J 2020

Environmentally relevant mixture of S-metolachlor and its two metabolites affects thyroid metabolism in zebrafish embryos

ROZMÁNKOVÁ, Eliška, Marek PÍPAL, Lucie BLÁHOVÁ, Naveen NJATTUVETTY CHANDRAN, Benedicte MORIN et. al.

Basic information

Original name

Environmentally relevant mixture of S-metolachlor and its two metabolites affects thyroid metabolism in zebrafish embryos

Authors

ROZMÁNKOVÁ, Eliška (203 Czech Republic, belonging to the institution), Marek PÍPAL (203 Czech Republic, belonging to the institution), Lucie BLÁHOVÁ (203 Czech Republic, belonging to the institution), Naveen NJATTUVETTY CHANDRAN (356 India, belonging to the institution), Benedicte MORIN (250 France), Patrice GONZALEZ (250 France) and Luděk BLÁHA (203 Czech Republic, guarantor, belonging to the institution)

Edition

Aquatic toxicology, Amsterdam, Elsevier Science BV, 2020, 0166-445X

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10617 Marine biology, freshwater biology, limnology

Country of publisher

Netherlands

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 4.964

RIV identification code

RIV/00216224:14310/20:00116065

Organization unit

Faculty of Science

UT WoS

000526050100010

Keywords in English

Zebrafish embryo; Embryotoxicity; Pesticide mixture; Environmental concentration; Sublethal effects; Metabolite

Tags

Tags

International impact, Reviewed
Změněno: 5/3/2021 16:48, Mgr. Marie Šípková, DiS.

Abstract

V originále

Herbicides and their metabolites are often detected in water bodies where they may cause adverse effects to non-target organisms. Their effects at environmentally relevant concentrations are often unclear, especially concerning mixtures of pesticides. This study thus investigated the impacts of one of the most used herbicides: S-metolachlor and its two metabolites, metolachlor oxanilic acid (MOA) and metolachlor ethanesulfonic acid (MESA) on the development of zebrafish embryos (Danio rerio). Embryos were exposed to the individual substances and their environmentally relevant mixture until 120 hpf (hours post-fertilization). The focus was set on sublethal endpoints such as malformations, hatching success, length of fish larvae, spontaneous movements, heart rate and locomotion. Moreover, expression levels of eight genes linked to the thyroid system disruption, oxidative stress defense, mitochondrial metabolism, regulation of cell cycle and retinoic acid (RA) signaling pathway were analyzed. Exposure to S-metolachlor (1 mu g/L) and the pesticide mixture (1 mu g/L of each substance) significantly reduced spontaneous tail movements of 21 hpf embryos. Few rare developmental malformations were observed, but only in larvae exposed to more than 100 mu g/L of individual substances (craniofacial deformation, non-inflated gas bladder, yolk sac malabsorption) and to 30 mu g/L of each substance in the pesticide mixture (spine deformation). No effect on hatching success, length of larvae, heart rate or larvae locomotion were found. Strong responses were detected at the molecular level including induction of p53 gene regulating the cell cycle (the pesticide mixture - 1 mu g/L of each substance; MESA 30 mu g/L; and MOA 100 mu g/L), as induction of cyp26a1 gene encoding cytochrome P450 (pesticide mixture - 1 mu g/L of each substance). Genes implicated in the thyroid system regulation (dio2, thra, thrb) were all overexpressed by the environmentally relevant concentrations of the pesticide mixture (1 mu g/L of each substance) and MESA metabolite (1 mu g/L). Zebrafish thyroid system disruption was revealed by the overexpressed genes, as well as by some related developmental malformations (mainly gas bladder and yolk sac abnormalities), and reduced spontaneous tail movements. Thus, the thyroid system disruption represents a likely hypothesis behind the effects caused by the low environmental concentrations of S-metolachlor, its two metabolites and their mixture.

Links

EF17_043/0009632, research and development project
Name: CETOCOEN Excellence
LM2015051, research and development project
Name: Centrum pro výzkum toxických látek v prostředí (Acronym: RECETOX RI)
Investor: Ministry of Education, Youth and Sports of the CR