In vitro conversion of androgen to estrogen in amphioxus gonadal tissues

Callard, Gloria V.; Pudney, Jeffrey; Kendall, Susan L.; Reinboth, Rudolf

doi:10.1016/0016-6480(84)90060-1

Cited by 37 publications

(14 citation statements)

References 12 publications

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“…Several aspects of steroid metabolism were described in amphioxus [60] and the homologues of many enzymes necessary for estradiol synthesis in mammals were cloned from amphioxus ovaries [15,61]. Of particular interest is the report of an aromatase gene (CYP19) in amphioxus, which suggests that the crucial step in estradiol synthesis is indeed possible in amphioxus.…”

Section: Discussionmentioning

confidence: 99%

An amphioxus orthologue of the estrogen receptor that does not bind estradiol: Insights into estrogen receptor evolution

et al. 2008

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BackgroundThe origin of nuclear receptors (NRs) and the question whether the ancestral NR was a liganded or an unliganded transcription factor has been recently debated. To obtain insight into the evolution of the ligand binding ability of estrogen receptors (ER), we comparatively characterized the ER from the protochordate amphioxus (Branchiostoma floridae), and the ER from lamprey (Petromyzon marinus), a basal vertebrate.ResultsExtensive phylogenetic studies as well as signature analysis allowed us to confirm that the amphioxus ER (amphiER) and the lamprey ER (lampER) belong to the ER group. LampER behaves as a "classical" vertebrate ER, as it binds to specific DNA Estrogen Responsive Elements (EREs), and is activated by estradiol (E2), the classical ER natural ligand. In contrast, we found that although amphiER binds EREs, it is unable to bind E2 and to activate transcription in response to E2. Among the 7 natural and synthetic ER ligands tested as well as a large repertoire of 14 cholesterol derivatives, only Bisphenol A (an endocrine disruptor with estrogenic activity) bound to amphiER, suggesting that a ligand binding pocket exists within the receptor. Parsimony analysis considering all available ER sequences suggest that the ancestral ER was not able to bind E2 and that this ability evolved specifically in the vertebrate lineage. This result does not support a previous analysis based on ancestral sequence reconstruction that proposed the ancestral steroid receptor to bind estradiol. We show that biased taxonomic sampling can alter the calculation of ancestral sequence and that the previous result might stem from a high proportion of vertebrate ERs in the dataset used to compute the ancestral sequence.ConclusionTaken together, our results highlight the importance of comparative experimental approaches vs ancestral reconstructions for the evolutionary study of endocrine systems: comparative analysis of extant ERs suggests that the ancestral ER did not bind estradiol and that it gained the ability to be regulated by estradiol specifically in the vertebrate lineage, before lamprey split.

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Section: Discussionmentioning

confidence: 99%

An amphioxus orthologue of the estrogen receptor that does not bind estradiol: Insights into estrogen receptor evolution

et al. 2008

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“…With ongoing identification of aromatase activity and in vivo estrogen production in invertebrates (Callard et al 1984;Matsumoto et al 1997;Le Curieux-Belfond et al 2001, Oberdorster andMcClellan-Green 2002;Santos et al 2002;Twan et al 2003), it is possible that this protein, and its function in the production of estrogens, has been conserved outside of the vertebrates.…”

Section: Diverge Analysismentioning

confidence: 99%

Cytochrome P450 1A1 and aromatase (CYP19) in cetaceans : enzyme expression and relationship to contaminant exposure

Wilson¹

2003

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“…The amphioxus genome encodes two nuclear receptors that are similar to the sex steroid receptors in vertebrates (Schubert et al 2008) and a set of enzymes that act in the synthesis of estradiol, testosterone, and progesterone. Although these steroids have been identified in the amphioxus gonad (Callard et al 1984; Mizuta and Kubokawa 2007), only estradiol has been shown to bind one of the steroidal receptors (Paris et al 2008; Katsu et al 2010). Nonetheless, amphioxus has considerable potential for reproductive cycle feedback at the level of the nervous system, gonads, and other tissues that may be targeted by the sex steroids.…”

Section: Introductionmentioning

confidence: 99%

At the Transition from Invertebrates to Vertebrates, a Novel GnRH-Like Peptide Emerges in Amphioxus

Roch

Tello

Sherwood

2013

Molecular Biology and Evolution

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Gonadotropin-releasing hormone (GnRH) is a critical reproductive regulator in vertebrates. Homologous peptides are also found in invertebrates, with a variety of characterized functions. In the amphioxus, an invertebrate that provides the best model for the transition to vertebrates, four GnRH receptors (GnRHRs) were previously described, but their native ligands were not identified. Using a more sensitive search methodology with hidden Markov models, we identified the first GnRH-like peptide confirmed in the amphioxus Branchiostoma floridae. This peptide specifically activated one of the four GnRHRs. Although the primary structure of this peptide was divergent from any previously isolated GnRH peptide, the minimal conserved residues found in all other GnRH superfamily members were retained. The peptide was immunolocalized in proximity of the central canal of the anterior nerve cord, a region where other neuropeptides and receptors have been found. Additionally, the amphioxus GnRH-like gene was positioned in a locus surrounded by syntenic homologs of the human GnRH paralogon. The amphioxus GnRH-like peptide, with its distinct primary structure, activated a receptor with equal potency to multiple ligands that span the GnRH superfamily.

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In vitro conversion of androgen to estrogen in amphioxus gonadal tissues

Cited by 37 publications

References 12 publications

An amphioxus orthologue of the estrogen receptor that does not bind estradiol: Insights into estrogen receptor evolution

An amphioxus orthologue of the estrogen receptor that does not bind estradiol: Insights into estrogen receptor evolution

Cytochrome P450 1A1 and aromatase (CYP19) in cetaceans : enzyme expression and relationship to contaminant exposure

At the Transition from Invertebrates to Vertebrates, a Novel GnRH-Like Peptide Emerges in Amphioxus

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