The expression analysis of growth-related genes in growth-related tissues in differential growth groups at different developmental stages of Megalobrama amblycephala

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 (P0.05). 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 (P0.05). 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 (P0.05). 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 similar 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 (P0.01).