Early Development and Developmental Expression of Insulin-like Growth Factor 1 Receptor(IGF-IR) mRNA in Gaoyou Duck and Jinding Duck(Anas platyrhynchos domestica) Skeletal Muscle
Abstract：Insulin-like growth factors play an important role in animal growth and nutrition metabolism. In order to research the effects of IGF-1 receptor(IGF-IR) gene on the skeletal muscle in early development stage of duck, the IGF-IR mRNA expressions on the skeletal muscle during Gaoyou duck and Jinding duck (Anas platyrhynchos domestica) embryonic stage on day 13, 17, 21, 25, 27 and 1 week after patch were detected using quantitative RT-PCR method in this experiment. The result indicated that the profiles of IGF-IR mRNA in muscle in two duck breeds were relatively consistent during early development which showed "wave" trend in pectorales and "L" trend in legs. Expression levels of IGF-IR gene on pectorals at 13 and 21 embryo age were higher, and the subsequent expression levels were somewhat lower at 25 and 27 embryo age and its expression levels in the newborn period(7 days) were slowly upward; the expression of duck IGF-IR gene on legs showed that the highest level appeared at 13 embryo age, and subsequently expression levels decreased to maintain a relatively low expression levels. Within the same breed, the expression levels of IGF-IR mRNA in pectorals were significantly higher than that in legs except for 13 embryo age(P<0.01). The result of bivariate correlate analysis showed that the expression of IGF-IR gene and weight development in pectorales and legs were negatively correlated and the correlate coefficient in legs was stronger. These results indicated that IGF-IR gene involved in the skeletal development, and different expression patterns in the pectorals and legs suggested IGF-IR gene may be related to the chest and leg muscle development and differentiation, and the expression of IGF-IR gene in muscle was important in the early growth and development in ducks. The analysis of IGF-IR gene in early development of skeletal muscle in Gaoyou duck and Jinding duck will provide theoretical basis for studing hormone regulation mechanism in duck.
