Environmental sex determination, alternative male morphs, and the biological basis of personality

环境性别决定、另类男性变形以及人格的生物学基础

• 批准号: RGPIN-2018-05704
• 负责人: Hurd, Peter
• 金额: $ 5.83万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=764043
• 关键词: Environmental; sex; determination; alternative; male

My lab is focused upon understanding the biological basis of personality-like traits in general, and aggressiveness in particular. We examine the evolution, development and neuroendocrinological mechanisms underlying such individual variation. We aim to understand the evolutionary costs and benefits maintaining variation in behaviour.Variation in prenatal testosterone exposure during development is thought to permanently organize many behaviours throughout adulthood, particularly those that show sex differences, creating a spectrum of brain sex. Empirical evidence from both human and non-human animals suggests that the strength of sexual differentiation can variably masculinize eventual adult morphology and behaviour alike. Most of this work is purely correlational. Experimental manipulations, such as hormone treatments during development, do not necessarily inform us about the selective pressures on variation if the phenotypes produced are outside the range seen in recent ancestral history.To create such real-world range variation, I shall experimentally manipulate sex in an ecologically realistic manner by manipulating water chemistry in a species of cichlid fish with environmental sex determination. The intent is to create variation in the degree of mascuilinization of individuals. Lower pH during the first 30 days produces more males in adulthood, and more of those males are of the more aggressive, haremic-tending morph, and fewer are of the monogamy-tending morph. Work in many other species with environmental sex determination suggests that methylation of the aromatase gene promoter is associated with the environmental factor and a key part of sex determination. My preliminary data suggests that early pH manipulations influence the methylation of CpG sites in the promoter for both the brain and gonadal version of the aromatase genes. I shall extend this work to examine whether this sex determination pathway is also involved in determining male morph, and individual differences within morphs and sexes. I will examine the effects of these manipulations, and differences between alternative male morphs, in terms of both behaviour and brain. The brain's social behaviour network is a set of brain circuits which is highly conserved across vertebrates. We can experimentally induce changes in these brain regions, then study the effects on social behaviour in fish that should be of direct relevance to humans. That the sex of the brain lies on a continuous spectrum between a male and female extreme is an idea with very broad applicability and relevance. Many aspects of autism can be understood as a pathological hypermasculinization of the brain, as many aspects of psychosis can be understood as a pathological hyperfeminization of the brain. Between these extremes lies a continuous range of cognitive abilities and behavioural tendencies, each one with it's strengths and weaknesses.

我的实验室专注于了解一般人格特征的生物学基础，特别是攻击性。我们研究了这种个体差异的进化，发展和神经内分泌机制。我们的目标是了解维持行为变异的进化成本和收益。在发育过程中，产前睾酮暴露的变化被认为会永久地组织整个成年期的许多行为，特别是那些表现出性别差异的行为，创造出一系列大脑性别。来自人类和非人类动物的经验证据表明，性别分化的强度可能会使最终的成年形态和行为变得男性化。 大多数的工作是纯粹的相关性。实验操作，如激素治疗过程中的发展，不一定告诉我们的选择压力的变化，如果产生的表型是在最近的祖先history.To创建这样的现实世界的范围内的变化，我将实验操纵性别在一个生态现实的方式操纵水化学在一个物种的慈鲷鱼与环境的性别决定。其目的是在个人的男性化程度上创造差异。在前30天较低的pH值产生更多的男性在成年期，和更多的这些男性是更积极的，haremic-tending变形，更少的是一夫一妻制倾向的变形。在许多其他物种中的工作与环境性别决定表明，芳香化酶基因启动子的甲基化与环境因素和性别决定的关键部分。我的初步数据表明，早期pH值的操纵影响的CpG位点的甲基化启动子的大脑和性腺的芳香化酶基因的版本。 我将扩展这项工作，以检查这种性别决定途径是否也参与决定男性形态，以及形态和性别内的个体差异。 我将从行为和大脑两个方面研究这些操纵的效果，以及不同男性变体之间的差异。 大脑的社会行为网络是一组在脊椎动物中高度保守的大脑回路。我们可以通过实验诱导这些大脑区域的变化，然后研究对鱼类社会行为的影响，这应该与人类直接相关。大脑的性别在男性和女性极端之间是一个连续的光谱，这是一个具有非常广泛适用性和相关性的想法。 自闭症的许多方面可以理解为大脑的病理性过度男性化，因为精神病的许多方面可以理解为大脑的病理性过度女性化。 在这两个极端之间，存在着一系列连续的认知能力和行为倾向，每一种都有其长处和短处。