title: Embryonic exposure to butachlor in zebrafish (Danio rerio): endocrine disruption, developmental toxicity and immunotoxicity.
abstract: Butachlor is a chloroacetanilide herbicide widely employed in weeding important crops. Recently, the study of the possible toxic effects of butachlor in non-target organisms has increased substantially. However, the endocrine disruption, developmental toxicity and immunotoxicity effects of butachlor in fish have not been fully investigated in previous studies. In the present study, zebrafish embryos were exposed to a range of butachlor concentrations from 4 to 20 μM to evaluate the embryonic toxicity of butachlor until 84 hours postfertilization (hpf). The results demonstrated that butachlor was highly toxic to zebrafish embryos, hindering the hatching process, resulting in a series of malformations and followed by mortality. The malformations observed included pericardial edema (PE) and yolk sac edema (YSE), which showed concentration-dependent responses. The analysis of endocrine gene transcription indicated that butachlor significantly induced the expression of the estrogen-responsive gene Vtg1 but had no effect on the expression of the ERα gene. The innate immune system appeared to be another possible target of butachlor. At 72 hpf, butachlor significantly up-regulated the innate immune system-related genes, including IL-1β, CC-chem, CXCL-C1c and IL-8. These data suggest that butachlor causes developmental toxicity, endocrine disruption and immune toxicity in the zebrafish embryo. Bidirectional interactions between the endocrine system and the immune system might be present, and further studies are needed to determine these possible pathways.
authors.affiliation: Research Center of Environmental Science, College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, PR China.
authors.forename: Wenqing
authors.initials: W
authors.lastname: Tu
authors.forename: Lili
authors.initials: L
authors.lastname: Niu
authors.forename: Weiping
authors.initials: W
authors.lastname: Liu
authors.forename: Chao
authors.initials: C
authors.lastname: Xu
mesh_terms: D000083:Acetanilides / Q000633:toxicity*; D000818:Animals; D019743:Chemokines, CXC / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000187:drug effects*; D052244:Endocrine Disruptors / Q000633:toxicity*; D004703:Endocrine System / Q000187:drug effects*; D047628:Estrogen Receptor alpha / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D007107:Immune System / Q000187:drug effects*; D016209:Interleukin-8 / Q000378:metabolism; D010496:Pericardium / Q000187:drug effects; D014819:Vitellogenins / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015017:Yolk Sac / Q000187:drug effects; D015027:Zebrafish / Q000196:embryology* / Q000378:metabolism
chemical_list: D000083:Acetanilides; D019743:Chemokines, CXC; D052244:Endocrine Disruptors; D047628:Estrogen Receptor alpha; D016209:Interleukin-8; D014819:Vitellogenins; D014874:Water Pollutants, Chemical; C054409:butachlor