PUBLICATION

Microcystin-LR impairs zebrafish reproduction by affecting oogenesis and endocrine system

Authors
Zhao, Y., Xie, L., Yan, Y.
ID
ZDB-PUB-140712-1
Date
2015
Source
Chemosphere   120C: 115-122 (Journal)
Registered Authors
Keywords
Hypothalamic–pituitary–gonad axis, Microcystin-LR, Oocyte growth, Reproductive toxicity, Trans-generational effects
MeSH Terms
  • Animals
  • Endocrine System/drug effects*
  • Female
  • Gonadal Steroid Hormones/genetics
  • Gonadal Steroid Hormones/metabolism
  • Gonadotropin-Releasing Hormone/metabolism
  • Microcystins/toxicity*
  • Oogenesis/drug effects*
  • Pyrrolidonecarboxylic Acid/analogs & derivatives
  • Pyrrolidonecarboxylic Acid/metabolism
  • Reproduction/drug effects*
  • Vitellogenins/metabolism
  • Water Pollutants, Chemical/toxicity*
  • Zebrafish/growth & development*
  • Zebrafish/metabolism
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
PubMed
25014902 Full text @ Chemosphere
Abstract
Previous studies have shown that microcystins (MCs) are able to exert negative effects on the reproductive system of fish. However, few data are actually available on the effects of MC-LR on the reproductive system of female fish. In the present study, female zebrafish were exposed to 2, 10, and 50μgL(-1) of MC-LR for 21 d, and its effects on oogenesis, sex hormones, transcription of genes on the hypothalamic-pituitary-gonad (HPG) axis, and reproduction were investigated for the first time. It was observed that egg production significantly declined at ⩾10μgL(-1) MC-LR. MC-LR exposure to zebrafish increased the concentrations of 17β-estradiol (E2) and vitellogenin (VTG) at 10μgL(-1) level, whereas concentrations of E2, VTG and testosterone declined at 50μgL(-1) MC-LR. The transcriptions of steroidogenic pathway gene (cyp19a, cyp19b, 17βhsd, cyp17 and hmgra) changed as well after the exposure and corresponded well with the alterations of hormone levels. A number of intra- and extra-ovarian factors, such as gnrh3, gnrhr1, fshβ, fshr, lhr, bmp15, mrpβ, ptgs2 and vtg1 which regulate oogenesis, were significantly changed with a different dose-related effect. Moreover, MC-LR exposure to female zebrafish resulted in decreased fertilization and hatching rates, and may suggest the possibility of trans-generational effects of MC-LR exposure. The results demonstrate that MC-LR could modulate endocrine function and oogenesis, eventually leading to disruption of reproductive performance in female zebrafish. These data suggest there is a risk for aquatic population living in MC polluted areas.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping