Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Ecotoxicol Environ Saf
2021 Sep 01;220:112417. doi: 10.1016/j.ecoenv.2021.112417.
Show Gene links
Show Anatomy links
Xenopus laevis tadpoles exposed to metamifop: Changes in growth, behavioral endpoints, neurotransmitters, antioxidant system and thyroid development.
Liu R
,
Qin Y
,
Diao J
,
Zhang H
.
???displayArticle.abstract???
Pesticides are a major cause of the reduction in the global amphibian population. In this study, the acute toxicity and chronic effects of metamifop on Xenopus laevis (X. laevis) tadpoles were investigated. The 96 h-LC50 value of metamifop on X. laevis tadpoles was 0.634 mg/L, which indicated that metamifop was highly toxic to tadpoles. In the chronic toxicity study, tadpoles were exposed to 0.063 mg/L of metamifop. After 14, 21 and 35 d of exposure, metamifop significantly inhibited the body weight and neurotransmitter synthesis of tadpoles, caused abnormal behavior and interfered with fat metabolism. According to the results of antioxidant enzymes and malondialdehyde (MDA), tadpoles exposed to 0.063 mg/L metamifop suffered severe lipid oxidative damage. Compared with the control group, the thyroid hormone (TH) levels and related gene expression in tadpoles in the treatment group were affected, reflecting the endocrine interference effect of metamifop. The data of this study can enrich our knowledge of the effects of aryloxyphenoxy propionate pesticides on amphibians and highlight the role of metamifop and other pesticides play in global decline of amphibians.
Fig. 1. Average body weight, TG and T-CHO contents in X. laevis tadpoles exposed to metamifop for 14,21 and 35 days (N = 3). abc: different letters represent statistically significant differences (SNK) at P < 0.05, whereas the same letter indicates no significant difference. * Denotes significant difference between control and treatments at P < 0.05, ** denotes significant difference between control and treatments at P < 0.01. Error bars indicate the standard deviation.
Fig. 2. Gly and GABA concentrations in X. laevis tadpoles exposed to metamifop for 14,21 and 35 days (N = 3). abc: different letters represent statistically significant differences (SNK) at P < 0.05, whereas the same letter indicates no significant difference. * Denotes significant difference between control and treatments at P < 0.05, ** denotes significant difference between control and treatments at P < 0.01. Error bars indicate the standard deviation.
Fig. 3. T3 and T4 levels in X. laevis tadpoles exposed to metamifop for 14,21 and 35 days (N = 3). abc: different letters represent statistically significant differences (SNK) at P < 0.05, whereas the same letter indicates no significant difference. * Denotes significant difference between control and treatments at P < 0.05, ** denotes significant difference between control and treatments at P < 0.01. Error bars indicate the standard deviation.
Fig. 4. The mRNA relative expression of thyroid stimulating hormone α (tshα), thyroid stimulating hormone β (tshβ), thyroid hormone receptors α (tr α) and thyroid hormone receptors β (tr β) in X. laevis tadpoles exposed to metamifop for 14, 21 and 35 days. abc: different letters represent statistically significant differences (SNK) at P < 0.05, whereas the same letter indicates no significant difference. * Denotes significant difference between control and treatments at P < 0.05, ** denotes significant difference between control and treatments at P < 0.01. Error bars indicate the standard deviation.
Fig. 5. The mRNA relative expression of type II deiodinase (dio2) and type III deiodinase (dio3) in X. laevis tadpoles exposed to metamifop for 14, 21 and 35 days. abc: different letters represent statistically significant differences (SNK) at P < 0.05, whereas the same letter indicates no significant difference. * Denotes significant difference between control and treatments at P < 0.05, ** denotes significant difference between control and treatments at P < 0.01. Error bars indicate the standard deviation.
Figure 1. Structure of metamifop.
Figure S2. T-SOD and CAT activities and MDA content in X. laevis tadpoles exposed to metamifop for 14, 21 and 35 days. abc: different letters represent statistically significant differences (SNK) at P<0.05, whereas the same letter indicates no significant difference. * Denotes significant difference between the control and treatments at P<0.05, ** Denotes significant difference between the control and treatments at P<0.01. Error bars indicate standard deviation.
