Full Length Research Paper

Polymorphism in NPY and IGF-I genes associate with reproductive traits in Wenchang chicken

H. F. Li¹*, W. Q. Zhu¹, K. W. Chen¹, X. Wu², Q. P. Tang¹, Y. S. Gao¹, W. T. Song¹, W. J. and Xu, H. L.^1,2

¹Institute of Poultry Science, Chinese Academy of Agriculture Science, Yangzhou, 225003, China.

²Fujian Agriculture and Forestry Yniversity, College of Animal Science, Fuzhou, 350002, China.

*Corresponding author. E-mail: lhfxf_002@yahoo.com.cn. Tel.: +86-514-87207327. Fax: +86-514-87207327.

Accepted 10 August, 2009

   Abstract

Alleles of physiological candidate genes for reproductive traits, insulin-like growth factor-I (IGF-I) and neuropeptide Y (NPY) were assessed to determine the association with total egg production (NE), average days of continual egg-laying (ADCE) and number of double-yolked eggs (DYE) in Wenchang chicken (Chinese indigenous breed). PCR-RFLP method was used for genotypes identification. The frequency of restriction enzyme A/a alleles in the population was 0.46 (A) and 0.54 (a) for NPY. The frequency of restriction enzyme B/b alleles in the population was 0.53 (B) and 0.47 (b) for IGF-I, respectively. Four significant associations were found (P < 0.05): between NPY and NE (300 d) and between IGF-I polymorphism and NE (300 d), NE (400 d) and ADCE. Two significant effects were observed: for NPY and NE (300 d) and for IGF-I and NE (300 d). The current research supports the effects of NPY and IGF-I genes on reproductive traits of chickens.

Key words: Chicken, NPY, IGF-I, reproduction, SNP.