近日，美国纽约大学Claude Desplan及其小组揭示了果蝇视觉系统中的随机和确定性分化之间的协调作用。2019年10月3日，这一研究结果在线发表于国际学术期刊《科学》。

研究人员确定了R7神经元的主要靶标亚型，Dm8神经元，每个都特定于R7s的不同亚型。 Dm8亚型由独立的神经元祖细胞过量产生，并独立于R7。与它们的同源R7匹配后，多余的Dm8通过细胞凋亡消除。两个相互作用的细胞粘附分子Dpr11和DIPγ对于其中一个突触对的匹配至关重要。这些机制可以实现R7/Dm8的定性和定量匹配，并使得R7做出的随机选择传播到大脑。

研究人员介绍，感觉系统使用随机命运分化来增加其神经元类型库。这些随机决定如何与其靶标的发育相协调是未知的。在果蝇视网膜中，两种对紫外线敏感的R7感光体亚型是随机分化的。相反，它们在大脑中的靶标是通过确定性程序分化的。

附：英文原文

Title: Coordination between stochastic and deterministic specification in the Drosophila visual system

Author: Maximilien Courgeon, Claude Desplan

Issue&Volume: 2019/10/03

Abstract: Sensory systems use stochastic fate specification to increase their repertoire of neuronal types. How these stochastic decisions are coordinated with the development of their targets is unknown. In the Drosophila retina, two subtypes of UV-sensitive R7-photoreceptors are stochastically specified. In contrast, their targets in the brain are specified through a deterministic program. Here, we identify subtypes of the main target of R7, the Dm8 neurons, each specific to the different subtypes of R7s. Dm8 subtypes are produced in excess by distinct neuronal progenitors, independently from R7. Following matching with their cognate R7, supernumerary Dm8s are eliminated by apoptosis. Two interacting cell adhesion molecules, Dpr11 and DIPγ, are essential for the matching of one of the synaptic pairs. These mechanisms allow the qualitative and quantitative matching of R7/Dm8 and permit the stochastic choice made in R7 to propagate to the brain.

DOI: 10.1126/science.aay6727

Source: https://science.sciencemag.org/content/early/2019/10/02/science.aay6727