Erclik Ted, Li Xin, Courgeon Maximilien, Bertet Claire, Chen Zhenqing, Baumert Ryan, Ng June, Koo Clara, Arain Urfa, Behnia Rudy, del Valle Rodriguez Alberto, Senderowicz Lionel, Negre Nicolas, White Kevin P, Desplan Claude
Department of Biology, New York University, New York, New York 10003, USA.
Department of Biology, University of Toronto at Mississauga, Mississauga, Ontario L5L-1C6, Canada.
Nature. 2017 Jan 19;541(7637):365-370. doi: 10.1038/nature20794. Epub 2017 Jan 11.
In the Drosophila optic lobes, 800 retinotopically organized columns in the medulla act as functional units for processing visual information. The medulla contains over 80 types of neuron, which belong to two classes: uni-columnar neurons have a stoichiometry of one per column, while multi-columnar neurons contact multiple columns. Here we show that combinatorial inputs from temporal and spatial axes generate this neuronal diversity: all neuroblasts switch fates over time to produce different neurons; the neuroepithelium that generates neuroblasts is also subdivided into six compartments by the expression of specific factors. Uni-columnar neurons are produced in all spatial compartments independently of spatial input; they innervate the neuropil where they are generated. Multi-columnar neurons are generated in smaller numbers in restricted compartments and require spatial input; the majority of their cell bodies subsequently move to cover the entire medulla. The selective integration of spatial inputs by a fixed temporal neuroblast cascade thus acts as a powerful mechanism for generating neural diversity, regulating stoichiometry and the formation of retinotopy.
在果蝇的视叶中，髓质内800个按视网膜拓扑结构组织的柱体作为处理视觉信息的功能单元。髓质包含80多种神经元，可分为两类：单柱神经元每柱一个，而多柱神经元联系多个柱体。我们在此表明，来自时间轴和空间轴的组合输入产生了这种神经元多样性：所有神经母细胞随时间改变命运以产生不同的神经元；产生神经母细胞的神经上皮也通过特定因子的表达被细分为六个区室。单柱神经元在所有空间区室中独立于空间输入产生；它们支配其产生部位的神经纤维网。多柱神经元在有限的区室中产生数量较少，并且需要空间输入；它们大多数的细胞体随后移动以覆盖整个髓质。因此，由固定的时间性神经母细胞级联对空间输入进行选择性整合，是产生神经多样性、调节化学计量以及形成视网膜拓扑结构的强大机制。
