[Developmental expression changes of IGF2 and IGFBP3 genes in adipose tissue of two pig breeds]

To investigate the developmental expression patterns of Insulin-like Growth Factor 2 (IGF2) and Insulin-like Growth Factor Binding protein 3 (IGFBP3) genes at the age of 30, 60, 90, 120 and 150 days in back subcutaneous fat tissue of Landrace and Taihu pigs, real-time fluorescence quantitative PCR was applied. Results showed that the expression level of IGF2 mRNA in Landrace pigs was significantly higher at 30 days than other days (P<0.01), then gradually declined and lowest at 120 days, obviously increased at 150 days. In Taihu pigs, it was relatively higher at 30~60 days, lowest at 90 days, increased rapidly at 120 days, and then decreased. Developmental expression patterns of IGFBP3 mRNA in the two pig breeds were similar, which were highest at 30 days, declined significantly at 60 days (P<0.05) then maintained steady, but a little fluctuant between ages in each breed. In addition, the expression level of IGF2 mRNA in Taihu pigs was significantly higher than that of Landrace pigs at the age of 120 days (P<0.01), and the expression level of IGFBP3 mRNA in Taihu pigs was significantly lower than that of Landrace at the age of 150 days (P<0.01), with no significant difference between the two pig breeds at other ages (P>0.05). The results suggest that the expression of IGF2 and IGFBP3 mRNA in the adipose tissue of pigs exhibits specific developmental changes and different patterns between the two pig breeds. The expression decrease of IGF2 may be related to adipocyte hyperplasia.