title: Cathepsin B and glutathione peroxidase show differing transcriptional responses in the grass shrimp, Palaemonetes pugio following exposure to three xenobiotics.
abstract: The common molecular biology techniques, suppressive-subtractive hybridization (SSH) and semi-quantitative real-time PCR (SQRT-PCR), were used to identify differentially expressed genes in the grass shrimp, Palaemonetes pugio following exposure to three different xenobiotics. Lab-acclimated adult male grass shrimp were exposed to empirically derived 96-hr male-specific LC50 concentrations of fipronil (FP, a phenylpyrazole GABA disrupting pesticide), endosulfan (ES, a cyclodiene GABA disrupting pesticide), or cadmium (Cd), as well as a control (CC). An SSH gene expression library was constructed from surviving shrimp from the fipronil and control exposures. Clones obtained by SSH were identified by searching against the NCBI website. A total of 42 genes were identified that were up-regulated by FP exposure, and 47 that were down-regulated. A subset of the affected genes was tested with SQRT-PCR to verify responsiveness to fipronil, as well as to endosulfan and cadmium. Two genes showed strong and significant responses to the exposures: glutathione peroxidase was significantly up-regulated by all three exposures, while Cathepsin B was strongly responsive to the two pesticides, but not to cadmium.
authors.affiliation: Department of Environmental Health Sciences, Norman J. Arnold School of Public Health, University of South Carolina, Columbia, South Carolina 29208, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Griffitt
authors.forename: G T
authors.initials: GT
authors.lastname: Chandler
authors.forename: T W
authors.initials: TW
authors.lastname: Greig
authors.forename: J M
authors.initials: JM
authors.lastname: Quattro
mesh_terms: D000818:Animals; D002104:Cadmium / Q000633:toxicity; D002401:Cathepsin B / Q000235:genetics*; D004726:Endosulfan / Q000633:toxicity; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005979:Glutathione Peroxidase / Q000235:genetics*; D007928:Lethal Dose 50; D008297:Male; D033541:Palaemonidae / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D011720:Pyrazoles / Q000633:toxicity; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D015262:Xenobiotics / Q000633:toxicity*
chemical_list: D011720:Pyrazoles; D015262:Xenobiotics; D002104:Cadmium; D005979:Glutathione Peroxidase; D002401:Cathepsin B; D004726:Endosulfan; C082360:fipronil