THERMOTOLERANCE AND THE HEAT SHOCK RESPONSE IN MUSCA DOMESTICA

摘要

The relative abilities of larvae, pupae and adults of a laboratory population of the tropical housefly, Musca domestica, to withstand increasing environmental temperature (37 degrees C to 48 degrees C) were studied in terms of per cent adult survival/emergence. Pupal stage appeared best adapted to higher temperatures (44 degrees C or 46 degrees C), exhibiting significantly higher per cent survival as adult. In contrast, the tolerance of adult flies to higher temperature shock (44 degrees C or 46 degrees C) was poorer. A short period (1 h) of pre-conditioning at 37 degrees C resulted in the development of considerable thermotolerance to higher temperatures (42 degrees C to 46 degrees C). Eight prominent heat shock polypeptides of approximate molecular weights 80, 73, 70, 64, 30, 28, 26 and 20.5 kD were induced upon in vitro exposure of the larval or adult tissues at 42 degrees C to 46 degrees C temperature. The 70 kD polypeptide appeared predominant in all the tissues at all temperatures. The pattern of expression (number and relative intensity) of various heat shock proteins at different temperatures of heat shock appeared to be related with the observed per cent values of adult survival at corresponding temperatures. Possible role of the heat-inducible proteins in thermotolerance and adaptation to severe seasonal fluctuations in environmental temperature has been discussed. [References: 29]