Development of an in vivo genotoxicity assay using the marine worm Platynereis dumerilii (Polychaeta: Nereidae).
An in vivo genotoxicity test system has been developed using the embryo-larval stages of the marine annelid, Platynereis dumerilii (Polychaeta: Nereidae). This species is representative of an ecologically important group of marine invertebrates, it is amenable to laboratory culture and has a well defined and stable karyotype (2n=28) which is suitable for the analysis of a range of cytogenetic endpoints, including chromosomal aberrations (CAs) and sister chromatid exchanges (SCEs). An evaluation of the cell cycle kinetics using the embryo-larval stages allowed selection of exposure times for cytogenetic work. Subsequently, 12-h-old embryos were exposed to reference mutagens, dissolved in sea water, in the presence of 5-bromodeoxyuridine (BrdU) for 12 h (SCE analysis) or 8 h (CA analysis) at 15 +/- 1 degree C, by which time they had reached the first larval stage (20-24h). Dose response-relationships for cytotoxicity, SCEs and CAs were observed for both direct acting mutagens (methyl methanesulfonate, mitomycin C) and mutagens which require metabolic activation (cyclophosphamide, benzo[a]pyrene). The sensitivity of the embryo-larval stages of P. dumerilii to both direct and indirect acting mutagens, their suitability for laboratory culture, together with the presence of a good karyotype and chromosome morphology for cytogenetic analyses, makes this species a potentially valuable in vivo model for marine genotoxicity testing.
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Brixham Environmental Laboratory, ZENECA Limited, Brixham, Devon, UK.
Hutchinson
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TH
Mackay
J M
JM
Elliott
B M
BM
Dixon
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DR
D000818:Animals; D002869:Chromosome Aberrations; D009152:Mutagenicity Tests / Q000379:methods*; D011077:Polychaeta / Q000187:drug effects*; D012854:Sister Chromatid Exchange / Q000187:drug effects