Molecular characterization of myostatin-like genes expressed highly in the muscle tissue from Morotoge shrimp, Pandalopsis japonica

Abstract

Myostatin is one of the transforming growth factor (TGF)‐β family members and plays inhibitory roles in the development and growth of muscle in mammals. Mammalian myostatins have been studied intensively, considering its medical and industrial potential use. Still, limited information is available about myostatin homologues in crustaceans. In the present study, we isolated for the first time cDNA that encodes for myostatin‐like protein (Pj‐MSTN) from Morotoge shrimp, Pandalopsis japonica. The putative mature peptide of Pj‐MSTN was composed of 109 amino acids, which contains an additional amino acid residue compared with mammalian myostatins. Pj‐MSTN exhibited 32% amino acid sequence identity and 52% similarity to human myostatin. Multiple sequence alignment analysis indicated that Pj‐MSTN shared the conserved proteolytic cleavage site (RXXR) for its maturation and nine cysteine residues for disulphide bridges. These results suggest that Pj‐MSTN has conserved the three‐dimensional structure of TGF‐β family members in vertebrates. Phylogenetic analysis suggests that Pj‐MSTN is a primitive form of vertebrate myostatin and GDF11. The expression of Pj‐MSTN was not just identified in muscular tissues, suggesting that Pj‐MSTN functions differently from mammalian myostatin. Ablation of the X‐organ/sinus gland complex significantly reduced the expression of Pj‐MSTN in most tissues, suggesting its potential association with moulting.

Growing backwards: an inverted role for the shrimp ortholog of vertebrate myostatin and GDF11

“…It stands to reason that a combined functional role of the iMstn/Gdf11 gene may be reflected in a broader tissue gene expression profile, one that is less specialized than that of the vertebrate Mstn or Gdf11 paralogs. Indeed, transcripts of the pmMstn/Gdf11 gene were expressed in a wider variety of shrimp tissues, including muscle, gills, heart, eyestalk and hepatopancreas, similar to the expression observed in other crustaceans such as P. japonica, G. lateralis and H. americanus (Covi et al, 2008;Kim et al, 2010;MacLea et al, 2010).…”

“…Loss-offunction mutations of the MSTN gene in vertebrates result in heavily muscled phenotypes (McPherron and , whereas increasing circulating levels of MSTN induces muscle atrophy (Ma et al, 2003;Shao et al, 2007;Wehling et al, 2000). Recently, invertebrate orthologs of genes similar to Mstn have been reported in a number of species, including decapod crustaceans (Covi et al, 2008;Covi et al, 2010;Kim et al, 2010;MacLea et al, 2010); however, the function of these gene orthologs has not been specifically investigated.…”

“…Despite being reported under a diverse range of names -such as myoglanin in Drosophila melanogaster; Mstn-like gene in Argopecten irradians, Homarus americanus, Pandalopsis japonica and Gecarcinus lateralis; Mstn/Gdf11 in Nematostella vectensis; and Gdf8/11 in Branchiostoma belcheri -invertebrates have only had one ortholog of vertebrate Mstn and Gdf11 isolated to date (Covi et al, 2008;Kim et al, 2004;Kim et al, 2010;Lo and Frasch, 1999;MacLea et al, 2010;Saina and Technau, 2009;Xing et al, 2007). For clarity, we refer to the abovementioned proteins as the invertebrate MSTN/GDF11 (iMSTN/GDF11).…”

Enhanced muscle regeneration in freshwater prawn Macrobrachium rosenbergii achieved through in vivo silencing of the myostatin gene

“…This led to a study on the characterization of the role of MSTN specifically in the aquaculture sector as muscle regeneration in crustaceans is believed to be closely associated with the molting process (Saravanan, Kamalam, & Kumar, ). In crustaceans, MSTN is reported to regulate the molting process as the ablation of the X‐organ/sinus gland complex downregulates the expression of MSTN in most tissues in Pandalopsis japonica (Kim et al, ), and high MSTN expression is observed in skeletal muscle during the intermolt stage in Gecarcinus lateralis (Covi, Kim, & Mykles, ). Most studies have demonstrated the functional role of MSTN in crustaceans on the basis of changes in MSTN gene regulation, but further studies are required to distinguish its role in the regeneration process as established in vertebrates.…”

Rheb, an activator of target of rapamycin, in the blackback land crab,Gecarcinus lateralis: cloning and effects of molting and unweighting on expression in skeletal muscle

“…Mstn may also regulate muscle growth in invertebrates. cDNAs encoding Mstnlike proteins have been characterized in mollusks and arthropods (Covi et al, 2008;De Santis et al, 2011;Hu et al, 2010;Kim et al, 2004;Kim et al, 2009;Kim et al, 2010;Lo and Frasch, 1999;MacLea et al, 2010). In blackback land crabs (Gecarcinus lateralis), molt-induced atrophy and unweighting atrophy have opposite effects on Gl-Mstn expression in claw closer and thoracic muscles, respectively.…”