Nakajima Yoko
Department of Biology, Keio University, Yokohama 223, Japan.
Dev Growth Differ. 1986 May;28(3):243-249. doi: 10.1111/j.1440-169X.1986.00243.x.
Removal of the hyaline layer from sea urchin embryos at the pluteus stage discloses a densely ciliated region in the preoral area of the ectodermal epithelium. In four-armed plutei, this ciliary path is located between the anterolateral arms and in eight-armed plutei it becomes surrounded by preoral and anterolateral arms. The area of the patch and the number of cilia increase with age. This patch is covered by cilia of unusual morphology and orientation. There are more than two cilia per cell which are coiled together several times around a small cone at the apical end of the cell. These coiled cilia run parallel to the surface of the cell but do not extend beyond the hyaline layer. The ciliary axoneme consists of a "9+2" microtubular structure, but no outer or inner dynein arms are observed. Although the cells with coiled cilia are present in a cluster constituting a part of the epithelium, they have axons that project from their basal (inner) ends. The structural characteistics of the ciliary patch suggest that it possesses a sensory function.
去除海胆胚胎长腕幼虫期的透明层后，可发现外胚层上皮口前区域有一个密布纤毛的区域。在四腕长腕幼虫中，这条纤毛路径位于前侧臂之间，而在八腕长腕幼虫中，它被口前臂和前侧臂包围。纤毛斑的面积和纤毛数量随年龄增长而增加。这个纤毛斑被形态和方向异常的纤毛覆盖。每个细胞有两根以上的纤毛，它们在细胞顶端围绕一个小锥体缠绕多次。这些缠绕的纤毛与细胞表面平行，但不延伸到透明层之外。纤毛轴丝由“9+2”微管结构组成，但未观察到外动力蛋白臂或内动力蛋白臂。尽管有缠绕纤毛的细胞聚集成簇，构成上皮的一部分，但它们有从基部（内侧）末端伸出的轴突。纤毛斑的结构特征表明它具有感觉功能。
