The heat shock response in the copepod Eurytemora affinis (POPPE)

Abstract

The heat-shock or stress response is a ubiquitous cellular response to physiological stress. The copepod Eurytemora affinis a year-round inhabitant of the Chesapeake Bay when exposed to elevated temperatures for several hours showed alterations in its pattern of protein synthesis. Newly synthesized proteins or proteins synthesized in greater amounts, both known as heat shock proteins or HSPs, were characterized by labelling them with [ 35S]methionine, separating them by 1 and 2-dimensional gel electrophoresis and identifying them by autoradiography. Copepods raised at 4 and 15°C and heat shocked had different patterns of protein synthesis than those raised at 20°C. Time-course experiments showed that these HSPs persisted for several hours under continuing heat shock. There was some difference in the pattern of heat-shock protein synthesis between males and females. Chlorine residuals and tributyltin (TBT) also induced the heat shock response but the proteins induced were different. Algal parasites seemed to induced a similar set of HSPs to those induced by chlorine and tributyltin. However, periodic exposure of copepods to cold temperatures did not cause the induction of any HSPs.