Expression profile and the G63A mutation of IGF2 gene associated with growth traits in Zhedong-White goose

Insulin-like growth factors 2 (IGF2) is an insulin-like growth factor that plays a major role in animal growth, cell proliferation and differentiation, as well as reproduction. IGF2 is well-known to be a candidate gene of growth and reproductive traits in many agricultural animals. Our previous study revealed that the G63A (Chr2: G26541617A) mutation within IGF2 exon 1 showed a significant association with egg numbers (E180d) of Sanhua goose population (p < 0.05). However, little work focus on the correlation between the IGF2 mutations and goose growth traits. In this study, qPCR indicated that the IGF2 mRNA highly expressed in leg muscle, liver, ovary and pituitary gland. Meanwhile, association analysis showed that the G63A mutation was significantly associated with the body weight of first-hatched Zhedong-White geese (BW0, p < 0.05), and strongly significantly associated with the BW2, BW4, BW6, BW8 and BW10 (p < 0.01). The GG homozygous had the lowest BW (from 4 weeks to 10 weeks) than those of AA and AG genotypes (p < 0.01), and the allele A was also positively correlated with the BW of the Zhedong-White goose population. Therefore, the G63A mutation in IGF2 may be an important genetic marker for goose breeding.