Climate changes are not the only consequence of increasing CO2 concentration in the atmosphere. The increase in atmospheric CO2 concentration increases the partial pressure of CO2 (pCO2) in surface waters, reducing the pH of all open waters leading to ocean acidification and hypercapnia. Long term effects of ocean acidification on marine habitats and organisms are not fully investigated, especially not physiological effects on adult fish. Proteomic 2D-gel electrophoresis (2D-GE) is a good approach for comparative analyses giving a specific 2D pattern of expressed proteins. 2D-GE was used to identify differences of pH acclimatization in the gills of two marine fish species, cod (Gadus marhua) and stickleback (Gasterosteus aculeatus), kept in pH 7.7 or 8.1 for three weeks. These species were chosen since they are adapted to different fluctuations in the abiotic environment, the stickleback being more used to changes in the environment. The 2D protein expression pattern gave significantly regulated spots (three in cod and two in stickleback) in low pH exposure groups and four of the protein spots were significantly matched with mass spectrometry identification. The spots detected were: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and hemoglobin beta chain in cod and annexin max3 and proteasome subunit N3 in stickleback. These results show that lower pH leads to a possible stress forcing the fish to up regulate proteins in order to meet new challenges. Additionally, SELDI analysis will be used in order to investigate if the magnitude of protein regulation differs between the investigated species.
Sturve, J., Gunnarsson, F., & Förlin, L., 2010. Effects of low pH on gill protein expression in two fish species, stickleback (Gasterosteus aculeatus) and cod (Gadus morhua). Comparative Biochemistry and Physiology – Part A: Molecular & Integrative Physiology 157(1): S47. Abstract (subscription required).
