Zebrafish as a possible bioindicator of organic pollutants in drinking waters with effects on reproduction: are effects cumulative or reversible?

Abstract

Organic pollutants are present in drinking waters due to inefficient detection and removal treatments. For this reason, zebrafish is proposed as a complementary indicator in conventional potabilization treatments. Based on the most sensitive parameters detected in our previous work, in this study we attempted to examine the possible cumulative effect between generations of environmental pollutants likely present in drinking waters, when specimens were cultured in the same water and/or the possible reversibility of these effects when cultured in control water. To this end, embryos with the chorion intact were cultured in three drinking waters from different sources and in one control water for up to 5 months in 20 l glass tanks. Four replicates were performed in all water groups. Results in water group C (tap water from a city also located in a region with intensive agricultural activity, but from the hydrological basin of the river Xúquer) revealed a non-reversible effect on fertility rate. Also in water C there was an alteration of sex ratio towards females, although in this case the alteration was reversible. A transgenerational alteration in the germ-line via an epigenetic mechanism from the previous generation is proposed as the most plausible explanation of this effect.

Chronic Toxic Effects of Flutolanil on the Liver of Zebrafish (Danio rerio)

“…Zebrafish ( Danio rerio ) have been used for investigating the chronic toxicity of exogenous pollutants because of their advantages including low cost, small size, embryonic transparent, short reproductive cycle, and high genetic similarity to human. , …”

“…11−13 Zebrafish (Danio rerio) have been used for investigating the chronic toxicity of exogenous pollutants because of their advantages including low cost, small size, embryonic transparent, short reproductive cycle, and high genetic similarity to human. 14,15 In this study, zebrafish are used to evaluate the toxic effects of flutolanil at concentrations relevant to environmental conditions. We determined the activities of CAT and SOD, the levels of malondialdehyde (MDA), 8-hydroxy-2, deoxyguanosine (8-OHdG) related to oxidative stress, and the transcriptional alterations of genes involved in apoptotic and immune system pathways.…”