An Iron-Rich Organelle in the Cuticular Plate of Avian Hair Cells
An Iron-Rich Organelle in the Cuticular Plate of Avian Hair Cells
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DOI：
10.1016/j.cub.2013.04.025
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发表时间：
2013-05-20
期刊：
影响因子：
9.2
通讯作者：
Keays, David Anthony
中科院分区：
文献类型：
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作者：
Lauwers, Mattias;Pichler, Paul;Keays, David Anthony
毛细胞存在于脊椎动物内耳的特化上皮细胞中，介导声音、运动和重力的检测。将这些刺激转换成神经冲动需要静纤毛的偏转，静纤毛由富含肌动蛋白的表皮板稳定。最近的电生理学研究表明前庭系统与鸽子的磁感觉有关[1]。在这里，我们报告发现一个单一的富含铁的细胞器，居住在表皮板的耳蜗和前庭毛细胞的鸽子。结合元素分析的透射电子显微镜显示，该结构由铁蛋白样颗粒组成，直径约为300-600 nm，是球形的，并且在某些情况下是膜结合的和/或组织成次晶阵列。这种细胞器存在于多种鸟类的毛细胞中，但不在啮齿动物或人类中。这种结构可能起（1）多余铁的储存，（2）静纤毛的稳定剂，或（3）磁检测的中介体的作用。鉴于特定的亚细胞位置，元素组成，和进化的保守性，我们建议，这种结构是一个不可分割的组成部分，在鸟类的感觉器官。
Hair cells reside in specialized epithelia in the inner ear of vertebrates, mediating the detection of sound, motion, and gravity. The transduction of these stimuli into a neuronal impulse requires the deflection of stereocilia, which are stabilized by the actin-rich cuticular plate. Recent electrophysiological studies have implicated the vestibular system in pigeon magnetosensation [1]. Here we report the discovery of a single iron-rich organelle that resides in the cuticular plate of cochlear and vestibular hair cells in the pigeon. Transmission electron microscopy, coupled with elemental analysis, has shown that this structure is composed of ferritin-like granules, is approximately 300-600 nm in diameter, is spherical, and in some instances is membrane-bound and/or organized in a paracrystalline array. This organelle is found in hair cells in a wide variety of avian species, but not in rodents or in humans. This structure may function as (1) a store of excess iron, (2) a stabilizer of stereocilia, or (3) a mediator of magnetic detection. Given the specific subcellular location, elemental composition, and evolutionary conservation, we propose that this structure is an integral component of the sensory apparatus in birds.