Zebrafish sex differentiation and gonad development after exposure to 17α-ethinylestradiol, fadrozole and their binary mixture: A stereological study

Disruption of apoptosis pathways involved in zebrafish gonad differentiation by 17α-ethinylestradiol and fadrozole exposures

“…These observations suggest that estrogen exposure delays the normal sexual differentiation of males in this species, rather than promoting a real and definitive sex reversal (Fenske et al, 2005;Hill and Janz, 2003;Maack and Segner, 2004). Oppositely, exposures to the aromatase inhibitor fadrozole (Fad) promote the appearance of zebrafish male-biased populations (Andersen et al, 2005;Fenske and Segner, 2004;Luzio et al, 2015bLuzio et al, , 2016aUchida et al, 2004). The effects of both androgenic and aromatase inhibitor compounds are described to be more persistent and irreversible than the ones induced by estrogenic compounds (Baumann et al, 2015;Fenske and Segner 2004;Larsen and Baatrup, 2010;Luzio et al, 2016a;Morthorst et al, 2010).…”

“…In fact, this transformation apparently results from the action of several signaling pathways, such as Tp53/fancl (Rodríguez-Marí et al, 2010), nuclear factor kappa B (NF-B) (Pradhan et al, 2012) and canonical Wnt (Sreenivasan et al, 2014). However, none of these studies have compared the two processes of gonad development (i.e., with or without the "juvenile ovary") separately in juvenile males during gonad transformation (Luzio et al, 2015b(Luzio et al, , 2016aWang et al, 2007).…”

“…In recent years, it has been also proposed, at least for zebrafish laboratory strains, that its sex determination has a polygenic basis (Anderson et al, 2012;Bradley et al, 2011;Liew et al, 2012;Luzio et al, 2015a;Wilson et al, 2014), highly sensitive to the influence of environmental factors (Abozaid et al, 2012;Luzio et al, 2015bLuzio et al, , 2016aÖrn et al, 2016;Shang et al, 2006).…”

“…The EDCs can disrupt the function of the endocrine system (Scholz and Mayer, 2008), with a wide range of studies reporting the induction of sex-biased populations after exposures to these compounds (Fenske and Segner, 2004;Fenske et al, 2005;Luzio et al, 2015b;Örn et al, 2016).…”

“…Among environmental factors, endocrine disrupting chemicals (EDCs) are known to influence zebrafish sex determination and differentiation (Baumann et al, 2014;Luzio et al, 2015bLuzio et al, , 2016bÖrn et al, 2016). The EDCs can disrupt the function of the endocrine system (Scholz and Mayer, 2008), with a wide range of studies reporting the induction of sex-biased populations after exposures to these compounds (Fenske and Segner, 2004;Fenske et al, 2005;Luzio et al, 2015b;Örn et al, 2016).…”