A biomarker model of sublethal genotoxicity (DNA single-strand breaks and adducts) using the sentinel organism Aporrectodea longa in spiked soil.
There is a need to develop risk biomarkers during the remediation of contaminated land. We employed the earthworm, Aporrectodea longa (Ude), to determine whether genotoxicity measures could be applied to this organism's intestinal tissues. Earthworms were added, for 24h or 7 days, to soil samples spiked with benzo[a]pyrene (B[a]P) and/or lindane. After exposure, intestinal tissues (crop/gizzard or intestine) were removed prior to the measurement in disaggregated cells of DNA single-strand breaks (SSBs) by the alkaline comet assay. Damage was quantified by comet tail length (CTL, microm). B[a]P 24-h exposure induced dose-related increases (P<0.0001) in SSBs. Earthworm intestine was significantly (P<0.0001) more susceptible than crop/gizzard to B[a]P and/or lindane. However, both tissues appeared to acquire resistance following 7-day exposure. B[a]P-DNA adducts, measured by (32)P-postlabelling, showed a two-adduct-spot pattern. This preliminary investigation suggests that earthworm tissues may be incorporated into genotoxicity assays to facilitate hazard identification within terrestrial ecosystems.
Martin
Francis L
FL
Department of Biological Sciences, Institute of Environmental and Natural Sciences, Lancaster University, Lancaster LA1 4YQ, UK. f.martin@lancaster.ac.uk
Piearce
Trevor G
TG
Hewer
Alan
A
Phillips
David H
DH
Semple
Kirk T
KT
D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity*; D001673:Biodegradation, Environmental; D020552:Comet Assay; D018736:DNA Adducts; D004249:DNA Damage; D004277:DNA, Single-Stranded; D007422:Intestines; D009835:Oligochaeta; D018570:Risk Assessment; D012989:Soil Pollutants / Q000633:toxicity*; D018675:Toxicity Tests; D043922:Toxicogenetics / Q000379:methods
D018736:DNA Adducts; D004277:DNA, Single-Stranded; D012989:Soil Pollutants; D001564:Benzo(a)pyrene