An in vitro ovarian explant culture system to examine sex change in a hermaphroditic fish

PeerJ

article

Alexander Goikoetxea¹  Erin L. Damsteegt²  Erica V. Todd³  Andrew McNaughton¹  Neil J. Gemmell¹  P. Mark Lokman² 

[1] Department of Anatomy, University of Otago;Department of Zoology, University of Otago;School of Life and Environmental Science, Deakin University

关键词: Organ culture;    Sex change;    Previtellogenic oocyte;    Cortisol;    Spotty wrasse;   

DOI  :  10.7717/peerj.10323

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Many teleost fishes undergo natural sex change, and elucidating the physiological and molecular controls of this process offers unique opportunities not only to develop methods of controlling sex in aquaculture settings, but to better understand vertebrate sexual development more broadly. Induction of sex change in some sequentially hermaphroditic or gonochoristic fish can be achieved in vivo through social manipulation, inhibition of aromatase activity, or steroid treatment. However, the induction of sex change in vitro has been largely unexplored. In this study, we established an in vitro culture system for ovarian explants in serum-free medium for a model sequential hermaphrodite, the New Zealand spotty wrasse (Notolabrus celidotus). This culture technique enabled evaluating the effect of various treatments with 17β-estradiol (E2), 11-ketotestosterone (11KT) or cortisol (CORT) on spotty wrasse ovarian architecture for 21 days. A quantitative approach to measuring the degree of ovarian atresia within histological images was also developed, using pixel-based machine learning software. Ovarian atresia likely due to culture was observed across all treatments including no-hormone controls, but was minimised with treatment of at least 10 ng/mL E2. Neither 11KT nor CORT administration induced proliferation of spermatogonia (i.e., sex change) in the cultured ovaries indicating culture beyond 21 days may be needed to induce sex change in vitro. The in vitro gonadal culture and analysis systems established here enable future studies investigating the paracrine role of sex steroids, glucocorticoids and a variety of other factors during gonadal sex change in fish.

【 授权许可】

CC BY