团头鲂生长相关基因在不同发育时期生长轴组织的表达分析

摘要

为了探讨生长相关基因对团头鲂生长发育的调控,研究采用Real-time PCR的方法定量分析了团头鲂6个生长相关基因在其不同生长发育阶段(3、6、12月龄)相关组织(脑、肝脏、肌肉)的表达情况,并比较了这些基因在生长快和慢两个群体的表达差异。结果显示： GHRs 基因在肝脏与肌肉中的表达量高于脑,在6月龄表达量高于3月龄与12月龄,生长快群体中的表达量高于生长慢群体(P<0.05)；IGFs基因在三个组织中均有表达,肝脏表达量最高,生长快群体中的表达量高于生长慢群体(P<0.05)。MSTN a与MSTN b基因在组织中表达模式存在差异, MSTN a在肌肉中高表达, MSTN b主要在脑与肝脏中表达。HCL聚类结果表明：除了MSTN a基因外,其他5个基因在生长差异的两个群体中表达量均分别聚为一支。不同时期组织表达聚类结果表明,除了3月龄肝脏与12月龄肌肉组织,6个生长相关基因在不同时期的同一组织中的表达模式存在相似性。Pearson相关分析显示：GHRs与IGFs呈正相关, MSTN a基因与GHR 2、IGFs基因呈负相关,相同基因在两个群体中呈极显著相关(P<0.01)。%In this study, we investigated the expression of growth-related genes in differential growth groups at different developmental stages of M. amblycephala. We employed real-time PCR to quantify the expression of six growth-related genes in the brain, the liver and muscles. The results revealed that GHRs genes were highly expressed in the liver and muscles, and their expression level in 6-month and 12-month-old fish was higher than that in 3-month-old fish, and the expression level in the fast-growing group was higher than that in the slow-growing group (P<0.05). IGFs genes were expressed in all three tissues, and the expression in the liver was the highest. The expression of IGFs decreased as the fish grew older (P<0.05). MSTN a was primarily expressed in the brain and the liver. Unlike MSTN a, MSTN b was highly expressed in the muscles. Moreover, the expression levels of MSTN genes were negatively correlated with the growth rates (P<0.05). The Cluster analysis showed that except for MSTN a, the expression levels of the other five genes in the differential growth groups could be clustered. The cluster results revealed that the expression patterns were simi-lar in different growth-related tissues at different stages, except in the liver at 3 month and the muscles at 12 month. A positive correlation between the expression levels of MSTN a and GHR 2 was observed in the present study with Pearson correlation analysis. The similar correlation was also observed between MSTN a and IGFs. Furthermore, there was a significant positive correlation between the two differential growth groups in terms of the expression of the growth-related genes (P<0.01).