科學家繪製出果蠅視覺系統的發育圖譜
作者:
小柯機器人發布時間:2020/11/8 22:29:57
美國紐約大學Claude Desplan、Nikolaos Konstantinides等研究人員合作繪製出果蠅視覺系統的發育圖譜,並揭示神經元的多樣性和趨同性。這一研究成果於2020年11月4日在線發表在國際學術期刊《自然》上。
通過對果蠅視神經葉轉錄組多樣性的完整描述,研究人員報導了對大腦發育的見解。研究人員在成年期和五個蛹階段獲得了275,000個單細胞的轉錄組,並建立了機器學習框架,可在開發過程中的所有時間點將它們分配給近200種細胞類型。研究人員發現了兩大類神經元群體,它們在發育過程中包裹了神經氈,但是在成年前就死亡了,還有兩類神經元亞型,它們通過整個發育過程中的Wnt差異信號來分隔背側和腹側視覺迴路。
此外,研究人員表明,相同類型但間隔數天產生的神經元轉錄組在產生後不久就會同步。在突觸發生過程中,研究人員還解析了神經元亞型,儘管其形態和連接性差異很大,但它們在成年人中趨同為難以區分的轉錄組譜。這個數據集幾乎完全說明了果蠅視神經葉的已知神經元多樣性,並可成為理解不同物種間大腦發育的範例。
據悉,解密如何建立和維持神經元多樣性需要在整個發育過程中對神經元基因表達有詳細的了解。與哺乳動物的大腦相反,果蠅視神經葉及其連接體具有大量神經元多樣性,並已經幾乎完全被表徵。但是,缺乏這種神經元多樣性的分子表徵,特別是在發育過程中。
附:英文原文
Title: Neuronal diversity and convergence in a visual system developmental atlas
Author: Mehmet Neset zel, Flix Simon, Shadi Jafari, Isabel Holguera, Yen-Chung Chen, Najate Benhra, Rana Naja El-Danaf, Katarina Kapuralin, Jennifer Amy Malin, Nikolaos Konstantinides, Claude Desplan
Issue&Volume: 2020-11-04
Abstract: Deciphering how neuronal diversity is established and maintained requires a detailed knowledge of neuronal gene expression throughout development. In contrast to mammalian brains1,2, the large neuronal diversity of the Drosophila optic lobe3 and its connectome4–6 are almost completely characterized. However, a molecular characterization of this neuronal diversity, particularly during development, has been lacking. Here we present insights into brain development through a nearly complete description of the transcriptomic diversity of the optic lobes of Drosophila. We acquired the transcriptome of 275,000 single cells at adult and at five pupal stages, and built a machine-learning framework to assign them to almost 200 cell types at all time points during development. We discovered two large neuronal populations that wrap neuropils during development but die just before adulthood, as well as neuronal subtypes that partition dorsal and ventral visual circuits by differential Wnt signalling throughout development. Moreover, we show that the transcriptomes of neurons that are of the same type but are produced days apart become synchronized shortly after their production. During synaptogenesis we also resolved neuronal subtypes that, although differing greatly in morphology and connectivity, converge to indistinguishable transcriptomic profiles in adults. Our datasets almost completely account for the known neuronal diversity of the Drosophila optic lobes, and serve as a paradigm to understand brain development across species. The neuronal diversity of the Drosophila optic lobe is described throughout pupal development by single-cell sequencing, leading to the discovery of transient extrinsic neurons and a dorsoventral asymmetry of the visual circuits.
DOI: 10.1038/s41586-020-2879-3
Source: https://www.nature.com/articles/s41586-020-2879-3