SYSTEM ANALYSIS OF PHYCOMYCES PHOTORESPONSES

藻类光响应的系统分析

• 批准号: 3277338
• 负责人: EDWARD D LIPSON
• 金额: $ 10.29万
• 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 1990-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3277338
• 关键词: Fungi; environmental adaptation; information system analysis; microorganism growth; mutant; nonvisual photoreceptor; photobiology; spectrometry; stimulus /response; videotape /videodisc

Photoreception and sensory transduction will be investigated in the fungus Phycomyces, in connection with its phototropism and other blue light responses. The long term objective is to understand, at the cellular and molecular levels, the processes by which a stimulus such as light is transduced into a cellular response. The unicellular sporangiophore of Phycomyces serves as a model system for primary receptor cells. The absolute operating range of 10-10:1 in light intensity and the kinetics of light and dark adaptation are similar to those observed in visual photoreceptors; in Phycomyces, the cell is naturally isolated and amenable to genetic approaches. Action spectra for phototropism and the related light-growth response will be measured to characterize the low and high intensity photosystems of the sporangiophore. Experiments with monochromatic and dichromatic continuous irradiation will be applied in a way that allows the determination of components of each photosystem and their interaction with components of the other photosystem. These experiments will also involve single and double pulse stimuli applied to dark adapted sporangiophores of wild type and mutants with altered photoreceptors; the experiments will detect any light-absorbing intermediates. The experiments will be recorded with time-lapse video equipment. Null action spectra for the light-growth response will be measured automatically on the Phycomyces tracking machine; the results will be compared with phototropic balance spectra to determine whether these responses both use the components of the photoreceptor system in the same way. The recently discovered dependence of dark adaptation on low level residual light will be pursued to help establish which photoreceptor mediates this cryptic sensitivity when the sporangiophore is unable to respond directly. System-identification experiments on the light-growth response will be continued on the tracking machine with sum-of-sinusoids test stimuli to measure the dynamic and nonlinear aspects of this response under conditions of wavelength, temperature, and intensity range. 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.

将在真菌中研究光感受和感觉转导 藻霉菌，与其向光性和其他蓝光有关 回应。 长期目标是了解细胞和 分子水平，光等刺激的过程 转化为细胞反应。 单细胞孢子梗 藻霉菌作为初级受体细胞的模型系统。 这 光强度和动力学的绝对操作范围为 10-10:1 光适应和暗适应与视觉中观察到的相似 光感受器；在须霉菌中，细胞是自然分离且易于接受的 遗传方法。 向光性及相关的作用光谱 将测量光生长响应来表征低和高 孢子梗的强度光系统。 实验与 单色和二色连续照射将应用于 允许确定每个光系统的组成部分的方式 它们与其他光系统组件的相互作用。 这些 实验还将涉及施加单脉冲和双脉冲刺激 野生型和突变体的暗适应孢子梗 光感受器；实验将检测任何光吸收 中间体。 实验将用延时视频记录 设备。 光生长响应的零作用光谱将是 在须霉菌追踪机上自动测量；结果将 与向光性平衡光谱进行比较以确定这些是否 反应都使用相同的感光系统组件 方式。 最近发现暗适应对低水平的依赖 将追踪残余光以帮助确定哪个光感受器 当孢子梗无法介导这种神秘的敏感性时 直接回应。 光生长系统识别实验 响应将在跟踪机上继续使用正弦曲线和 测试刺激来测量该响应的动态和非线性方面 在波长、温度和强度范围的条件下。 这些 实验将涉及野生型和突变株，并且将 用光传感动力学分析模型进行解释 转导链。