Istituto di Biofisica, CNR, via Moruzzi 1, 56124 Pisa, Italy.
Integr Biol (Camb). 2012 Jan;4(1):22-36. doi: 10.1039/c1ib00115a. Epub 2011 Nov 14.
The ability to sense light can be considered the most fundamental and presumably the most ancient property of visual systems. This ability is the basis of phototaxis, one of the most striking behavioral responses of motile photosynthetic microorganisms (i.e. microalgae) to light stimuli, which allows them to move toward or away directional light. In order to fully exploit the information content of light (intensity, direction, distribution) microorganisms need proper perceiving devices, termed photoreceptors, which must act as sensors, to perceive wavelength and direction of light, as transducers, to convert the light signal into chemical and/or electrical information, but also as amplifiers and eventually as transmitters. This review describes the universal structural, behavioral and physiological features necessary for the proper functioning of these devices in algae, and how these features have been investigated by means of different analytical techniques such as for example microspectroscopy, digital fluorescence microscopy, two photons FLIM. The insight of the photoreceptive response mechanism is explained using the unicellular alga Euglena gracilis, in which the different structural, behavioral and physiological features combine to achieve a concerted, efficient response to light stimuli.
感光能力可以被认为是视觉系统最基本和最古老的特性。这种能力是趋光性的基础，趋光性是运动光合作用微生物（即微藻）对光刺激的最显著行为反应之一，使它们能够朝着或远离定向光移动。为了充分利用光的信息含量（强度、方向、分布），微生物需要适当的感知设备，称为光感受器，这些设备必须作为传感器，感知光的波长和方向，作为换能器，将光信号转换为化学和/或电信息，而且还要作为放大器，最终作为发射器。本综述描述了这些设备在藻类中正常运行所需的通用结构、行为和生理特征，以及如何通过不同的分析技术（例如微光谱学、数字荧光显微镜、双光子 FLIM）来研究这些特征。使用单细胞藻类眼虫来解释光感受反应机制，其中不同的结构、行为和生理特征结合在一起，对光刺激做出协调、有效的反应。
