Jg. Sorensen et V. Loeschcke, Larval crowding in Drosophila melanogaster induces Hsp70 expression, and leads to increased adult longevity and adult thermal stress resistance, J INSECT PH, 47(11), 2001, pp. 1301-1307
In this study we show for the first time that moderate high larval density,
induces Hsp70 expression in Drosophila melanogaster larvae. Larval crowdin
g led to both increased mean and maximal longevity,in adults of both sexes.
Two different measures of heat-stress resistance increased in adult flies
developed at high density compared to flies developed at low density. The h
ardening-like effect of high larval density carried over to the adult life
stage. The hardening memory (the period of increased resistance after harde
ning) was long compared to hardening of adult flies, and possibly lasts thr
oughout life. The increase in resistance in adults following development at
high larval density seemed not to be connected to Hsp70 itself, since Hsp7
0 expression level in adult flies after hardening was independent of whethe
r larvae developed at low or high densities. More likely, Hsp70 may be one
of many components of the stress response resulting in hardening. (C) 2001
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