PUBLICATION

Recovery of reproductive function of female zebrafish from the toxic effects of microcystin-LR exposure

Authors
Kawan, A., Zhang, T., Liu, W., Mukhtar, H., Zhan, C., Zhang, X.
ID
ZDB-PUB-190719-22
Date
2019
Source
Aquatic toxicology (Amsterdam, Netherlands)   214: 105240 (Journal)
Registered Authors
Keywords
Endocrine disruptor, Microcystin-LR, Reproductive toxicity, Reversibility, Zebrafish
MeSH Terms
  • Animals
  • Endocrine Disruptors/toxicity
  • Environmental Exposure*
  • Female
  • Hormones/blood
  • Hypothalamus/drug effects
  • Hypothalamus/metabolism
  • Microcystins/toxicity*
  • Ovary/cytology
  • Ovary/drug effects
  • Ovary/physiology
  • Pituitary Gland/drug effects
  • Pituitary Gland/metabolism
  • Reproduction/drug effects*
  • Transcription, Genetic/drug effects
  • Water Pollutants, Chemical/toxicity
  • Zebrafish/blood
  • Zebrafish/genetics
  • Zebrafish/physiology*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
PubMed
31319295 Full text @ Aquat. Toxicol.
Abstract
Fish has a strong resistance to microcystins (MCs), cyclic heptapeptide cyanotoxins, known as endocrine disrupting chemicals (EDCs) which are released during cyanobacterial blooms and many laboratory and field studies have found the hepatic recovery of fish from the MCs exposure. The aim of the present study was to investigate the recovery mechanisms of reproductive function of adult zebrafish (Danio rerio) from microcystin-LR (MC-LR) exposure. Therefore, adult female zebrafish were exposed to 0, 1 or 50 μg/L of MC-LR for 21days and transferred to MC free water for another 21 days to investigate the recovery. After MC-LR exposure, marked histological lesions in the gonads, decreased the percentage of mature oocytes, decreased number of spawned eggs, decreased fertilization and hatching rates were observed. MC-LR exposure increased the concentration of 17β-estradiol (E2), testosterone (T) and vitellogenin (VTG) in female zebrafish. Some gene transcriptions of the hypothalamic-pituitary-gonad (HPG) axis significantly changed. The protein levels of 17βhsd and cyp19a remarkably increased in the MC-LR exposure groups. However, our laboratory observation also indicates that zebrafish transferred from microcystin exposure to toxin-free water and reared for 21 days exhibited a nearly complete recovery of reproductive functions, including histological structure, increased the percentage of matured oocytes and spawned eggs, stable hormone levels, well-balanced transcriptional and translational levels. These results indicate that after MC-LR exposure, the reproductive impairments in zebrafish are also reversible likewise hepatic recovery seen by different studies in fish. Future studies should be conducted to explore a better understanding of the recovery mechanisms of fish from microcystins exposure.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping