Differential expression of largemouth bass (Micropterus salmoides) estrogen receptor isotypes alpha, beta, and gamma by estradiol

Effects of steroid hormones on reproduction- and detoxification-related gene expression in adult male mosquitofish, Gambusia affinis

“…Our present and previous results suggested that ER subtype mRNAs showed different expression patterns between the liver and gonad (testis or ovary) in response to steroid hormones. Sabo-Attwood et al (2004) have also reported that, in largemouth bass, three different ER subtypes are regulated differentially among tissues, temporally and in response to E2. Although the reason for tissue-specific suppression of ER subtypes is unclear, the results do point to a targeted disruption of steroid signaling in the particular tissue of mosquitofish depending on sex.…”

“…The results presented herein showed that ERα plays a dominant role in the up-regulation of Vtg mRNA expression in the liver of male mosquitofish. It has been shown that ERα plays a dominant role in the up-regulation of Vtg mRNA expression in the liver of female mosquitofish (Huang et al, 2012) and other fish (Sabo-Attwood et al, 2004;Davis et al, 2007) by E2. The lack of significant changes found in ERβ mRNA expression levels in the liver of male mosquitofish in response to E2 is consistent with other studies in which E2 treatment had no effects on zebrafish (Menuet et al, 2004) and male goldfish (Pomatto et al, 2011), suggesting that ERβ is unlikely to be the primary mediator of E2 actions on the liver associated with the induction of Vtg mRNA expression.…”

Distinct expression and activity profiles of largemouth bass (Micropterus salmoides) estrogen receptors in response to estradiol and nonylphenol

“…Recently, three ER isotypes have been shown to exist in fish as reported by us and others (Hawkins et al 2000, Legler et al 2002, Sabo-Attwood et al 2004, Filby & Tyler 2005. The three ERs, originally termed ERa, ERb, and ERg, were recently renamed ERa, ERbb, and ERba respectively, to comply with official zebrafish (zf) nomenclature (Hawkins & Thomas 2004, Filby & Tyler 2005.…”

Regulation of reproduction- and biomarker-related gene expression by sex steroids in the livers and ovaries of adult female western mosquitofish (Gambusia affinis)

“…Many previous studies in teleosts showed that the expression of hepatic ERα mRNA is significantly induced by E2 treatment (Sabo-Attwood et al, 2004;Esterhuyse et al, 2010;Marlatt et al, 2010). In contrast to ERα, ERβ transcriptional regulation by estrogen seems to be more variable depending on the species and ERβ subtypes (Sabo-Attwood et al, 2004;Pinto et al, 2006;Esterhuyse et al, 2010). ERα auto-regulation in the livers is a common feature of teleosts that has been attributed to be involved in Vtg gene transcription in the livers of mature females in response to E2 (Pinto et al, 2006).…”

“…ERs were localized in both sexes in numerous tissues and are able to modify transcriptional rates of estrogen response genes through binding as dimers to estrogen response elements (EREs) in the promoter regions of those target genes (Janošek et al, 2006;Pinto et al, 2006;Kim et al, 2010). Until now, two distinct types of ERs (called ERα and ERβ) have been isolated in several fish species including largemouth bass (Sabo-Attwood et al, 2004), mosquitofish (Katsu et al, 2007), tilapia (Esterhuyse et al, 2010), and in cinnamon clownfish (Kim et al, 2010). Role of the androgen receptor (AR) in male organism is very similar to that of estrogen receptor in females (Janošek et al, 2006;Smolinsky et al, 2010).…”