Cylindrospermopsin induces oocyte maturation and disrupts gene expression in zebrafish ovarian follicles

Environ Toxicol Pharmacol. 2022 Aug:94:103915. doi: 10.1016/j.etap.2022.103915. Epub 2022 Jun 21.

Abstract

There is evidence that cylindrospermopsin (CYN) exerts reproductive toxicity in mice. However, little information is available concerning the toxicity of CYN in nonmammalian vertebrates. Here, we investigated the direct action of CYN on female reproduction by studying germinal vesicle breakdown, transcript abundance, caspase-3 activity, and testosterone production using cultured follicle-enclosed zebrafish oocytes as a model system. Treatment of follicles with 1,000 μg/L CYN significantly increased GVBD, Caspase-3 activity, and hCG-induced testosterone secretion. Exposure to CYN also reduced the abundance of 3βhsd as well as hCG-induced fshr and era transcripts and increased cyp19a1 mRNA levels. In summary, this study provides a framework for a better understanding of the adverse action of CYN on female reproduction in zebrafish and other vertebrate species. The findings are also relevant to developing valid biomarkers for CYN by measuring zebrafish oocyte maturation and gene expression.

Keywords: Cyanotoxin; Endocrine disruptor; Reproductive toxicology; in vitro.

MeSH terms

  • Alkaloids
  • Animals
  • Caspase 3 / metabolism
  • Cyanobacteria Toxins
  • Female
  • Gene Expression
  • Mice
  • Oocytes
  • Ovarian Follicle* / metabolism
  • Testosterone / metabolism
  • Zebrafish* / genetics

Substances

  • Alkaloids
  • Cyanobacteria Toxins
  • cylindrospermopsin
  • Testosterone
  • Caspase 3