Estrogen receptor: A potential linker of estrogenic and dopaminergic pathways in zebrafish larvae following deltamethrin exposure

Deltamethrin (DM), a type II pyrethroid insecticide, is widely used to control agricultural pests. However, its excessive use exerts a detrimental effect on the ecological environment and human health, indicating the need to study its potential risks in detail. In the present study, zebrafish embryos were exposed to varying concentrations of DM (0.1, 1, 10, and 25 pg/L) for 96 h to assess the alterations in the transcript levels of proteins of the estrogenic and dopaminergic pathways. In addition, its effect on zebrafish locomotor activity was studied. The mRNA expression of cyp19a1b, er alpha, er beta 2, fshr, gnrh2, gnrhr3, vtg3, dat, and dr1 significantly changed after exposing the embryos to DM. Deltamethrin at 10 and 25 pg/L significantly reduced the average swimming speed of zebrafish larvae. In addition, embryos injected with zebrafish estrogen receptor a (era) and S (erS) morpholinos and co-exposed to 25 pg/L DM for 96 h showed reduced expression of vtg3 mRNA compared to embryos exposed to 25 pg/L DM only. The locomotor activity of era and erS knockdown zebrafish following DM exposure was increased significantly when compared with that of larvae exposed to 25 pg/L DM only. Our results demonstrated that DM altered the locomotor activity of zebrafish larvae and the transcript levels of the components of estrogenic and dopaminergic pathways; era and erS knockdown weakened these effects. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study found that Deltamethrin significantly impacts the locomotor activity of zebrafish embryos and the transcript levels of proteins in estrogenic and dopaminergic pathways. Knockdown of estrogen receptors a and S weakened these effects.