Structure of ocellus photoreceptors in the ascidian Ciona intestinalis larva as revealed by an anti-arrestin antibody
Structure of ocellus photoreceptors in the ascidian Ciona intestinalis larva as revealed by an anti-arrestin antibody
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DOI：
10.1002/neu.20197
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发表时间：
2005-12-01
期刊：
影响因子：
--
通讯作者：
Nakagawa, M
中科院分区：
文献类型：
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作者：
Horie, T;Orii, H;Nakagawa, M
虽然已经有几个研究的ocellus光感受器在海鞘蝌蚪幼虫的结构，使用电子显微镜，这些感光细胞的整体结构，特别是轴突的投射部位，还没有完全揭示。感光细胞的数量也是有争议的。在这里，海鞘玻璃海鞘幼虫的单眼光感受器的整个结构，揭示了通过使用抗抑制蛋白（抗Ci-Arr）抗体。30个感光细胞的胞体覆盖在单眼色素细胞的右侧，其外节穿过色素细胞进入色素杯。光感受器细胞的轴突在腹后方向捆绑在一起，形成一条向中线延伸的神经束。神经终末在后感觉囊（SV）的中线前后分叉。在胚胎中期尾芽期，Ci-1基因在整个SV中表达，当发生单眼色素沉着时，它变得仅限于附近或单眼色素。同时，首次检测到Ci-Arr蛋白，提示感光细胞开始分化。还使用抗Ci-Arr抗体研究了孵化后感光细胞的发育。孵化后3小时，感光末梢开始分叉，然后扩展。先前的行为分析表明，幼虫没有响应的逐步减少的光，直到孵化后2小时，然后光反应变得强大。因此，我们的研究结果表明，感光末梢的生长是至关重要的幼虫成为光响应。(c)2005 Wiley Periodicals，Inc.
Although there have been several studies on the structure of the ocellus photoreceptors in ascidian tadpole larvae using electron microscopy, the overall structure of these photoreceptor cells, especially the projection sites of the axons, has not been revealed completely. The number of photoreceptor cells is also controversial. Here, the whole structure of the ocellus photoreceptors in the larvae of the ascidian Ciona intestinalis was revealed by using an anti-arrestin (anti-Ci-Arr) antibody. The cell bodies of 30 photoreceptor cells covered the right side of the ocellus pigment cell and their outer segments extended through the pigment cell into the pigment cup. The axons of the photoreceptor cells were bundled together ventro-posteriorly in a single tract extending towards the midline. The nerve terminals diverged antero-posteriorly at the midline of the posterior sensory vesicle (SV). The Ci-arr gene was expressed throughout the SV at the embryonic mid-tail-bud stage and it became restricted to the neighborhood or the ocellus pigment when ocellus pigmentation occurred. At the same time, the Ci-Arr protein was first detected, suggesting that the photoreceptor cells began to differentiate. The development of photoreceptor cells after hatching was also investigated using the anti-Ci-Arr antibody. Three hours after hatching, the photoreceptor terminals began to ramify and then expanded. Previous behavioral analysis showed that the larvae did not respond to the step-down of light until 2 h after hatching and then the photoresponse became robust. Accordingly, our results suggest that growth of the photoreceptor terminal is critical for the larvae to become photoresponsive. (c) 2005 Wiley Periodicals, Inc.