南阳牛肌肉发育过程中IGF基因家族的表达变化研究

 IGF基因家族对肌肉发育起重要的调控作用，而目前对牛肌肉发育过程中IGF基因家族的表达变化研究还不充分。本研究利用荧光实时定量PCR技术分析了南阳牛3月龄到24月龄期间背最长肌组织中IGF，IGF受体和IGF结合蛋白基因的表达变化规律，发现IGF1，IGF2，IGF1R，IGF2R，IGFBP1和IGFBP3的表达量均呈现出明显的下降趋势，其中18月龄和24月龄时的表达量与3月龄时相比显著低（P<0.05）；IGFALS也呈现出下降的趋势，但表达量在各个时期没有显著的差异（P>005）；IGFBP2，IGFBP4和IGFBP6在6月龄时表达量上升，在12月龄和18月龄时表达量降低，在24月龄时表达量再次上升，但各个时期表达量均无显著差异（P>005）；IGFBP5表现出先升高而后降低的趋势，6月龄比24月龄时表达量显著高（P<005），其他各月龄之间差异不显著。本研究对IGF基因家族在南阳牛肌肉发育过程中的表达变化进行了系统的研究，为进一步深入分析IGF系统在牛肌肉发育过程中的作用提供了有力的理论基础。

The Time Serial Expression Pattern of IGF Superfamily in Longissimus dorsi Muscle of Nanyang Cattle

The IGF superfamily members play important roles in the controlling of muscle development, while these genes had not been deeply studied in cattle. The time serial expression pattern of IGF, IGFR and IGFBPs were analyzed by real time quantity PCR in Longissimus dorsi muscle from 3 month old to 24 month old. The results showed that the expression of IGF1, IGF2, IGF1R, IGF2R, IGFBP1 and IGFBP3 showed descending patterns. The expression levels at 18 month old and 24 month old were significant lower than that at 3 month old (P<005). The expression of IGFALS also showed descending patterns but had no significant different between stages (P>0.05). The expression levels of IGFBP2, IGFBP4 and IGFBP6 raised at 6 month old, then decreased at 12 month and 18 month old and raised at 24 month old again, but had no significant changes during the experiment (P>005). The expression of IGFBP5 raised at 6 month and 12 month old, while decreased at 18 month and 24 month old, and showed significant difference between 6 month and 24 month old (P<0.05). This paper performed overall studies on the expression of IGF superfamily members and provided strong supports for the function analysis of IGF superfamily members on the control of skeletal muscle development.