HEAT-SHOCK PROTEIN INDUCTION IN MONTASTRAEA-FAVEOLATA AND AIPTASIA-PALLIDA EXPOSED TO ELEVATED-TEMPERATURES

Frequent widespread episodes of coral bleaching have made researchers aware of the sensitivity of reef corals to moderately elevated tempera tures and led us to investigate mechanisms of temperature stress toler ance in this group. One such mechanism may be the induced synthesis of heat shock proteins (hsps), which have been shown to play a role in t hermotolerance in other organisms. However, induced synthesis of hsps in scleractinian corals was not reported until recently. Experiments w ere conducted in which Montastraea faveolata was exposed to high tempe ratures (up to 35 degrees C) for short periods (2 h). Under the condit ions tested, the corals produced seven different hsps with approximate molecular weights of 95, 90, 78, 74, 33, 28, and 27 kDa. Another zoox anthellate species, the sea anemone Aiptasia pallida, also synthesized hsps during temperature stress, but fewer and with different molecula r weights (82, 72, 68, and 48 kDa) than those produced by Montastraea. It now remains to be determined whether hsps are involved in differen ces in thermotolerance and susceptibility to bleaching within and betw een the various species of Montastraea, and between species of reef cn idarians.