PUBLICATION

Pyriproxyfen induced impairment of reproductive endocrine homeostasis and gonadal histopathology in zebrafish (Danio rerio) by altered expression of hypothalamus-pituitary-gonadal (HPG) axis genes

Authors
Maharajan, K., Muthulakshmi, S., Karthik, C., Nataraj, B., Nambirajan, K., Hemalatha, D., Jiji, S., Kadirvelu, K., Liu, K.C., Ramesh, M.
ID
ZDB-PUB-200603-6
Date
2020
Source
The Science of the total environment   735: 139496 (Journal)
Registered Authors
Keywords
Endocrine disruption, Estradiol, Ovary, Testes, Testosterone, Vitellogenin
MeSH Terms
  • Animals
  • Endocrine Disruptors*
  • Endocrine System/drug effects
  • Female
  • Gonads/drug effects
  • Homeostasis
  • Hypothalamus
  • Male
  • Pyridines
  • Reproduction
  • Vitellogenins
  • Water Pollutants, Chemical/pharmacology*
  • Zebrafish
PubMed
32480152 Full text @ Sci. Total Environ.
Abstract
Pyriproxyfen (PPF), a broad-spectrum insecticide known to cause reproductive and endocrine disruption in invertebrates, while the data is scarce in aquatic vertebrates. The goal of this study is to investigate the impact of PPF on reproductive endocrine system of male and female zebrafish along hypothalamus-pituitary-gonadal (HPG) axis. In brain, PPF caused significant alteration in the transcripts of erα, lhβ, and cyp19b genes in male and fshβ, lhβ, and cyp19b genes in female zebrafish. The downstream genes of steroidogenic pathway like, star, 3βhsd, 17βhsd, and cyp19a expression were significantly altered in gonad of both sexes. Subsequent changes in circulatory steroid hormone levels lead to imbalance in hormone homeostasis as revealed from estradiol/testosterone (E2/T) ratio. Further, the vitellogenin transcript level was enhanced in hepatic tissues and their blood plasma content was increased in male (16.21%) and declined in female (21.69%). PPF also induced histopathological changes in gonads such as, reduction of mature spermatocytes in male and vitellogenic oocytes in female zebrafish. The altered E2/T ratio and gonadal histopathology were supported by the altered transcript levels of HPG axis genes. Overall, these findings provide new insights of PPF in zebrafish reproductive system and highlights for further investigations on its potential risks in aquatic environment.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping