We examined the effects of cadmium exposure and various temperature stress on the expression of Pardosa astrigera heat shock protein 70 (HSP70). To do this, P. astrigera HSP70 gene was cloned and its sequence determined. Female spiders collected from non-contaminated region were exposed to 40mM CdCl2 for 2, 4 and 6 weeks by dietary uptake. At the end of every 2, 4 and 6 weeks of exposure, a batch of 5 spiders was collected and total RNA was extracted from each batch of whole bodies. Female spiders were also exposed to different temperatures (20, 25, 30 and 35℃) for 3h and RNA extracted likewise. Transcription profiles of HSP70 in response to cadmium and temperature were determined by quantitative real-time PCR using 18S rRNA as reference gene for data normalization. HSP70 transcription gradually increased during 2,4 and 6 weeks of exposure to cadmium. In particular, the expression level at 6-week exposure was 3.4-fold higher than that of untreated control. In the temperature response, an increased expression of HSP70 was also observed as temperature increased up to 30℃ and then slightly decreased at 35℃. The expression level at 30℃ was 2.3-fold higher than that of 25℃. Taken together, HSP70 gene appears to be up-regulated by general stress factors including cadmium exposure and temperature increase.

• Min-Hee Koh(School of Agricultural Biotechnology, Seoul National University)
• Si Hyeock Lee(School of Agricultural Biotechnology, Seoul National University)