Gene expression of hsp70 of the diamondback moth, Plutella xylostella (Lepidoptera: Yponomeutidae), in response to heat shock and insecticides

The heat shock protein gene, hsp70, was cloned and sequenced from the diamondback moth, Plutella xylostella (L.). cDNA sequence analysis revealed a 1,992 bp-long open reading frame, which encodes a protein with a calculated molecular weight of 72.2 kDa. Results of Southern blot analysis suggested the presence of multiple copies of the hsp70 family in the genome. Increased expression of hsp70 was observed in fourth instar larvae exposed to 42 degrees C. No significant up-regulation of hsp70 expression was observed when fourth instar larvae were treated with sub-lethal doses of insecticides, chlorfenapyr, permethrin, and acephate. These results suggest that hsp70 cloned in the present study is less sensitive to insecticides.