SYSTEM ANALYSIS OF PHYCOMYCES PHOLORESPONSES

藻类光反应的系统分析

• 批准号: 3277336
• 负责人: EDWARD D LIPSON
• 金额: $ 12.02万
• 依托单位: SYRACUSE UNIVERSITY AT SYRACUSE
• 依托单位国家: 美国
• 财政年份: 1981
• 资助国家: 美国
• 起止时间: 1981-07-01 至 1994-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3277336
• 关键词: Fungi; cell growth regulation; chromophore; ecology; environmental adaptation; fungal genetics; information system analysis; microorganism growth; mutant; nonvisual photoreceptor; nonvisual photosensitivity; photostimulus; second messengers; stimulus /response; videotape /videodisc

Photoreception and sensory transduction will be investigated for two blue- light responses of the unicellular sporangiophore of the fungus Phycomyces. Both phototropism and the light-growth response occur over an absolute operating range of 10 decades in light intensity from 10-9 to 10 W m-2. This range and the associated adaptation phenomena are similar to those that occur in visual receptor cells. The long term objective of the proposed research is to understand the processes by which a light stimulus is transduced into a cellular response, particularly in organisms with specific blue-light sensitivity associated with flavin chromophores. In Phycomyces, a model organism, genetic and physiological approaches can be effectively combined. Action spectra for phototropism and the light-growth response will be measured in different intensity ranges to characterize the low and high intensity photosystems of the sporangiophore. Phototropism action spectra will be obtained with continuous and pulsed light protocols. Experiments on kinetics of phototropism will be recorded with time-lapse video equipment and analyzed with the aid of an tracking machine using a novel method. The results will be compared with phototropic balance spectra to determine how each of the blue-light responses uses the components of the photoreceptor system. The recently discovered dependence of dark adaptation on dim, subliminal light will be pursued to help establish which photoreceptor mediates this effect, which is sensitive to green and red as well as blue light. System-identification experiments on the light-growth response will be continued on the tracking machine with Gaussian white noise and sum-of-sinusoids test stimuli to measure the dynamic and nonlinear aspects of this response. These experiments will involve both wild-type and mutant strains, and will be interpreted with analytical models for the kinetics of the photosensory transduction chain. A new theory, developed elsewhere, concerning light distribution around a sporangiophore will be tested experimentally by recording the azimuthal light pattern around a sporangiophore illuminated with a horizontal laser beam. This theory is important for interpretation of phototropism action spectra and is fundamental for theories of phototropism. Finally, cellular physiology methods will be applied to sporangiophores and protoplasts. Effector substances and indicator dyes will be introduced by direct uptake, injection, and electroporation; modified blue-light responses and effects will be monitored in preparations from wild type and mutant strains. These approaches are directed towards identifying molecular components and pathways associated with the blue light responses of Phycomyces.

光感受和感觉转导将研究两个蓝色- 真菌Phycomidae的单细胞孢子囊柄的光反应。 向光性和光生长反应都发生在绝对的 在10-9至10 W m-2的光强度下的10个十年的操作范围。 这个范围和相关的适应现象与那些 发生在视觉感受器细胞中。 的长远目标 一项被提议的研究是了解光刺激 转化为细胞反应，特别是在具有 与黄素发色团相关的特定蓝光敏感性。 在 藻类是一种模式生物，可以通过遗传和生理学方法进行研究。 有效结合。 向光性和光生长的作用光谱 将在不同强度范围内测量响应，以表征 孢子囊柄的低强度和高强度光系统。 光性 将用连续和脉冲光方案获得作用光谱。 向光性动力学实验将用延时摄影记录 视频设备和分析的帮助下，跟踪机使用 新颖的方法。 并将其结果与向光平衡进行了比较 光谱，以确定每个蓝光响应如何使用 感光系统的组成部分。 最近发现的依赖性 暗适应的暗，潜意识光将寻求帮助， 确定哪种感光体介导这种效应，哪种感光体对 绿色和红色以及蓝色光。 系统辨识实验 光生长反应将在跟踪机上继续， 高斯白色噪声和正弦曲线之和测试刺激来测量 动态和非线性方面的这种反应。 这些实验将 涉及野生型和突变株，并将解释为 光敏转导链动力学的分析模型。 一个新的理论，在其他地方发展，关于周围的光分布， 孢子囊梗将通过记录方位角进行实验测试 用水平激光照射孢子囊柄周围的光图案 梁 这一理论对解释向光性作用具有重要意义 光谱，是向光性理论的基础。 最后，细胞 将生理学方法应用于孢子囊和原生质体。 效应物质和指示染料将通过直接摄取引入， 注射和电穿孔;修饰的蓝光响应和作用 将在野生型和突变株制备物中进行监测。 这些 这些方法涉及鉴定分子组分， 与Phycommonium的蓝光反应相关的途径。