Aim: 

Antarctic marine environment is characterised by increased oxygen concentration, correlated to low temperature of waters (-1,9°C). In these conditions, reactive oxygen specie (ROS) formation is favoured. The organisms living in this environment perform strong cellular antioxidant homeostatic control, mainly inducing antioxidant enzymes. Among these, glutathione peroxidase (GPX) is an ubiquitous cytosolic enzyme which catalyzes the reduction of hydrogen peroxide and other organic peroxides. In the present study we have characterised the cDNA sequence of GPX from the Antarctic fish Trematomus eulepidotus.

Methods: 

Specimens of this teleost were sampled in the Ross Sea (Terra Nova Bay, 74°42'S, 164°7'E) during the XXI Italian Antarctic Expedition. cDNA sequence of GPX has been obtained from hepatic tissue by a combination of RT-PCR, 3'RACE and 5'RACE techniques. The obtained nucleotide and amino acid sequences were compared to those of other teleost GPXs available in GenBank, SwissProt and published literature.

Results: 

The results shown high identity and similarity levels. The knowledge of cDNA sequence allowed to design specific oligonucleotide primers for the quantification of mRNA levels in different tissues by semi-quantitative RT-PCR analyses.

Conclusion: 

The obtained results are the first data about GPX gene induction in Antarctic teleost species and act as start-up for further studies on physiological antioxidant responses to the high oxygen concentration Antarctic environment.

This research was partly supported by the Italian National Program for Antarctic Research (PNRA).