Fish Growth Hormone Genes: Structure and Divergence
The review provides information about the structure of growth hormone genes (GHG) in fish and the divergence of coding, intron, and adjacent flanking regions; original data, obtained in our laboratory, is also considered. In most fish species, GHG is represented by a single copy, while some of taxonomic groups have two paralogous genes. Coding sequences of GHGs are conservative. The gene length variations depend on the length of non-coding introns and flanking regions. The divergence rate of gene sequences varies not only between different taxonomic groups, but also in time of divergence within groups. In flanking regions, only regulatory elements are conservative.