Erickson Timothy, Biggers William Paul, Williams Kevin, Butland Shyanne E, Venuto Alexandra
Department of Biology, University of New Brunswick, Fredericton, NB E3B 5A3, Canada.
Department of Biology, East Carolina University, Greenville, NC 27858, USA.
J Dev Biol. 2023 Jun 16;11(2):28. doi: 10.3390/jdb11020028.
Sensory hair cells are the receptors for auditory, vestibular, and lateral line sensory organs in vertebrates. These cells are distinguished by "hair"-like projections from their apical surface collectively known as the hair bundle. Along with the staircase arrangement of the actin-filled stereocilia, the hair bundle features a single, non-motile, true cilium called the kinocilium. The kinocilium plays an important role in bundle development and the mechanics of sensory detection. To understand more about kinocilial development and structure, we performed a transcriptomic analysis of zebrafish hair cells to identify cilia-associated genes that have yet to be characterized in hair cells. In this study, we focused on three such genes-, , and -because human or mouse orthologs are either associated with sensorineural hearing loss or are located near uncharacterized deafness loci. We made transgenic fish that express fluorescently tagged versions of their proteins, demonstrating their localization to the kinocilia of zebrafish hair cells. Furthermore, we found that Ankef1a, Odf3l2a, and Saxo2 exhibit distinct localization patterns along the length of the kinocilium and within the cell body. Lastly, we have reported a novel overexpression phenotype of Saxo2. Overall, these results suggest that the hair cell kinocilium in zebrafish is regionalized along its proximal-distal axis and set the groundwork to understand more about the roles of these kinocilial proteins in hair cells.
感觉毛细胞是脊椎动物听觉、前庭和侧线感觉器官的感受器。这些细胞的特征是其顶端表面有“毛发”状突起，统称为毛束。除了充满肌动蛋白的静纤毛呈阶梯状排列外，毛束还具有一根单一的、不运动的真正纤毛，称为动纤毛。动纤毛在毛束发育和感觉检测机制中起着重要作用。为了更深入了解动纤毛的发育和结构，我们对斑马鱼毛细胞进行了转录组分析，以鉴定在毛细胞中尚未被表征的与纤毛相关的基因。在这项研究中，我们重点关注了三个这样的基因——、和——因为它们在人类或小鼠中的直系同源基因要么与感音神经性听力损失相关，要么位于未表征的耳聋基因座附近。我们制作了表达其蛋白质荧光标记版本的转基因鱼，证明了它们定位于斑马鱼毛细胞的动纤毛。此外，我们发现Ankef1a、Odf3l2a和Saxo2在动纤毛的长度和细胞体内呈现出不同的定位模式。最后，我们报道了Saxo2一种新的过表达表型。总体而言，这些结果表明斑马鱼毛细胞的动纤毛沿其近端-远端轴呈区域化分布，为进一步了解这些动纤毛蛋白在毛细胞中的作用奠定了基础。
