Characterization of MSTN/GDF11 gene from shrimp Macrobrachium nipponense and its expression profiles during molt cycle and after eyestalk ablation

Myostatin (MSTN), also known as the growth differentiation factor-8 (GDF-8), belongs to the transforming growth factor-beta superfamily. MSTN is a negative regulator of muscle development in vertebrates. However, the transcriptional regulation of MSTN in freshwater crustaceans is still unclear. In this study, a cDNA encoding for MSTN/GDF11 (Mn-MSTN/GDF11) was cloned from the oriental freshwater shrimp, Macrobrachium nipponense. The full-length cDNA sequence of Mn-MSTN/ GDF11 was composed of 1733 nucleotides, including a 5' UTR of 119 nucleotides, an open read frame of 1359 nucleotides, and a 3' UTR of 255 nucleotides. The predicted peptide of Mn-MSTN/GDF11 has 452 amino acids with the conserved RXXR cleavage site and nine cysteines. Tissuespecific expression pattern showed that Mn-MSTN/GDF11 is mainly expressed in abdominal muscle. During the course of embryonic development, expression level of Mn- MSTN/GDF11 could be detected after gastrul stage, and reached at the highest level at embryonized-zoea stage. During molt cycle, expression level of Mn-MSTN/GDF11 mRNA was up-regulated significantly at early postmoult stage, but down-regulated gradually in the following molt stages. In the period of 14 days after eyestalk ablation, Mn- MSTN/GDF11 transcripts were significantly decreased in abdominal muscle and heart, but increased in thoracic muscle. The results of this study indicated that Mn-MSTN/ GDF11 may play a role in molt cycle and be regulated by hormone secreted in eyestalk.