Neuronal and genetic basis of photosensory behavior in C. elegans

我们研究的长期目标是了解动物如何感知环境线索并作出反应。的 目前的建议侧重于光的感觉，这是一种对动物生命至关重要的感觉方式。检测到光 视网膜中的感光细胞，在那里它们调节图像形成视觉。此外，感光细胞， 特别是那些眼外感光细胞，介导非成像功能如趋光性， 昼夜节律、瞳孔收缩和磁定向。虽然图像形成的愿景一直是 广泛的特点，相对知之甚少的机制，非成像功能 光感受器细胞。线虫C.秀丽线虫是一种流行的遗传模式生物，用于研究感觉器官， 诸如化学感觉（例如嗅觉和味觉）和机械感觉（例如触觉 和本体感受）。然而，C.人们认为，优雅的人缺乏光感，因为他们生活在黑暗中 （土）也没有眼睛。有趣的是，我们最近证明了这些没有眼睛的动物， 令人惊讶的是，拥有光的感觉，并从事感光行为（趋光性），使他们能够 避免致命剂量的光，还提供了一种将它们保留在黑暗环境中的潜在机制。 有趣的是，类似的现象也存在于其他生物体中，例如果蝇幼虫，它需要 眼外感光细胞。在这里，我们建议阐明光感觉的机制， C.优雅我们将识别所有趋光性所需的感光细胞，确定信号传导， 光感受器细胞中的机制，并识别光感受器蛋白。我们将采取多学科 方法结合遗传学，行为分析，药理学，生物化学和电生理学。的 提出的研究将提供新的见解的非成像功能的机制， 哺乳动物的感光细胞。

The long term goal of our research is to understand how animals sense and react to environmental cues. The current proposal focuses on the sense of light, a sensory modality critical for animal life. Light is detected by photoreceptor cells in the retina where they mediate image-forming vision. In addition, photoreceptor cells, particularly those extra-ocular photoreceptor cells, mediate non-image-forming functions such as phototaxis, circadian rhythms, pupil constriction, and magnetic orientation. While the image-forming vision has been extensively characterized, relatively little is known about the mechanisms of the non-image-forming functions of photoreceptor cells. The nematode C. elegans is a popular genetic model organism for the study of sensory transduction such as chemosensation (e.g. olfaction and taste) and mechanosensation (e.g. touch sensation and proprioception). However, C. elegans were believed to lack the sense of light, as they live in darkness (soil) and also do not have eyes. Interestingly, we have recently demonstrated that these eyeless animals, surprisingly, possess the sense of light and engage in photosensory behavior (phototaxis) that allows them to avoid lethal doses of light and also provides a potential mechanism for retaining them in dark environments. Intriguingly, a similar phenomenon also exists in other organisms, such as Drosophila larva, which requires extra-ocular photoreceptor cells. Here we propose to elucidate the mechanisms underlying photosensation in C. elegans. We will identify all the photoreceptor cells required for phototaxis, determine the signaling mechanisms in photoreceptor cells, and identify the photoreceptor protein. We will take a multidisciplinary approach combining genetics, behavioral analysis, pharmacology, biochemistry, and electrophysiology. The proposed study will provide novel insights into the mechanisms of the non-image-forming functions of photoreceptor cells in mammals.