Social regulation of cortisol receptor gene expression
Social regulation of cortisol receptor gene expression
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DOI：
10.1242/jeb.104430
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发表时间：
2014-09-01
影响因子：
2.8
通讯作者：
Fernald, Russell D.
中科院分区：
文献类型：
--
作者：
Korzan, Wayne J.;Grone, Brian P.;Fernald, Russell D.
在许多社会物种中，个体影响同种的生殖能力。在一个充分研究的非洲慈鲷鱼种，Astatolapia burtoni，男性要么占主导地位（D）和生殖能力或非主导地位（ND）和生殖抑制的促性腺激素释放激素（GnRH 1）释放减少，退化的性腺，雄激素水平较低，皮质醇水平升高。在这里，我们询问雄激素和皮质醇水平是否可以调节这种生殖抑制。博氏Astatolipia burtoni有四种糖皮质激素受体（GR 1a，GR 1b，GR 2和MR），由三个基因编码，和两种雄激素受体（AR α和AR β），由两个基因编码。我们以前的研究表明，AR α和AR β在调节生殖的视前区（POA）的GnRH 1神经元中表达，并且这些受体的mRNA水平受社会地位的调节。在这里，我们表明，GR1，GR2和MR的mRNA也表达在促性腺激素释放激素1神经元的POA，揭示潜在的机制，雄激素和皮质醇影响生殖能力。我们测量AR，MR和GR mRNA的表达水平在一个显微解剖区域的POA含有GnRH 1神经元，比较D和ND男性。采用定量PCR（qPCR）方法，我们发现D型雄鼠POA中AR α、MR、总GR 1a和GR 2的mRNA水平均高于ND型雄鼠。相比之下，ND男性有显着较高水平的GR1b mRNA，受体亚型与皮质醇的转录反应降低。通过这种新的受体类型的调节，神经元在一个ND男性的POA将较少受皮质醇的典型的低地位的较高水平的影响，这表明GR受体类型的变化作为一个潜在的适应机制，以介导高皮质醇水平在社会抑制。
In many social species, individuals influence the reproductive capacity of conspecifics. In a well-studied African cichlid fish species, Astatotilapia burtoni, males are either dominant (D) and reproductively competent or non-dominant (ND) and reproductively suppressed as evidenced by reduced gonadotropin releasing hormone (GnRH1) release, regressed gonads, lower levels of androgens and elevated levels of cortisol. Here, we asked whether androgen and cortisol levels might regulate this reproductive suppression. Astatotilapia burtoni has four glucocorticoid receptors (GR1a, GR1b, GR2 and MR), encoded by three genes, and two androgen receptors (AR alpha and AR beta), encoded by two genes. We previously showed that AR alpha and AR beta are expressed in GnRH1 neurons in the preoptic area (POA), which regulates reproduction, and that the mRNA levels of these receptors are regulated by social status. Here, we show that GR1, GR2 and MR mRNAs are also expressed in GnRH1 neurons in the POA, revealing potential mechanisms for both androgens and cortisol to influence reproductive capacity. We measured AR, MR and GR mRNA expression levels in a microdissected region of the POA containing GnRH1 neurons, comparing D and ND males. Using quantitative PCR (qPCR), we found D males had higher mRNA levels of AR alpha, MR, total GR1a and GR2 in the POA compared with ND males. In contrast, ND males had significantly higher levels of GR1b mRNA, a receptor subtype with a reduced transcriptional response to cortisol. Through this novel regulation of receptor type, neurons in the POA of an ND male will be less affected by the higher levels of cortisol typical of low status, suggesting GR receptor type change as a potential adaptive mechanism to mediate high cortisol levels during social suppression.