瑞士洛桑大学Richard Benton和Thomas O. Auer研究团队合作在研究中取得进展。他们发现嗅觉感受器和电路演化促进宿主特殊化。论文于3月4日在线发表于《自然》。
在该研究中，研究人员研发了一种神经遗传模型，即果蝇（Drosophila sechellia），该物种与其近亲黑腹果蝇（Drosophila melanogaster）相比在行为上表现出明显差异，这与其对诺丽果（Morinda citrifolia）的特异性识别有关。
使用钙成像方法，研究人员可以确定D. sechellia的嗅觉系统，该系统可以检测诺丽果宿主释放的挥发物。利用突变分析，研究人员发现不同的嗅觉受体在对诺丽菌素的长距离和短距离吸引中都起着作用。
跨物种等位基因转移实验表明，调节这些受体之一对于宿主寻找特定物种很重要。研究人员揭示了这种功能改变的分子决定因素，并表征了其进化起源和对行为的重要性。通过对D. sechellia脑进行电路追踪，研究人员发现受体的适应性伴随着对神经元以及特定物种中央投射模式感觉池的增加。
这项工作揭示物种之间的行为差异与分子、生理和解剖学等特征的积累有关，并建立了一个可用于研究物种形成和神经系统进化的模型。
据介绍，人类对动物行为的进化知之甚少。尽管行为的种间差异与神经系统结构和功能之间存在许多相关性，但对于这些行为差异的遗传基础仍知之甚少。
附：英文原文
Title: Olfactory receptor and circuit evolution promote host specialization
Author: Thomas O. Auer, Mohammed A. Khallaf, Ana F. Silbering, Giovanna Zappia, Kaitlyn Ellis, Raquel lvarez-Ocaa, J. Roman Arguello, Bill S. Hansson, Gregory S. X. E. Jefferis, Sophie J. C. Caron, Markus Knaden, Richard Benton
Issue&Volume: 2020-03-04
Abstract: The evolution of animal behaviour is poorly understood1,2. Despite numerous correlations between interspecific divergence in behaviour and nervous system structure and function, demonstrations of the genetic basis of these behavioural differences remain rare3,4,5. Here we develop a neurogenetic model, Drosophila sechellia, a species that displays marked differences in behaviour compared to its close cousin Drosophila melanogaster6,7, which are linked to its extreme specialization on noni fruit (Morinda citrifolia)8,9,10,11,12,13,14,15,16. Using calcium imaging, we identify olfactory pathways in D. sechellia that detect volatiles emitted by the noni host. Our mutational analysis indicates roles for different olfactory receptors in long- and short-range attraction to noni, and our cross-species allele-transfer experiments demonstrate that the tuning of one of these receptors is important for species-specific host-seeking. We identify the molecular determinants of this functional change, and characterize their evolutionary origin and behavioural importance. We perform circuit tracing in the D. sechellia brain, and find that receptor adaptations are accompanied by increased sensory pooling onto interneurons as well as species-specific central projection patterns. This work reveals an accumulation of molecular, physiological and anatomical traits that are linked to behavioural divergence between species, and defines a model for investigating speciation and the evolution of the nervous system.
DOI: 10.1038/s41586-020-2073-7
Source: https://www.nature.com/articles/s41586-020-2073-7
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
