Evolutionary shifts in the developmental control of neuron number

神经元数量发育控制的进化转变

• 批准号: 2750262
• 金额: --
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2750262
• 关键词: Evolutionary; shifts; developmental; control; neuron

Brain size varies massively across species, often largely explained by variation in the production of neurons during development. Although we have some knowledge of the developmental mechanisms controlling neuron production in certain well studied species, we are only beginning to explore how these developmental mechanisms change to facilitate the evolution of neuron number. Understanding the proximate basis of neural variation is critical for diverse questions in evolutionary neuroscience, from identifying potential constraints and trade-offs in brain evolution, to explore relationships between neural traits and behavioural variation. This project aims to tackle these questions using Heliconiini, a diverse tribe of Neotropical butterflies, as a study system. We have recently shown that one region of the brain that has particular importance in learning and memory, the mushroom bodies, varies by over 25X across Heliconiini butterflies. This extreme variation is driven by a massive expansion in the number of Kenyon cells, neurons that form the mushroom body. We now want to understand how this variation in Kenyon cell number is determined by changes in the developmental control of neurogenesis across species. The primary goals of the project are to test the role of four processes, all of which could alter cell production, in shaping Kenyon cell number across Heliconiini: i) increased neuroblast number at the onset of neurogenesis, ii) accelerated cell-cycle rates during neurogenesis, iii) extension in the duration of neurogenesis, iv) reduced or delayed patterns of apoptosis of neuroblasts. This work will be performed by comparing patterns of development across species which vary in Kenyon cell in known ways. It will form the foundation of our understanding of how Kenyon cell neurogenesis varies across species. Subsequent work will use this foundation to study the functional effects of candidate genes identified by our lab as regulators of mushroom body evolution.

不同物种的大脑大小差异很大，这在很大程度上可以用发育过程中神经元产生的差异来解释。虽然我们对某些物种控制神经元产生的发育机制有一些了解，但我们才刚刚开始探索这些发育机制如何改变以促进神经元数量的进化。了解神经变异的近似基础对于进化神经科学中的各种问题至关重要，从识别大脑进化中的潜在限制和权衡，到探索神经特征和行为变异之间的关系。该项目旨在利用Heliconiini（一种不同的新热带蝴蝶部落）作为研究系统来解决这些问题。我们最近发现，大脑中对学习和记忆特别重要的一个区域，蘑菇体，在蝴蝶之间的差异超过25倍。这种极端的变异是由凯尼恩细胞（形成蘑菇体的神经元）数量的大量增加所驱动的。我们现在想要了解这种肯尼恩细胞数量的变化是如何由跨物种神经发生的发育控制的变化决定的。该项目的主要目标是测试四个过程的作用，所有这些过程都可以改变细胞的产生，在Heliconiini中形成Kenyon细胞数量：i)在神经发生时增加神经母细胞数量，ii)在神经发生期间加速细胞周期速率，iii)延长神经发生的持续时间，iv)减少或延迟神经母细胞的凋亡模式。这项工作将通过比较不同物种的发育模式来完成，这些模式以已知的方式在凯尼恩细胞中有所不同。它将为我们理解不同物种间肯尼恩细胞神经发生的差异奠定基础。后续的工作将利用这一基础来研究我们实验室鉴定的候选基因作为蘑菇体进化调节因子的功能效应。