Developmental toxicity and DNA damage from exposure to parking lot runoff retention pond samples in the Japanese medaka (Oryzias latipes)

Abstract

Parking lot runoff retention ponds (PLRRP) receive significant chemical input, but the biological effects of parking lot runoff are not well understood. We used the Japanese medaka (Oryzias latipes) as a model to study the toxicity of water and sediment samples from a PLRRP in Morehead City, NC. Medaka exposed in ovo to a dilution series of PLRRP water had increased odds of death before hatching, but not teratogenesis or delayed hatching. Next, we adapted a long-amplicon quantitative PCR (LA-QPCR) assay for DNA damage for use with the Japanese medaka. We employed LA-QPCR to test the hypotheses that PLRRP water and sediments would cause nuclear and mitochondrial DNA damage with and without full-spectrum, natural solar radiation. Fluoranthene with and without natural sunlight was a positive control for phototoxic polycyclic aromatic hydrocarbon-induced DNA damage. Fluoranthene exposure did not result in detectable DNA damage by itself, but in combination with sunlight caused significant DNA damage to both genomes. PLRRP samples caused DNA damage to both genomes, and this was not increased by sunlight exposure, suggesting the DNA damage was unlikely the result of PAH phototoxicity. We report for the first time that PLRRP-associated pollutants cause both nuclear and mitochondrial DNA damage, and that fluoranthene-mediated phototoxicity results in similar levels of damage to the nuclear and mitochondrial genomes. These effects may be especially significant in sensitive marine ecosystems.

Keywords: DNA damage; Japanese medaka; Long amplicon QPCR assay; Parking lot runoff retention ponds; Phototoxicity; Polycyclic aromatic hydrocarbons (PAHs).

Figure 1

Dose response curve of the hazard ratios from 0.125X, 0.25X, 0.5X, and 1X dilution series of PLRRP water (A) before hatching and (B) after hatching. Error bars represent 95% confidence intervals.

Figure 2

Lesions/10kb in medaka DNA exposed to 5 J/m², 10 J/m², and 20 J/m² of direct UVC radiation.

Figure 3

Estimated lesions/10kb (SD) in medaka DNA exposed to control (ERM), fluoranthene (FLU), and parking lot runoff retention pond (PLRRP) solutions, ± natural solar radiation (light/dark). Error bars represent the standard error of the mean. *p ≤ 0.05 **p ≤ 0.001