Changes in circuit motif during evolution of a species-specific behavior.

物种特异性行为进化过程中电路基序的变化。

• 批准号: RGPIN-2017-04781
• 负责人: Oyama, Tomoko
• 金额: $ 3.79万
• 依托单位: McGill University
• 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=745842
• 关键词: Changes; circuit; motif; during; evolution

Evolution has generated an enormous variety of morphological, physiological, and behavioral traits in animals. Decades of research have shown that variation in the regulatory regions of particular genes is associated with species differences in morphology (e.g., wing pattern). But how do behaviors evolve in different directions in species equipped with similar neurons and molecular components? Solving these mysteries requires an understanding of the relationship between evolutionarily adaptive changes in behavior and structural/functional changes in neural circuits.Fruit fly (Drosophila) larvae are useful for this purpose because 1) the Drosophila genus consists of many closely related species that exhibit a wide range of behaviors; 2) they are small enough to generate electron microscope images of the entire nervous system; and 3) the genetic tools and high-throughput behavior analysis techniques available for D. melanogaster make it possible to manipulate single neuron types to understand their function(s) in neural circuits and behavior.Escape behaviors, which likely evolved under intense evolutionary pressures given their importance for survival, offer a particularly good opportunity to understand behavioral evolution. D. melanogaster larvae roll when attacked by a parasitic wasp. In the laboratory, a nociceptive stimulus triggers rolling. The core circuitry underlying this behavior has recently been mapped out. Preliminary data also show that the probability of rolling varies widely across several closely related Drosophila species. This sets the stage for an exploratory analysis of the neural changes associated with changes in a specific behavior.This proposal will identify the synapse- and circuit-level changes in structure/function that underlie the divergence of rolling probability in a well-defined sensorimotor circuit. Aim 1 will compare larval escape behaviors in detail across different Drosophila species. Aim 2 will reconstruct the circuitry underlying rolling, with physiological imaging experiments to test for correlations among circuitry, physiology, and behavior. The results should reveal circuit motifs required for adjusting rolling probability, and how variation in the structural/functional properties of circuitry contributes to behavioral evolution in general. Our long-term goal is to understand how changes in these features transform behavior at the circuit, cellular, and molecular levels. Such an achievement would constitute one of the first demonstrations of what the renowned sociobiologist E. O. Wilson called consiliencean understanding of behavioral evolution that integrates knowledge vertically across multiple levels of analysis, from molecules at the bottom, to behavior at the top.

进化使动物产生了多种多样的形态、生理和行为特征。数十年的研究表明，特定基因调控区域的变异与物种形态差异（例如翅膀图案）有关。但是，在具有相似神经元和分子成分的物种中，行为如何向不同方向进化呢？解决这些谜团需要了解行为的进化适应性变化与神经回路的结构/功能变化之间的关系。果蝇（果蝇）幼虫对于此目的很有用，因为1）果蝇属由许多密切相关的物种组成，表现出广泛的行为； 2）它们足够小，可以生成整个神经系统的电子显微镜图像； 3）可用于黑腹果蝇的遗传工具和高通量行为分析技术使得操纵单个神经元类型以了解其在神经回路和行为中的功能成为可能。鉴于其对生存的重要性，逃避行为可能是在强烈的进化压力下进化的，为理解行为进化提供了特别好的机会。黑腹果蝇幼虫在受到寄生黄蜂攻击时会打滚。在实验室中，伤害性刺激会引发翻滚。这种行为背后的核心电路最近已经被绘制出来。初步数据还表明，几种密切相关的果蝇物种的滚动概率差异很大。这为探索性分析与特定行为变化相关的神经变化奠定了基础。该提案将识别结构/功能中的突触和电路级变化，这些变化是明确定义的感觉运动电路中滚动概率发散的基础。目标 1 将详细比较不同果蝇物种的幼虫逃逸行为。目标 2 将通过生理成像实验重建滚动的电路，以测试电路、生理和行为之间的相关性。结果应该揭示调整滚动概率所需的电路主题，以及电路的结构/功能特性的变化如何有助于一般的行为进化。 我们的长期目标是了解这些特征的变化如何改变电路、细胞和分子水平的行为。这样的成就将构成著名社会生物学家 E. O. Wilson 所谓的行为进化的一致性理解的首批示范之一，这种理解将跨多个分析层次的知识垂直整合，从底部的分子到顶部的行为。