Identification of a Single Nucleotide Polymorphism of the Insulin-like Growth Factor Binding Protein 2 Gene and Its Association with Growth and Body Composition Traits in the Chicken

Insulin-like growth factor binding protein 2 regulates a broad spectrum of biological activities involved in growth, development, and differentiation. The current study was designed to investigate the associations of IGFBP2 gene polymorphisms with chicken growth and body composition traits. The Northeast Agricultural University Resource Population (NEAURP) was established by crossing broiler sires, derived from lines at Northeast Agricultural University, that were divergently selected for abdominal fat, with Baier layer dams, a Chinese local breed. The F1 birds were inter-crossed to produce an F2 population. Body weight and body composition traits were measured in the NEAURP. The PCR primers for the intron 2 region of IGFBP2 were designed based on chicken genomic sequence. Nucleotide polymorphisms between parental lines were detected by DNA sequencing. A C/T SNP in intron 2 was detected, and PCR-RFLP methods were then developed to genotype the F2 individuals. The results showed that the IGFBP2 SNP was associated with multiple traits, including BW, metatarsus length, shank length, femur length, shank weight, femur weight, metatarsus claw weight, and abdominal fat weight in the 1,028 NEAURP F2 individuals. This research suggests that IGFBP2 or a tightly linked gene has broad effects on growth and development in the chicken.