All living organisms respond to various physical or chemical stressors by the induction of heat shock protein (HSP). The present study was performed on transgenic Drosophila melanogaster (hsp70-lacZ) Bg(9) in which the transformation vector is inserted with a P-element, the line contains wild-type hsp70 sequence up to the lacZ fusion point. The effect of L-ascorbic acid on the hsp70 expression and tissue damage was studied at the doses of 1, 2, 4, and 8 × 10(-4) g/ml in the third instar larvae of transgenic D. melanogaster (hsp70-lacZ) Bg(9). The larvae were exposed to different doses of L-ascorbic acid for 24 and 48 hours. A dose-dependent significant increase in the hsp70 expression was observed at 2, 4, and 8 × 10(-4) g/ml of L-ascorbic acid for both 24 and 48 hours. The tissue damage was observed only in the 48 hours of exposure and mostly only in the salivary glands of the third instar larvae of transgenic D. melanogaster (hsp70-lacZ) Bg(9). The present study also validates and supports the use of transgenic D. melanogaster (hsp70-lacZ) Bg(9) for the toxicological evaluations.
Keywords: Drosophila melanogaster (hsp70-lacZ) Bg9; L-ascorbic acid; hsp70; trypan blue.