brown, Recessive White Rock, Wenchang and Wenshang Barred chickens were analyzed. In the Recessive White Rock chicken population, , and were three major haplotypes. Association analysis indicated that the individuals with diplotype / laid more eggs at 32weeks, and the individual with diplotype / laid at the earlier age. Luciferase activity assay showed that mutation from to at -2255 increased trascriptional activity of chicken , which is consistent with its effect on egg laying traits.