Are there salinity stress proteins?

To establish whether osmotic stress can be separated from possible toxicant stress in Eurytemora affinis, protein synthesis was analyzed under various conditions of temperature and osmotic stress. Individual adult copepods raised at 10 ppt and 15 °C were exposed for 5 h to different temperature and salinity regimes. Newly synthesized proteins were separated and identified using SDS-PAGE and autoradiography. Copepods exposed to lower (2 and 5 ppt) and higher (15 and 20 ppt) salinities showed differences in the up- and down-regulation of specific proteins. Concurrent heat stress changed these protein patterns. These results suggest that protein profiles might be used to distinguish the effect of toxicants in a salinity gradient such as the Chesapeake Bay or in the Baltic region.