Cadmium (Cd), a heavy metal found in the aquatic environment, accumulates in organisms through the food chain. In the study, we investigated the survival rates, measurement of body Cd levels, and expression analysis of the stress response genes (Heat shock protein 70: HSP70 and Heat shock protein 60: HSP60) and antioxidant enzyme Glutathione S-Transferases (GST) on benthic oligochaete worm Tubifex tubifex exposed three concentrations of Cd, to analyze the bioaccumulation and changes of stress gene expressions to exposure toxicity of the Cd-spiked sediment. Survival rates of T. tubifex exposed to the Cdspiked sediment were 93% at 0.4 mg kg-1 Cd, 96% at 1.87 mg kg-1 Cd, and 93% at 6.09 mg kg-1 Cd for 10 days. Cd concentration in the body of T. tubifex was higher than that in the sediment. After Cd exposures for 10 days, the body Cd levels were 18.4 mg kg-1, 13.06 mg kg-1, and 79.11 mg kg-1 at exposed three concentrations of Cd, respectively. Upregulation of HSP70 gene expression was observed at all concentrations of exposed Cd as a time-dependent manner, whereas transcriptional expression of the HSP60 gene increased as a timedependent manner in T. tubifex exposed to the relative high concentration (6.09 mg kg-1) of Cd. However, GST gene expression increased on day 1 at all concentrations after Cd exposures, and then downregulated until 10 days. These results indicate to ecotoxicological and molecular effects in benthic oligochaete worm T. tubifex to Cd-spiked sediment and provide the basic information for the utilization of environmental toxicity assessment using the T. tubifex as a aquatic pollution indicator species.

서 론
재료 및 방 법
    1. 실험생물 및 퇴적물
    2. 만성 독성노출 실험 조건
    3. 생존율 관찰 및 생물농축 측정
    4. HSP60, HSP70, GST 유전자 발현
    5. 통계 분석
결과 및 고 찰
적 요
REFERENCES

• 김지훈(전남대학교 해양융합과학과) | Ji-Hoon Kim (Department of Ocean Integrated Science, Chonnam National University, Yeosu 59626, Republic of Korea)
• 김원석(전남대학교 해양융합과학과) | Won-Seok Kim (Department of Ocean Integrated Science, Chonnam National University, Yeosu 59626, Republic of Korea)
• 박기연(전남대학교 수산과학연구소) | Kiyun Park (Science Institute, Chonnam National University, Yeosu 59626, Republic of Korea)
• 곽인실(전남대학교 해양융합과학과, 전남대학교 수산과학연구소) | Ihn-Sil Kwak (Department of Ocean Integrated Science, Chonnam National University, Yeosu 59626, Republic of Korea, Fisheries Science Institute, Chonnam National University, Yeosu 59626, Republic of Korea) Corresponding author