权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

MOLECULAR MECHANISM OF LIGHT REGULATED BIOLOGICAL CLOCK FOR REPRODUCTION OF ASCIDIANS.

海鞘繁殖的光调节生物钟的分子机制。

基本信息

批准号：
11480194
负责人：
TSUDA Motoyuki
金额：
$ 9.09万
依托单位：
HIMEJI INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11480194/
关键词：
ASCIDIAN LARVAE BRAIN PHOTOTAXIS RHODOPSIN BIOLOGICAL CLOCK G-PROTEIN GNRH REPRODUCTION

项目摘要

Since ascidians, a primitive chordate, spawn at a fixed latency period after sunrise, light must regulate a biological clock for reproduction in the ascidians. A retinal protein found in the cerebral ganglion of the ascidian is a candidate for the photoreceptor that drives the changes in gonadal activity of the gonadotropin-releasing hormone (GnRH) system. Photoresponses of the cerebral ganglion of ascidian, Halocynthia roretzi, were examined and two light-evoked responses recorded extracellularly, a light-evoked slow potential and light inhibition of high frequency spontaneous discharges. These results suggest that pacemaker signals of GnRH neurons are regulated by photoreceptor activation. Retinal proteins in the cerebral ganglion of the ascidian, Halocynthia roretzi, were successfully visualized and their localization was determined by the time-resolved fluorescence difference imaging method. Retinal proteins in the cerebral ganglion of adult Halocynthia roretzi, localized mainly at the surface of the anterodorsal root and the posterodorsal root. In the cross sections along the anteroposterio axis of the cerebral ganglion, the cells bearing retinal proteins were found in the peripheral cellular cortex mainly at the dorsal surface. Close localization of retinal protein and GnRH bearing cells suggests that retinal protein may trigger the biological clock for spawning in this ascidian.

由于海鞘是一种原始的脊索动物，在日出后的一个固定的潜伏期产卵，因此光必须调节海鞘繁殖的生物钟。在海鞘的脑神经节中发现的视网膜蛋白是驱动促性腺激素释放激素（GnRH）系统的性腺活性变化的光感受器的候选者。研究了海鞘（Halocynthia roretzi）脑神经节的光反应，并在细胞外记录了两种光诱发反应，即光诱发慢电位和光抑制高频自发放电。这些结果表明GnRH神经元的起搏信号受光感受器激活的调节。利用时间分辨荧光差分成像技术，成功地对海鞘（Halocynthia roretzi）脑神经节中的视网膜蛋白进行了可视化和定位。罗氏盐蛙成虫脑神经节中的视网膜蛋白，主要分布于前背根和后背根的表面。在脑神经节前后轴沿着横切面上，主要在背表面的外周细胞皮质中发现了含有视网膜蛋白的细胞。视网膜蛋白和GnRH轴承细胞的密切定位表明，视网膜蛋白可能触发生物钟产卵在这海鞘。