Plant, Animal & Microbe Genomes X Conference

January 12-16, 2002
Town & Country Convention Center
San Diego, CA

Poster: Aquaculture
          

MOLECULAR CHARACTERIZATION AND DIFFERENTIAL EXPRESSION OF THE MYOSTATIN GENE IN CHANNEL CATFISH (ICTALURUS PUNCTATUS)

¹ The Fish Molecular Genetics and Biotechnology Laboratory, Department of Fisheries and Allied Aquacultures and Program of Cell and Molecular Biosciences, Auburn University, Auburn, AL 36849, USA

Myostatin is a recently discovered gene that inhibits muscle growth. In the present study, we characterized the myostatin locus and its expression in channel catfish (Ictalurus punctatus). The genomic DNA and cDNA encoding the channel catfish myostatin were cloned and sequenced. The myostatin gene has three exons encoding a protein of 389 amino acids. Comparison of the genomic sequences with those of the cDNA revealed that the myostatin cDNA was 1,673 base pair (bp) long with a 5’-untranslated region (UTR) and 3’-UTR of 180 bp and 323 bp, respectively. The deduced amino acid sequences of the catfish myostatin is highly conserved with those of other organisms. The myostatin locus is highly polymorphic in channel catfish because of the presence of several microsatellites and single nucleotide polymorphic sites (SNPs). Particularly worthwhile mentioning is the presence of polymorphic (CAG) repeats within the first exon, making the polyglutamine tract variable both within channel catfish and through evolution in different species. The biological importance of expansion of the polyglutamine tract is not known at present. The myostatin gene was expressed in various tissues and developmental stages at differential levels, suggesting complex regulation of this gene and perhaps roles for myostatin in addition to those originally suggested.