Expression of glutathione S-transferase (GST) genes in the marine copepod Tigriopus japonicus exposed to trace metals.
The intertidal copepod, Tigriopus japonicus has been recognized as a potential model species for marine pollution toxicity testing. Toxicity ranges of several biocides, endocrine-disrupting chemicals (EDCs), and trace metals are known in T. japonicus. A large number of expressed sequence tags (ESTs) and genomic DNA are also sequenced from T. japonicus. In this study, expression of ten glutathione S-transferase (GST) genes was studied in the copepods exposed to trace metals. Expression of these genes was also studied against exposure to hydrogen peroxide (H(2)O(2)) used as a positive control with prooxidant activity. Of all genes, expression of GST-Sigma (GSTS) was highly upregulated in H(2)O(2) as well as trace metal-exposed copepods. In the time-course study, expression of GSTS mRNA was more consistent compared to other GSTs such as GST-Omega, GST-Delta1, GST-Theta3 or microsomal GST1 (mGST1). GSTS is predominantly reported from the insects. Coupled with the previous study of the in vitro antioxidant role of T. japonicus GSTS, these findings imply an antioxidant role for GSTS and highlight its importance as a biomarker of exposure to trace metals in T. japonicus. However, further validation and field trials would be necessary to propose GSTS gene expression as biomarker of exposure to trace metals, as for some trace metals such as silver the response was not consistent in concentration and time-series exposure experiments.
Lee
Kyun-Woo
KW
The Research Institute for Natural Sciences, Hanyang University, Seoul 133-791, South Korea.
Raisuddin
Sheikh
S
Rhee
Jae-Sung
JS
Hwang
Dae-Sik
DS
Yu
In Tag
IT
Lee
Young-Mi
YM
Park
Heum Gi
HG
Lee
Jae-Seong
JS
D000818:Animals; D033342:Copepoda / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D004784:Environmental Monitoring / Q000379:methods*; D020224:Expressed Sequence Tags; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling / Q000379:methods; D005982:Glutathione Transferase / Q000096:biosynthesis* / Q000235:genetics; D006861:Hydrogen Peroxide / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014131:Trace Elements / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity
D012333:RNA, Messenger; D014131:Trace Elements; D014874:Water Pollutants, Chemical; D006861:Hydrogen Peroxide; D005982:Glutathione Transferase