Association analysis of IGF2 gene polymorphisms with growth traits of Dezhou donkey.

IGF2 is an insulin-like growth factor that plays an important role in the development of animal embryos. In order to determine whether IGF2 gene is associated with important economic characteristics of donkeys, we investigated the association between single nucleotide polymorphisms (SNPs) of IGF2 gene and body size traits of Chinese Dezhou donkeys and analyzed the expression level of IGF2 gene in different tissues of juvenile and adult Dezhou donkeys. In this study, two SNPs (g.281766 G > A and g.291322 C > T) were detected in IGF2 gene, both of which were in Hardy-Weinberg equilibrium (P > 0.05) and were moderately polymorphic (0.25 < PIC < 0.50). Association analysis showed that the two SNP loci were significantly correlated with body length and rump height (p < 0.05) of female Dezhou donkeys. Quantitative results showed that the expression of IGF2 gene was higher in heart, liver, spleen, lung, kidney, stomach and muscle tissues of juvenile donkeys than that of adult donkeys. Together, IGF2 can be considered as a candidate gene for growth and development of female Dezhou donkey, and its polymorphism can be used as a molecular marker for the Dezhou donkey breeding.