Switch of rhodopsin expression in terminally differentiated Drosophila sensory neurons
Switch of rhodopsin expression in terminally differentiated Drosophila sensory neurons
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DOI：
10.1038/nature07062
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发表时间：
2008-07-24
期刊：
影响因子：
64.8
通讯作者：
Desplan, Claude
中科院分区：
文献类型：
--
作者：
Sprecher, Simon G.;Desplan, Claude
感觉神经元的特异性需要一个感觉受体基因的限制性表达，并排除给定细胞内的所有其他基因。在果蝇视网膜中，光感受器的功能特性依赖于光敏视紫红质（Rhs）。更简单的幼虫眼睛（Bolwig器官）由大约12个光感受器组成，其中8个是绿色敏感的（Rh6）和4个蓝色敏感的（Rh5）（1）。幼虫的眼睛变成由四个绿色敏感（Rh6）光感受器组成的成年视网膜外“眼睛”（2，3）。在这里，我们表明，在变态过程中，所有的Rh6光感受器死亡，而Rh5光感受器开关命运关闭Rh5，然后打开Rh6的表达。这种转换的发生不会导致指定幼虫感光器亚型的转录因子程序发生明显变化。我们还表明，转录因子无意义（Sens）介导的非常不同的细胞行为的Rh5和Rh6光感受器。Sens仅限于Rh5光感受器，并且必须从Rh6光感受器中排除，以允许它们在变态时死亡。最后，我们表明，蜕皮激素受体（EcR）的功能自主的幼虫Rh6光感受器的死亡和Rh5光感受器的感官开关，以表达Rh6。这种功能性的、终末分化的神经元的命运开关提供了一个新的、意想不到的硬连线感觉可塑性的例子。
Specificity of sensory neurons requires restricted expression of one sensory receptor gene and the exclusion of all others within a given cell. In the Drosophila retina, functional identity of photoreceptors depends on light-sensitive Rhodopsins (Rhs). The much simpler larval eye (Bolwig organ) is composed of about 12 photoreceptors, eight of which are green-sensitive (Rh6) and four bluesensitive (Rh5)(1). The larval eye becomes the adult extraretinal 'eyelet' composed of four green-sensitive (Rh6) photoreceptors(2,3). Here we show that, during metamorphosis, all Rh6 photoreceptors die, whereas the Rh5 photoreceptors switch fate by turning off Rh5 and then turning on Rh6 expression. This switch occurs without apparent changes in the programme of transcription factors that specify larval photoreceptor subtypes. We also show that the transcription factor Senseless (Sens) mediates the very different cellular behaviours of Rh5 and Rh6 photoreceptors. Sens is restricted to Rh5 photoreceptors and must be excluded from Rh6 photoreceptors to allow them to die at metamorphosis. Finally, we show that Ecdysone receptor (EcR) functions autonomously both for the death of larval Rh6 photoreceptors and for the sensory switch of Rh5 photoreceptors to express Rh6. This fate switch of functioning, terminally differentiated neurons provides a novel, unexpected example of hard-wired sensory plasticity.