| Summary: | 碩士 === 國立海洋大學 === 水產養殖學系 === 89 === Myostatin (GDF-8; MSTN), a recently identified member of transforming growth factor (TGF-b) superfamily, is expressed predominantly in skeletal muscle and may be a key negative regulator of skeletal muscle development and growth. Furthermore, mice in which the myostatin gene was inactivated (non-functional via gene knockout) have considerably more skeletal muscle than wild type controls. The regulator of muscle development and growth in lower vertebrates and invertebrates still is poorly understood. In the present study, we have utilized reverse transcription polymerase chain reaction (RT-PCR) with degenerated primers to amplify partial myostatin encoding sequence from various aquatic species (such as zebrafish, tilapia, grouper, small abalone). Identities of nucleic acid level (sequence 901-1,125bp) in aquatic organisms range from 99.11% to 73.78% to the comparable same coding region myostatin of the member, such as human, mouse, baboon, bovine, porcine, ovine, chicken, and turkey respectively. Not unexpectedly, the similarity of the deduced amino sequence of fish and shellfish are approximately 100% to 90.54 % identical to each other as well as to the comparable coding region sequence (301-374 a.a.) of other members of the myostatin family. The present studies suggest that double muscle gene (myostatin) exist in both finfish and invertebrates, such as abalone. The full-length cDNA of myostatin in zebrafish was cloned by using RACE method (rapid amplification of cDNA end method), it contains 2179 bp consists of 80 bp in the 5’-untranslation region, 974 bp in the 3’-untranslation region, and 1125 bp corded for 375 residues in the cording region. The expression of myostatin is locating at the developmental somites of 18 p.c. zebrafish embryo by whole-mount in situ hybridization analysis. The limited expression of myostatin as early as 4-hour post coitum by RT-PCR analysis.
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