중금속은 다양한 경로를 통해 환경 중 배출되어 서식 생물에 노출되며 체내 다양한 생리학적 불균형을 유도한다. 본 연구에서는 수서생물지표종으로 이용되는 깔따구 (Chironomus riparius)를 이용하여 야외 중금속 (Al, Aluminum; Cr, Chromium; Cu, copper; Mn, Manganese; Zn, Zinc) 농도 노출에 따른 다양한 분자발현 반응과 상관성을 분석하였다. 생물 체내 분자 반응을 관찰하기 위해 heat shock protein 40, 70, 90 (HSP40, 70, 90), cytochrome 450 (CYP450), Glutathione S-transferase (GST) and Serine-type endopeptidase (SP)를 이용하였다. 그 결과, 스트레스 분자마 커로 이용되는 HSPs 유전자들은 중금속 노출된 개체들에서 대조군보다 높은 경향을 보였으며 Cu 노출 시 가장 높은 발현을 나타냈다. 해독에 관여하는 CYP450과 GST 유전자 발현 결과, Cr과 Cu에서는 다른 노출군에 비해 높은 발현 경향을 나타냈다. SP 유전자 발현 결과 Al을 제외한 모든 노출군이 대조군과 유사한 발현 패턴을 보였다. 이와 같은 연구 결과는 실내에서 환경 중 존재하는 실제 농도를 반영한 독성실험을 통해 노출물질과 농도에 따라 특이적으로 발현하는 분자마커 패턴을 보고하였다. 또한, 수생태계로 유입되는 중금속이 하천에 서식하는 생물에 주는 유해 영향에 대한 정보와 분자 지표 유전자들의 현장 적용 가능성을 보여준다.

We investigate that the impact of freshwater organism exposed to the salinity environment by the frequent rainfall following climate change. To evaluate the stress response following salinity exposure, we assessed the survival rate, molting success rate, the developmental period and mouthpart deformities in Chironomus riparius. In addition, we measured the molecular responses of biomarker gene, gene expression of heat shock protein 70 (HSP70) in C. riparius exposed to salinity after 96 hour. The C. riparius survival rates were showed on time dependent manner and not observed survival organisms above 15 psu at day 4. The pupation and emergence of C. riparius were not seen above 15 psu, and the molting success rate was less than 20% at 10 psu. The developmental retardation of C. riparius was well observed in the pupation and emergence period and was delayed by 4 days at 10 psu compared to the control and 5 psu. The mouthpart deformities after salinity exposure at 96 or 72 hour were observed at 10 psu and 15 psu. The expression of C. riparius HSP70 level was significantly increased exposure to 5 psu and 10 psu. Thus, salinity has been caused to be various ecotoxicological and molecular stress responses on freshwater organisms similar to harmful substances such as EDCs and so on.

Chironomus riparius, a non-biting midge (Chironomidae, Diptera), is extensively used in aquatic ecotoxicological studies for assessing acute and sub-lethal toxicities of contaminated sediments and for water monitoring due to their widespread occurrence, short life-cycle, easy to be reared in the laboratory, physiological tolerance to various environmental conditions. To date, the endpoints used for monitoring such effects in C. riparius are based on a small number of specific biomarkers and measurements of organism level effects, such as survival and reproduction. Genomic-based techniques based on expression analysis of genes are important tools for investigating molecular level effects caused by exposure to environmental pollutants, which will provide the ability to detect mechanisms of action and subsequent adverse cellular level effects and associated with different types of toxicity. As a pre-requisite for genomic based ecotoxicological studies knowledge on the C. riparius transcriptome is important but despite its ecotoxicological importance, no large scale transcriptome analysis of C. riparius has been done so far. Therefore, to gain a better understanding of C. riparius transcriptome, we recently developed Expressed Sequence Tags (ESTs) sequencing project on C. riparius larvae using 454 pyrosequencing. Sequencing runs, using normalized cDNA collections from fourth instar larvae, yielded 20,020 expressed sequence tags, which were assembled into 8,565 contigs and 11,455 singletons. Sequence analysis was performed by BlastX search against the National Center for Biotechnology Information (NCBI) nucleotide (nr) and uniprot protein database. Based on the gene ontology classifications, 24% (E-value ≤1-5) of the sequences had known gene functions, 24% had unknown functions and 52% of sequences did not match any known sequences in the existing database. Sequence comparison revealed 81% of the genes have homologous genes among other insects belonging to the order Diptera providing tools for comparative genome analyses. Targeted searches using these annotations identified genes associated with essential metabolic pathways, signaling pathways, detoxification of toxic metabolites and stress response genes of ecotoxicological interest. The results obtained from this study would eventually make ecotoxicogenomics possible in a truly environmentally relevant species, C. riparius. Various C. riparius ecotoxicity studies using stress response genes developed from 454 sequencing will be presented in the conference.

실내에서 사육된 C. riparius를 대상으로 내분비계 교란물질인 DEHP를 처리하여 노출시간에 따른 기형발생률과 발생한 기형의 유형을 세분화하였다. 하순기절 구조별 기형발생률은 MLT (medial lateral tooth)에서 가장 높았고 그 다음이 LT (lateral tooth), MIX 순으로 높게 나타났다. 비처리군과 처리군 모두 MLT 단독의 기형이 가장 많았다. 하순기절의 기형유형은 여섯 가지로 세분화하였다. 발생빈도가 높은 기형유형은

The exposed strain of C. riparius treated with di (ethyl- hexyl)-phthalate (DEHP) did not result in a consistent relationship between mortality or sex ratio and chemical concentrations. And after treating with DEHP, the emergent female from the exposed st

Development of the fourth-instar larvae of Chironomus riparius has a sensitive to ecdysteroid hormones. The 2D/E gel analysis for polypeptide expression reflecting early-ecdysterone inducible gene has conducted the emerged female from larval phase exposur

The 2D/E gel analysis for polypeptide expression reflecting I-18 C gene (early-ecdysterone inducible gene) has conducted the emerged C. riparius adults from larval phase exposure to tebufenozide acting as an ecdysteroidal molting hormone. Control group, t

한국산 요시마쯔깔따구(Chironomus yoshimatsui)의 세 가지 중금속(납, 카드뮴, 수은)에 대한 급성독성 및 행동 독성을 외국 표준 실험 종인 리파리깔따구(C. riparius)와 비교하였다 48시간 및 96시간 동안 수중 노출(water-only exposure)을 시킨 후 두 가지 실험종의 반수치사농도(LC50)및 깔따구의 유영 능력 감소에 영향을 주는 농도(EC50)를 바탕으로 두 실험 종간의 차이를 살펴보았다. 카드뮴

Due to the fourth-instar larvae of C. riparius have a sensitive to ecdysteroidal molting hormones for the life cycle developments, accordingly the emerged adult affected corresponding to larval phase's environments. The emerged female from larval phase ex

The effects of Di (2-ethylhexyl) phthalate (DEHP) on the fourth instar larvae of Chironomus riparius were tested in the laboratory. Employing a waterreplacement exposure setup, chironomids were subjected to various concentrations. In the most treatments m

탈피호르몬의 작용을 방해하는 농약제인 tebufenozide 를 알에서 부화한 지 7일째의 C. riparius에 처리하여 성충이 될 때까지의 생장과정을 연구하였다. C. riparius 에 control, 10 μg L-1, 30 μg L-1, 60 μg L-1와 100 μg L-1의 농도로 약제를 처리하였다. 전체적으로 약제를 처리한 하루 후인 D12에 16%가 치사