A polymorphism in the 3'-flanking region of insulin-like growth factor binding protein 2 gene associated with abdominal fat in chickens.

Insulin-like growth factor binding protein 2 (IGFBP2) is the predominant insulin-like growth factor binding protein in serum of different species. It binds insulin-like growth factors and plays an important role in growth and fat metabolism. The current study was designed to investigate the associations of IGFBP2 gene 3'-flanking region polymorphisms with chicken fatness traits. The random populations (5 distinct populations: Arbor Acres broiler, Hyline Brown layer, Shiqiza, BeijingYou, and Baier), the Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF), and the the Northeast Agricultural University F(2) (NEAU F(2)) resource population were used in the current study. Body weight and body composition traits were measured in NEAUHLF and NEAU F(2) populations. A SNP of 1196C > A in the 3'-flanking region of the IGFBP2 gene was detected, and the PCR-single strand conformation polymorphism method was then used to genotype all of the individuals derived from the above populations. There was a highly significant difference (P < 0.01) in the allele frequency among the 5 distinct populations. The IG-FBP2 polymorphism was significantly associated with abdominal fat weight and percentage of abdominal fat (P < 0.05) in NEAUHLF and NEAU F(2) populations. The research suggests that the IGFBP2 gene could be a candidate locus or linked to a major gene that affects fatness traits in chickens.