• Journal of Life Science
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• v.22 no.4
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• pp.486-491
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• 2012

Myostatin (MSTN), a member of the transforming growth factor (TGF)-beta family, is a potent negative regulator of skeletal muscle growth and maintenance. The MSTN prodomain inhibits MSTN biological activity. The rotifer Brachionus rotundiformis is an excellent primary live feed for fish larvae in aquaculture; however, it is not known whether the rotifer expresses MSTN and the MSTN prodomain along with its activity. The objective of this study was to examine the effects of recombinant MSTN prodomains. Individual cultures of the rotifer B. rotundiformis were carried out to determine the effect of recombinant MSTN prodomains (pMALc2x-poMSTNpro and pMALc2x-sMSTNpro) on the pre-reproductive phase, reproductive phase, post-reproductive phase, offspring, lifespan, fecundity, and male ratio. In addition, a population culture of the rotifer was performed to confirm the effects of pMALc2x-poMSTNpro and pMALc2x-sMSTNpro on population growth. The results showed that the rotifer treated with pMALc2x-pMSTNpro had a reduced pre-reproductive phase at higher concentrations (1, 2, and 4 ${\mu}g/ml$) compared to the non-treated control group. Moreover, the pMALc2xsMSTNpro treated rotifer effectively decreased the pre-reproductive phase at a lower concentration (0.25 ${\mu}g/ml$) compared to the pMALc2x-pMSTNpro treated and control group. Interestingly, pMALc2x-poMSTNpro and pMALc2x-sMSTNpro significantly increased the population of $B.$ $rotundiformis$.

• Journal of Life Science
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• v.21 no.8
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• pp.1149-1155
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• 2011

Myostatin (MSTN) belongs to the transforming growth factor-${\beta}$ superfamily or growth and differentiation factor 8 (GDF-8), and functions as a negative regulator of skeletal muscle development and growth. Previous studies in mammals have suggested that myostatin knock-out increased muscle mass and decreased fat content compared to those of the wide type. Recently, several studies on myostatin have beenconducted on the block myostatin signal pathway with myostatin antagonists and the MSTN regulation with RNAi to control myostatin function. This study was performed to analyze growth and muscle alteration of Oncorhychus masou by treatment with recombinant myostatin prodomains derived from fish. We designed myostatin prodomains derived from P. olivaceus (pMALc2x-poMSTNpro) and S. schlegeli (pMALc2x-sMSTNpro) in a pMALc2x expression vector, and then purified the recombinant proteins using affinity chromatography. The purified recombinant proteins were treated in O. masou through an immersion method. Recombinant protein treated groups did not show a significant difference in weight, protein, or lipid composition compared to the control. However, there was a difference in the average number and area for histological analyses in the muscle fiber. At twelve and twenty-two weeks from the initial treatment, there were differences in averagefiber number and area between the 0.05 mg/l treated-group and the control, but the numbers were similar to those of the control during the same time period. At twelve weeks, however, 0.2 mg/l treated-group had an increase in average fiber number and decrease in average fiber area compared to the control. At twenty-two weeks, the pMALc2x-sMSTNpro 0.2 mg/l treated-group was induced and showed a decrease in average fiber number and increase in average fiber area. The results between twelve and twenty-two weeks showed that the fiber numbers had decreased, whereas average fiberarea had increased due to sMSTNpro. It is understood that the sMSTNpro induced only hyperplasia at twelve weeks, after which it induced hypertrophy. Recombinant myostatin prodomains derived from fish may induce hyperplasia and hypertrophy in O. masou depending upon the time that has elapsed.

• Korean Journal of Ichthyology
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• v.24 no.2
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• pp.118-124
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• 2012

The present study was conducted to investigate different gene expression profile between treated poMSTNpro and non-treated in rainbow trout and to identify those genes that are specifically or predominantly expressed in treated poMSTNpro by employing annealing control primer (ACP)-based GeneFishing polymerase chain reaction (PCR). We isolated total RNAs in muscle tissues from the treated poMSTNpro fish by immersion bath technique with fish myostatin prodomain (Paralichthys olivaceus, poMSTNpro) for one month and the other was non-treated poMSTNpro, and synthesized cDNA using annealing control primers (ACP, Seegene, Korea). Using 20 different ACPs for PCR, were cloned sequenced, and analyzed identities of 2 differentially expressed genes (DEGs). According to BLAST analysis, sequences of 2 clones significantly matched database entries and confirmed by semi-quantitative RT-PCR. The functional roles of one up-regulated gene, cytochrome P450 mono-oxygenases 2K1v2 (CYP2K1v2), and one down-regulated gene was Profilin-1 were identified. We identified distinctive gene expression profiles in improved rainbow trout growth by treatment with a fish myostatin prodomain using ACP-based GeneFishing.

• Fisheries and Aquatic Sciences
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• v.10 no.2
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• pp.60-67
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• 2007

Myostatin (MSTN; also known as GDF8) is a member of the transforming growth factor ${\beta}-superfamily$ of proteins. MSTN negatively regulates mammalian skeletal muscle growth and development by inhibiting myoblast proliferation. Mice and cattle possessing mutant MSTN alleles display a 'double muscling' phenotype characterized by extreme skeletal muscle hypertrophy and/or hyperplasia. We isolated the full-length cDNA of a novel MSTN gene from S. schlegeli muscle tissue and examined its expression pattern in various tissues. The full-length gene (GenBank DQ423474) consists of 1941bp with an open reading frame of 1134 bp, encoding 377 amino acids that show 62-92% amino acid similarity to other vertebrate MSTNs. The predicted protein contains a conserved proteolytic cleavage site (RXRR) and nine conserved cysteine residues at the C terminus. RT-PCR revealed that the unprocessed and prodomain myostatin mRNAs were predominantly present in muscle, with limited expression in other tissues. However, the mature myostatin mRNA was highly expressed in brain and muscle, intermediately expressed in the gills, intestine, heart, and kidney, and weakly expressed in the liver and spleen.