The interaction between cortisol and aromatase may be a critical factor in sex determination or sex changes in teleost species. High cortisol concentrations inhibit transcription of the aromatase gene, resulting in masculinization. Anemonefish (Amphiprion spp.) are socially controlled, protandrous sex-changing fish, with a monogamous mating system. Females are the largest and most dominant members of social groups, second-ranking individuals become males, and other individuals remain nonreproductive. Individuals that change from male to female display high plasma cortisol concentrations, contrary to a previously established mechanism of masculinization. We investigated the effects of exogenous steroids on gene expression in the brain and gonads and on the occurrence of dominant behavior in the sexually immature ambisexual false clown anemonefish Amphiprion ocellaris. Transcription of the cyp19a1a aromatase gene increased in the gonads of estradiol pellet-fed fish but decreased in cortisol pellet-fed fish. Dominant behavior intensity significantly increased in estradiol pellet-fed fish, but decreased in cortisol pellet-fed fish. Methyltestosterone had no apparent effect on gene transcription or behavior. These results suggest that the masculinization mechanism induced by cortisol is common among teleost species, including protandrous sex-changing fish, and that behavioral changes induced by steroid supplements reflect social status in A. ocellaris.

中文翻译：

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假小丑海葵Amphiprion ocellaris芳香化酶基因的甾体调节及显性行为

皮质醇和芳香酶之间的相互作用可能是硬骨鱼物种性别决定或性别变化的关键因素。高浓度的皮质醇会抑制芳香酶基因的转录，导致男性化。Anemonefish (Amphiprion spp.) 是社会控制的、突出的变性鱼，具有一夫一妻制的交配系统。女性是社会群体中最大和最主要的成员，排名第二的个体成为男性，而其他个体保持非生育能力。从男性变为女性的个体显示出高血浆皮质醇浓度，这与先前建立的男性化机制相反。我们调查了外源性类固醇对大脑和性腺中基因表达的影响，以及对性不成熟双性假小丑海葵鱼 Amphiprion ocellaris 中显性行为发生的影响。cyp19a1a 芳香酶基因的转录在雌二醇颗粒喂养的鱼的性腺中增加，但在皮质醇颗粒喂养的鱼中减少。雌二醇颗粒喂养的鱼的优势行为强度显着增加，但皮质醇颗粒喂养的鱼的优势行为强度显着增加。甲基睾酮对基因转录或行为没有明显影响。这些结果表明，皮质醇诱导的男性化机制在硬骨鱼类中很常见，包括雄性变性鱼，类固醇补充剂诱导的行为变化反映了 A. ocellaris 的社会地位。cyp19a1a 芳香酶基因的转录在雌二醇颗粒喂养的鱼的性腺中增加，但在皮质醇颗粒喂养的鱼中减少。雌二醇颗粒喂养的鱼的优势行为强度显着增加，但皮质醇颗粒喂养的鱼的优势行为强度显着增加。甲基睾酮对基因转录或行为没有明显影响。这些结果表明，皮质醇诱导的男性化机制在硬骨鱼类中很常见，包括雄性变性鱼，类固醇补充剂诱导的行为变化反映了 A. ocellaris 的社会地位。cyp19a1a 芳香酶基因的转录在雌二醇颗粒喂养的鱼的性腺中增加，但在皮质醇颗粒喂养的鱼中减少。雌二醇颗粒喂养的鱼的优势行为强度显着增加，但皮质醇颗粒喂养的鱼的优势行为强度显着增加。甲基睾酮对基因转录或行为没有明显影响。这些结果表明，皮质醇诱导的男性化机制在硬骨鱼类中很常见，包括雄性变性鱼，类固醇补充剂诱导的行为变化反映了 A. ocellaris 的社会地位。甲基睾酮对基因转录或行为没有明显影响。这些结果表明，皮质醇诱导的男性化机制在硬骨鱼类中很常见，包括雄性变性鱼，类固醇补充剂诱导的行为变化反映了 A. ocellaris 的社会地位。甲基睾酮对基因转录或行为没有明显影响。这些结果表明，皮质醇诱导的男性化机制在硬骨鱼类中很常见，包括雄性变性鱼，类固醇补充剂诱导的行为变化反映了 A. ocellaris 的社会地位。