The HaeIII and XspI PCR-RFLPs detecting polymorphisms at the goat IGFBP-3 locus

Insulin-like growth factor binding protein-3 (IGFBP-3) gene is a structural gene responsible for the multiple influences of insulin-like growth factors (IGFs) system, an evolutionarily conserved signaling pathway. In this study, we detected for the first time the polymorphisms of goat IGFBP-3 gene by PCR-SSCP and DNA sequencing methods in 767 samples. The four mutations (namely, EX2_58C>T resulting in P155S change, EX2_67C>G producing R158G change, IVS2+78A>G and IVS2+217G>A) were firstly described at the goat IGFBP-3 locus. Hence, we described the HaeIII and XspI PCR-RFLPs methods for detecting EX2_67C>G and IVS2+217G>A mutations, respectively. In the PCR-RFLP analysis with HaeIII, the frequencies of goat IGFBP-3-H2 allele varied from 0.000 to 0.181 in seven Chinese native breeds. In the PCR-RFLP analysis with XspI, the frequencies of goat IGFBP-3-X1 allele were 0.507, 0.700, 0.831, 0.283, 0.242, 0.147 and 0.162 for Xinong Sannen, Laoshan, Guanzhong, Inner Mongolia White Cashmere, Guizhou White, Leizhou and Shaannan White populations. The associations of the HaeIII and XspI PCR-RFLPs of goat IGFBP-3 locus with milk traits were analyzed in dairy goat, but the significant statistical results were not found between them (P > 0.05).