PUBLICATION

Why Western Mosquitofish (Gambusia affinis) Is Tolerant to Se Contamination: Complex Mechanistic Explanations

Authors
Wei, X., Li, X., Zhou, W., Yan, B., Chen, T., Wu, F., Luo, Y., Mu, J., Zhang, Y.T., Chen, H., Xie, L.
ID
ZDB-PUB-250426-9
Date
2025
Source
Environmental science & technology : (Journal)
Registered Authors
Keywords
Danio rerio, Gambusia affinis, Se contamination, Se efflux, reproductive biology, tolerance to Se
MeSH Terms
  • Animals
  • Cyprinodontiformes*
  • Water Pollutants, Chemical/toxicity
  • Zebrafish
  • Selenomethionine/toxicity
  • Selenium*
PubMed
40279166 Full text @ Env. Sci. Tech.
Abstract
The western mosquitofish (Gambusia affinis (G. affinis)) is often the only fish that survives in various selenium-contaminated aquatic environments. However, mechanisms of its survival in such environments remain seldom explored. In this study, the acute toxicity of selenomethionine (Se-Met) in a variety of species (four oviparous and four ovoviviparous species) was evaluated, followed by the chronic effects of Se-Met on G. affinis and on zebrafish (Danio rerio (D. rerio)), focusing on Se accumulation in the gonads and offspring, reproductive biology, and offspring development. Our results showed that the LC50-96h of Se-Met was the largest in G. affinis among the eight fish, confirming its elevated resistance to Se. Meanwhile, the transcripts of genes related to selenoproteins and sulfoproteins showed opposite responses between G. affinis and D. rerio to Se-Met exposure, along with the altered levels of total selenoproteins in oviparous but not in ovoviviparous fish. The chronic exposures showed that Se levels in the gonads, effects on gonadal development and embryonic and early larval development, and Se efflux in the embryos and larvae were apparently different between G. affinis and D. rerio. Finally, differentially expressed genes (particularly antioxidant and inflammation) were mostly stimulated in G. affinis but inhibited in D. rerio. This study has demonstrated that the Se efflux capacity of the offspring and genes related to Se metabolism and antioxidant physiology can help partially explain the survival of G. affinis in Se-contaminated ecosystems.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping