ABSTRACT

To better understand the dynamics of the coralline algal thallus surface, scanning and transmission electron microscopy were used to examine the structure and development of epithallial cells and trichocyte initials in three species of Amphiroa. Epithallial cells possessed several distinctive organic wall layers. A densely fibrillar, moderately electron-dense layer completely surrounded each epithallial cell. Inward of this layer on the distal cell face, irregular deposits of wall material projected into the cell lumen. Outward on the distal cell surface, an electron-dense layer tapered from a central conical projection. This cone of distal wall material originated before the epithallial cell that ultimately bore it, having been deposited by an initial cell to sever its connection with a senescing epithallial cell in advance of epithallial cell replacement. This wall feature provided an indication of epithallial cell regeneration. Trichocyte initials were present beneath the layer of epithallial cells. The calcified sidewall of the epithallial cell overlaying the trichocyte chamber contained a channel that terminated in a pore through which the shaft of a trichocyte could pass. Lateral to the trichocyte initial, uncalcified walls still bearing pit plugs once shared by the initial cell and multiple generations of lost and regenerated trichocytes were compressed against the side of the trichocyte chamber. A single section of one trichocyte chamber showed 17 remnant pit plugs, indicating a high frequency of trichocyte turnover. Comparisons drawn from the published literature suggest that trichocyte development has the potential to serve as a source of systematic characters for coralline algae.

摘要

为了更好地了解珊瑚藻藻体表面的动力学，使用扫描和透射电子显微镜检查了3种安非他命的上皮细胞的结构和发育以及毛细胞的缩写。上皮细胞具有几个独特的有机壁层。密集的原纤维，中等电子密度层完全包围了每个上皮细胞。在远端细胞表面上该层的内侧，壁材料的不规则沉积物投射到细胞腔中。在远端细胞表面的外部，有一个电子密集层，从中央圆锥形突起逐渐变细。该远端壁材料的锥体起源于最终使之上皮的上皮细胞之前，已经由初始细胞沉积以在上皮细胞置换之前切断其与敏感的上皮细胞的连接。该壁特征提供了上皮细胞再生的指示。上皮细胞层下方存在着单核细胞的缩写。覆盖在毛发细胞腔上的上皮细胞的钙化侧壁包含一条通道，该通道终止于毛发细胞的轴可穿过的孔中。在单毛细胞的外侧，未钙化的壁一旦被初始细胞所共享，仍带有凹坑塞，并且失去的和再生的多毛细胞的世代被压靠在单毛细胞腔室的侧面。一个单毛细胞腔的单个部分显示出17个残留的凹坑塞，表明单毛细胞周转的频率很高。从已发表的文献中得出的比较结果表明，毛发细胞的发育有潜力成为珊瑚藻系统性状的来源。未钙化的壁一旦被最初的细胞所共享，仍然带有凹坑塞，并且失去的和再生的毛细胞的多代被压缩在毛细胞腔的侧面。一个单毛细胞腔的单个部分显示出17个残留的凹坑塞，表明单毛细胞周转的频率很高。从已发表的文献中得出的比较结果表明，毛发细胞的发育有潜力成为珊瑚藻系统性状的来源。未钙化的壁一旦被最初的细胞所共享，仍然带有凹坑塞，并且失去的和再生的毛细胞的多代被压缩在毛细胞腔的侧面。一个单毛细胞腔的单个部分显示出17个残留的凹坑塞，表明单毛细胞周转的频率很高。从已发表的文献中得出的比较结果表明，毛发细胞的发育有潜力成为珊瑚藻系统性状的来源。