Department of Neurobiology, Physiology and Behavior, University of California, Davis, United States.
Department of Neurobiology, Physiology and Behavior, University of California, Davis, United States.
Horm Behav. 2018 Apr;100:56-68. doi: 10.1016/j.yhbeh.2017.11.011. Epub 2018 Mar 20.
Stress is a well-known cause of reproductive dysfunction in many species, including birds, rodents, and humans, though males and females may respond differently. A powerful way to investigate how stress affects reproduction is by examining its effects on a biological system essential for regulating reproduction, the hypothalamic-pituitary-gonadal (HPG) axis. Often this is done by observing how a stressor affects the amount of glucocorticoids, such as cortisol or corticosterone, circulating in the blood and their relationship with a handful of known HPG-producing reproductive hormones, like testosterone and estradiol. Until now, we have lacked a full understanding of how stress affects all genomic activity of the HPG axis and how this might differ between the sexes. We leveraged a highly replicated and sex-balanced experimental approach to test how male and female rock doves (Columba livia) respond to restraint stress at the level of their transcriptome. Females exhibit increased genomic responsiveness to stress at all levels of their HPG axis as compared to males, and these responsive genes are mostly unique to females. Reasons for this may be due to fluctuations in the female endocrine environment over the reproductive cycle and/or their evolutionary history, including parental investment and the potential for maternal effects. Direct links between genome to phenome cause and effect cannot be ascertained at this stage; however, the data we report provide a vital genomic foundation on which sex-specific reproductive dysfunction and adaptation in the face of stress can be further experimentally studied, as well as novel gene targets for genetic intervention and therapy investigations.
压力是包括鸟类、啮齿动物和人类在内的许多物种生殖功能障碍的已知原因，尽管男性和女性的反应可能不同。研究压力如何影响生殖的一种有力方法是研究其对下丘脑-垂体-性腺 (HPG) 轴等调节生殖的生物系统的影响。通常，这是通过观察应激源如何影响血液中循环的糖皮质激素（如皮质醇或皮质酮）的量及其与一些已知的 HPG 产生生殖激素（如睾酮和雌二醇）的关系来完成的。到目前为止，我们还缺乏对压力如何影响 HPG 轴的所有基因组活动以及这种影响在性别之间可能有何不同的全面了解。我们利用高度复制和性别平衡的实验方法来测试雄性和雌性鸽子（Columba livia）在转录组水平对束缚应激的反应。与雄性相比，雌性在 HPG 轴的所有水平上对压力的基因组反应性更高，而这些反应性基因大多是雌性特有的。造成这种情况的原因可能是由于雌性内分泌环境在生殖周期中的波动，以及它们的进化历史，包括亲代投资和母体效应的潜力。在现阶段，无法确定从基因组到表型的因果关系；然而，我们报告的数据为面对压力时的性别特异性生殖功能障碍和适应提供了重要的基因组基础，可以进一步进行实验研究，以及遗传干预和治疗研究的新基因靶点。
