Abstract

Myostatin is a negative regulatory protein of growth and muscular development in several vertebrate species. However, for molluscs there is currently little information about the structure and function of the myostatin gene (MSTN), and its implications at the physiological and ecological levels. The aims of this study were to molecularly characterize the MSTN gene in Argopecten purpuratus (ApMSTN) and analyse gene expression patterns between wild and hatchery-bred populations. A complete ApMSTN sequence of 1,062 base pairs (bp) was obtained, which encodes a 354 amino acid. The amino acid sequence indicated a characteristic proteolytic processing site of MSTN (RXXR), nine conserved cysteine residues, and 344 and 919 bp corresponding to 5'UTR and 3'UTR, respectively. Furthermore, ApMSTN sequences revealed a total of four single-nucleotide polymorphisms (SNPs). Of these, SNP -186G/A was only found in the wild population, while SNP -305A/T was found in both populations. SNP +779A/G, located in the coding region, was identified in wild scallops. In contrast, mutations identified in the 3'UTR were only found in hatchery-bred individuals. An upregulated expression pattern of ApMSTN was mainly associated with the adductor muscle of hatchery-bred scallops. The molecular differences found for the ApMSTN gene in A. purpuratus provide relevant information for future evaluations on the ecological implications of this gene.