Maria Rosaria Coscia
Antarctic fish are an extraordinary example of adaptation to the extreme cold environment where significant gene modification events have played a crucial role. Due to the well-documented plasticity of its gene locus, the Immunoglobulin (Ig) molecule represents a valuable model for understanding evolutionary modifications occurred in the Antarctic teleost species. We have reported, in a recent paper, the first identification of IgT heavy chain gene in the Antarctic Notothenioid teleost Trematomus bernacchii; it encodes three differently sized IgT transcript variants, named Long, Short and Shortest. Genomic analysis revealed that, within the intron between the exons coding for the entire first and second constant domains, a reminiscence of the ancestral second exon was present. We have disclosed an unsuspected complexity of the Ig genes of Antarctic fish, reinforcing the general concept of a high variability of these genes across teleost species.