Transgenic lines of insect resistant cabbage (Brassica oleracea var. capitata) expressing Cry1Ac1 protein has been developed to control diamondback moth (Plutella xylostella). The potential adverse effects of Bt crops on non-target arthropod herbivores and predators are major concerns. We conducted a tritrophic bioassay to study the ecological impacts of insecticidal transgenic cabbage on the wolf spider (Pardosa astrigera), a non-target generalist predator. First, we measured the levels of Cry1Ac1 proteins in fruit flies that were fed with the transgenic cabbage as well as those levels in the wolf spiders preying on the Bt cabbage-fed fruit flies using enzyme linked immunosorbent assay (ELISA). Cry1Ac1 proteins were detected in the Bt cabbage fed fruit flies and also in the wolf spiders after preying on Bt cabbage-fed fruit flies. Second, we compared the life history characteristics of the wolf spiders preying on the Bt or non-Bt cabbage. Growth, development time and survival of the wolf spiders were not significantly different between Bt and non-Bt cabbage. Although the wolf spiders were exposed to Cry1Ac1 protein via feeding on the preys containing Cry1Ac1 proteins, their growth and survival was not significantly affected.

We investigated the effects of cadmium exposure and various stress on the transcription of heat shock protein 70 and 82 (HSP70 and HSP82) from Pardosa astrigera wolf spider. To do this, P. astrigera HSP70 and HSP82 genes were cloned and its full-length sequence determined. Female spiders were long-term exposed to cadmium or to polychlorinated biphenyl (PCB) for 2, 4 and 6 weeks and short-term exposed to endosulfan by dietary uptake. Female spiders were also exposed to various temperatures. HSP82 did not show a clear tendency of transcription induction following exposure to cadmium. On the contrary, HSP70 transcription gradually increased during the exposure to 2, 20 and 40 mM of cadmium for 2, 4 and 6 weeks. Transcript level of HSP70 was not significantly changed by endosulfan and PCB exposure. In the short-term (3 hr) temperature exposure, an increased expression of HSP70 was observed under the heat shock to 30°C and then slightly decreased at 35°C. However, induction of HSP70 transcription was not observed during the long-term (7 days) temperature exposure. Taken together, HSP70 gene appears to be up-regulated by cadmium in a time-dependent manner but little affected by other potential contaminants. Analysis of HSP70 transcript levels in P. astrigera collected from various fields revealed that levels of cadmium concentration were well correlated with HSP70 transcript levels (r2 = 0.76). Taken together, it was suggested that transcript level of HSP70 could be useful as a biomarker for the long-term cadmium exposure of P. astrigera.

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.

별늑대거미 암컷 체내 카드뮴양이 알 크기에 미치는 영향을 파악하기 위해서 본 실험이 수행되었다. 2007년 9월 도심지, 농경지, 폐광, 제련소지역의 7개 지역에서 알집을 달고 있는 별늑대거미 암컷성체를 채집하여, 알집내 알 크기와 암성체내 카드뮴 양을 측정하였다. 2007년 11월 별늑대거미 아성체 및 성체 암수 각각 50마리씩을 동일 장소에서 채집하여 1달간 개체사육을 한 후 교미시켰다. 카드뮴 처리 노랑초파리(Drosophila melanogaster)와 무처리 노랑초파리의 공급 비율을 달리하여 3일 간격으로 4마리씩 먹이로 제공하였다. 교미 후 생성된 알집 내 알 크기와 암성체내 카드뮴 양을 측정하였다. 체내 카드뮴 양과 알 크기 관계는 선형회귀분석을 이용하였다. 야외 개체의 별늑대거미 알 크기는 0.14-0.21mm3를 보였고, 체내 카드뮴양은 4-26mg/kg의 범위를 나타내었으며, 체내 카드뮴양이 많을수록 알 크기가 증가하였다 (r2=0.87). 실내실험에서는 실험조건별로 알 크기 및 체내 카드뮴 양에 많은 차이를 보였다. 카드뮴 무처리 초파리를 먹인 별늑대거미 암컷의 체내 카드뮴 양은 4.72-19.52mg/kg 이었으며, 알 크기는 0.38-0.41mm3이었다. 카드뮴 무처리 초파리와 처리 초파리를 1:1의 비율로 먹인 별늑대거미 암컷 체내 카드뮴 양은 104.82-167.41mg/kg이었으며, 알의 크기는 0.46-0.48mm3를 보였다. 카드뮴 처리된 초파리만 먹인 별늑대거미 암컷 체내 카드뮴 양은 165.63-204.57mg/kg이었으며, 알 크기는 0.47-0.50mm3를 보였다. 체내 카드뮴 양이 많을수록 알 크기가 증가하였다 (r2=0.83).