Neuronal control of locomotor handedness in Drosophila
Neuronal control of locomotor handedness in Drosophila
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DOI：
10.1073/pnas.1500804112
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发表时间：
2015-05-26
影响因子：
11.1
通讯作者：
de Bivort, Benjamin L.
中科院分区：
文献类型：
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作者：
Buchanan, Sean M.;Kain, Jamey S.;de Bivort, Benjamin L.
即使在基本相同的环境中长大，基因相同的个体在生理、形态和行为上也表现出多样性，但对这种差异的基础几乎没有机械上的理解。在这里，我们调查了黑腹果蝇是否在运动行为上表现出个体之间的差异。我们开发了一种新的高通量平台，能够同时测量数百只苍蝇的探索行为。通过这种方法，我们发现，在探索性行走过程中，个别果蝇在左与右的运动选择上表现出显著的偏见，一些果蝇强烈地倾向于左偏或右偏。这一特性在所有被检测的基因类型中都存在，包括野生种群和近交系等基因实验室菌株。个体苍蝇的偏见在它们的一生中持续存在，并且是不可遗传的：即，两个偏左的个体交配不会产生偏左的后代。这种运动性利手与其他不对称性无关，如肠道扭转、腿长不对称和折翼偏好等。利用转基因和突变体，我们发现运动利手的大小受中央复合体内的柱状神经元控制，中央复合体是一个与运动规划和执行有关的大脑区域。当这些神经元被沉默时，探索的偏侧性增加，具有更多的极端左倾和右倾。这一观察有趣地暗示，大脑可能能够动态地调节行为个性。
Genetically identical individuals display variability in their physiology, morphology, and behaviors, even when reared in essentially identical environments, but there is little mechanistic understanding of the basis of such variation. Here, we investigated whether Drosophila melanogaster displays individual-to-individual variation in locomotor behaviors. We developed a new high-throughout platform capable of measuring the exploratory behavior of hundreds of individual flies simultaneously. With this approach, we find that, during exploratory walking, individual flies exhibit significant bias in their left vs. right locomotor choices, with some flies being strongly left biased or right biased. This idiosyncrasy was present in all genotypes examined, including wild-derived populations and inbred isogenic laboratory strains. The biases of individual flies persist for their lifetime and are non-heritable: i.e., mating two left-biased individuals does not yield left-biased progeny. This locomotor handedness is uncorrelated with other asymmetries, such as the handedness of gut twisting, leg-length asymmetry, and wing-folding preference. Using transgenics and mutants, we find that the magnitude of locomotor handedness is under the control of columnar neurons within the central complex, a brain region implicated in motor planning and execution. When these neurons are silenced, exploratory laterality increases, with more extreme leftiness and rightiness. This observation intriguingly implies that the brain may be able to dynamically regulate behavioral individuality.