Effects of estradiol and 11-ketotestosterone pre-treatment on artificial induction of maturation in silver female shortfinned eels (Anguilla australis)

PLoS One. 2020 Feb 24;15(2):e0229391. doi: 10.1371/journal.pone.0229391. eCollection 2020.

Abstract

Our previous work documented significant advancements in steroid-induced progression of oogenesis, demonstrating that co-treatment of female eels with 11-ketotestosterone (11KT) and estradiol-17β (E2) successfully induced uptake of vitellogenin by oocytes. Here we evaluate the effects of this steroid co-treatment on subsequent time to ovulation and egg quality in shortfinned eels artificially matured by hypophysation. Co-treatment with 11KT (1 mg) and E2 (0.2 or 2 mg) significantly reduced time to ovulation and therefore, the amount of pituitary homogenate required, without any detrimental effects on gonadosomatic index, oocyte diameter or the total weight of stripped eggs. E2 treatment resulted in promising increases in fertilization rates. These indicators suggest that co-treatment with 11KT and E2 holds promise for future artificial maturation practices in terms of minimising fish handling and stress, and of reducing the need for expensive pituitary preparations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anguilla* / physiology
  • Animals
  • Estradiol / pharmacology*
  • Female
  • Fertility / drug effects
  • Oocytes / cytology
  • Oocytes / drug effects
  • Oocytes / physiology
  • Oogenesis / drug effects*
  • Oogenesis / physiology
  • Ovary / cytology
  • Ovary / drug effects
  • Ovulation Induction* / methods
  • Ovulation Induction* / veterinary
  • Testosterone / analogs & derivatives*
  • Testosterone / pharmacology

Substances

  • Testosterone
  • Estradiol
  • 11-ketotestosterone

Grants and funding

This work was supported by a 2016 University of Otago Research grant and a 2018 PBRF Research Enhancement Grant (both PML). Publication fees were covered by a 2019 PBRF Research Enhancement Grant (ELD).