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Use of Early Life-Stages of Zebrafish to Assess Toxicity of Sediments Contaminated by Organotin Compounds

Sahoo, Tarini P., Oikari, Aimo
Soil & sediment contamination 2016 v.25 no.2 pp. 117-132
Danio rerio, aromatase, bioluminescence, brain, dose response, heart rate, lakes, sediment contamination, sediments, toxicity, tributyltin, vitellogenin, Finland
This study examined the response of early life-stages (ELS) of zebrafish to organotin-contaminated sediment from Lake Huruslahti (HL) in Central Finland. A dilution series (0, 10, 33, and 100%) of the native (HL) and the sediment spiked with tributyltin (TBT) determined a dose-response of zebrafish ELS to organotin-contaminated sediment. Sediment elutriates were assessed by bacterial bioluminescence assay and microscopical pathologies of 1–3 days post-fertilization zebrafish (1–3dpfZF). Brain aromatase (cyp19a1b) and tissue vitellogenin (vtg1) were assayed from early-juvenile zebrafish (20dpfZF) exposed to intact sediment. In vivo modulation of cyp19a1b and vtg1 transcripts in 20dpfZF was targeted to screen potential sediment contamination by TBT, an anti-estrogenic chemical. Bioluminescence assay (EC50 ₃₀ₘᵢₙ ₌ 34.6% of HL-100) determined that the HL-100 elutriate was toxic. Exposed developing embryos (1–3dpf) showed toxicities, including lowered heart rate. Results showed down-regulation of cyp19a1b and up-regulation of vtg1 in 20dpfZF exposed to TBT-spiked sediment (185–1620 µg/kg d.w.).