Characteristics and Genetic Analysis of Fish Transferrin

Abstract

Most studies of fish transferrins focus on their potential for discriminating genetic populations within species. Transferrin genes are polymorphic in most species of fish.There are three transferrin genotypes (A, B, andC) in coho salmon, and C type coho salmon is the most resistant to bacterial kidney disease.
Fish transferrins have the same characteristics as the higher vertebrates, in such points as duplicated structure, conservative iron binding regions and cystein residues. The homology of amino acid sequences of medaka and Atlantic salmon transferrins and other members of the transfenin family range from30 to 50%. Medaka transferrin gene was consists of 17 exons, the same number as the higher vertebrates transferrin family genes. However, intron sizes of medaka transferrin gene are smaller than those of human transferrin gene.There are several transcriptional regulatory elements on the 5'up-stream region of the medaka transferrin gene. Medaka and Atlantic salmon transferrins are transcribed mostly in the liver.