Study of locomotion response and development in zebrafish (Danio rerio) embryos and larvae exposed to enniatin A, enniatin B, and beauvericin.

Abstract

Mycotoxins are secondary metabolites produced by a variety of fungi that contaminate food and feed resources, and are capable of inducing a wide range of toxicity. Here, we studied the developmental and behavioral toxicity in zebrafish (Danio rerio) embryos and larvae exposed to three mycotoxins: beauvericin (BEA), Enniatin A (ENN A), and Ennitain B (ENN B). Zebrafish embryos were collected after fertilization, treated individually from 1 to 6 dpf with BEA at 8, 16, 32 and, 64μM and for both enniatins at 3.12, 6.25, 12.5 and, 25μM. Mixture of mycotoxins were assayed as follows: i) for BEA+ENN A and BEA+ENN B at [32+12.5] μM and [16+6.25] μM; ii) for ENN A+ENN B at [12.5+12.5] μM and [6.25+6.25] μM and, iii) for BEA+ENN A+ENN B at [32+12.5+12.5] μM and [16+6.25+6.25] μM. Response was collected after a white light-flash intermittent coming on for 5s during 2h with a imaging platform. Outcomes measured were: time to death, response to light, and circadian rhythm. This last outcome was measured in a plate where embryos had evolved in natural intervals of light and dark until day 7 or in a plate maintained in darkness. Images of all stages and evolution were collected. Results indicated that mycotoxins induced toxicity at the concentrations tested. All exposed zebrafish induced developmental defects, specifically hatching time and motion activity. After exposure, fish showed enhanced baseline activity but they lost their responsiveness to light.