Ramallo Martín R, Honji Renato M, Birba Agustina, Morandini Leonel, Varela María L, Genovese Griselda, Moreira Renata G, Somoza Gustavo M, Pandolfi Matías
Laboratorio de Neuroendocrinología y Comportamiento, DBBE, IBBEA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CABA, Argentina.
Departamento de Fisiologia do Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
Gen Comp Endocrinol. 2017 Oct 1;252:119-129. doi: 10.1016/j.ygcen.2017.08.009. Epub 2017 Aug 7.
For many species parental behavior is essential for the survival of the offspring. While the ultimate causes of teleost parental behavior have been widely studied, comparatively little is known about its proximate causes. The aim of this study was to analyze the yet unexplored, potential dual role of brain and gonadal aromatases, the enzymes responsible for the conversion of androgens to estrogens in the brains and gonads of teleosts, respectively, on the different stages of the maternal care period of the biparental cichlid Cichlasoma dimerus, locally known as chanchita. By immunohistochemistry we analyzed the neural distribution of brain aromatase and observed it exclusively within the forebrain, including areas involved in the regulation of parental behavior. We next analyzed the gene expression of brain aromatase in the brain, and gonadal aromatase in the ovary, of female chanchitas through the parental care period. To further characterize the physiological environment associated to maternal care, we also evaluated sex steroid levels (17β-estradiol, testosterone and 11-ketotestoterone) and ovarian follicle percentage. The onset of parental behavior specifically downregulated sex steroids synthesis and the rate of ovarian maturation, as denoted by a more than 10-fold decrease in steroid levels and delayed detection of mature follicles in females with offspring, compared to females which eggs were removed. Gene expression levels of both aromatases were independent of maternal care at the evaluated time points, even though they varied during the parental care period.
对于许多物种而言，亲代行为对于后代的生存至关重要。虽然硬骨鱼亲代行为的最终原因已得到广泛研究，但对其近因的了解相对较少。本研究的目的是分析尚未探索的、脑芳香化酶和性腺芳香化酶可能具有的双重作用，这两种酶分别负责在双亲自育丽鱼科鱼类双斑丽鲷（当地称为chanchita）亲代抚育期的不同阶段，将雄激素转化为雌激素。通过免疫组织化学，我们分析了脑芳香化酶的神经分布，并观察到它仅在前脑内，包括参与亲代行为调节的区域。接下来，我们分析了雌性chanchita在整个亲代抚育期内脑芳香化酶在脑中的基因表达以及性腺芳香化酶在卵巢中的基因表达。为了进一步表征与亲代抚育相关的生理环境，我们还评估了性类固醇水平（17β-雌二醇、睾酮和11-酮睾酮）和卵巢卵泡百分比。亲代行为的开始特异性地下调了性类固醇的合成和卵巢成熟率，与卵被移除的雌性相比，有后代的雌性类固醇水平下降超过10倍，成熟卵泡的检测延迟。在评估的时间点，两种芳香化酶的基因表达水平与亲代抚育无关，尽管它们在亲代抚育期内有所变化。
