家鸽光依赖的磁感机制研究

Several species are known to use the Earth's magnetic field for orientation and navigation. It is demonstrated that the ultraviolet-A/blue-light photoreceptor cryptochrome (Cry) is involved in as a magnetic compass. Many studies have found that in most cases the magnetic effect is ascribed to Ca2+ ions. However, the mechanism by which cryptochrome transmits the magnetic signal to biochemical signals and finally to electric signals is not known. In this study we will use the animal model homing pigeons, Columba livia, a species using the magnetic field for compass orientation，to investigate the physiological mechanism underneath. We will screen the differential interacting-partners of cryptochrome using the yeast two-hybrid system in the absence and presence of applied magnetic fields. Meanwhile, electrophysiological methods will be used to screen the Ca2+ channels of the ultraviolet/violet (UV/V) cones which are involved in this magnetic sensitivity. Furthermore, Gene-knockout lines and commercially available fly stocks will be used to perform behavioural assay to verify the proteins and ion channels involved in the magnetosensitivity pathway. This study wil provide a direct evidence for understanding cryptochrome dependent animal magnetosensitivity and strengthen the theoretical basis of bionic navigation material using the Earth's magnetic field.

多种动物可利用地磁场信息进行定位和导航。研究表明，蓝光/A区紫外光受体-隐花色素作为磁罗盘参与了这一过程。大部分情况下，磁场生物效应归因于对胞内Ca2+的影响。隐花色素感知磁场信号后，通过何种生化途径转化为电生理信号目前仍是空白。本项目拟以典型地磁导航生物-家鸽为模型，以隐花色素为诱饵，通过酵母双杂交筛选不同磁场环境的差异相互作用蛋白，并通过其他生物化学手段验证这种相互作用，同时利用膜片钳、钙成像等手段研究家鸽视网膜上的视锥细胞在不同磁场条件下的电生理学特性，以求发现参与磁感过程的相关离子通道。最后，利用果蝇遗传学手段或商业获取相关果蝇品系针对筛选到的磁感通路蛋白或离子通道，行为学实验验证其功能。该课题的开展有助于加深对动物磁感的理解，并可为发展仿生磁探测技术提供理论依据。

多种动物可利用地磁场信息进行定位和导航。研究表明，蓝光/A区紫外光受体—隐花色素作为磁罗盘参与了这一过程。本项目以典型地磁导航生物—家鸽为模型，首次克隆获得其隐花色素（ClCRY1）基因，利用昆虫细胞表达系统完成了活性蛋白的异源表达及批量获取；通过高通量酵母双杂交技术筛选出与ClCRY1相互作用的7个候选下游受体蛋白，利用深度测序数据对鸽子左右眼差异表达进行了磁信号通路分析；利用瞬态荧光光谱技术对活性蛋白测试与表征，通过对ClCRY1蛋白结构预测与动力学分析；建立动物磁感机理模型；初步验证了仿生地磁导航的原理与技术可行性。