cDNA cloning and expression analysis of myostatin/GDF11 in shrimp, Litopenaeus vannamei

Myostatin (MSTN) and growth differentiation factor-11 (GDF11) are closely related proteins belonging to the transforming growth factor-β (TGF-β) superfamily. In vertebrates, MSTN is known to negatively regulate skeletal muscle growth, and GDF11 is found to inhibit neurogenesis. In invertebrates, only one ortholog of vertebrate MSTN and GDF11 (MSTN/GDF11) existed. Little attention has been paid on its role to date. In this study, the cDNA that encodes a 422-amino-acid MSTN/GDF11 protein (LvMSTN/GDF11) was characterized from a crustacean species, the Pacific white shrimp (Litopenaeus vannamei). Sequence analysis revealed that the overall protein sequence and specific functional sites of LvMSTN/GDF11 were highly conserved with those in other crustacean species. Expression analysis by quantitative real-time reverse transcription polymerase chain reaction technique demonstrated its tissue-specific, larval developmental stage-specific, and molt stage-specific expression pattern, respectively. After in vivo injections of 20 hydroxyecdysone (20E), LvMSTN/GDF11 transcripts were declined in the abdominal (A) and pleopod (P1) muscles, increased in the pereiopod (P2) muscle, and not affected in the thoracic (T) muscle. The observed expression profiles suggest multiple functions of LvMSTN/GDF11 in L. vannamei and its role differs during the larval development and natural molt cycle. The different responses of LvMSTN/GDF11 to acute increases of 20E in the A, P1, P2 and T muscles may indicate that LvMSTN/GDF11 is transcriptionally regulated via ecdysteroids to coincide with its specific roles in the former three muscles, while its role may be independent of 20E regulation in the T muscle.