The role of targeted secretion in the establishment of cell polarity and the orientation of the division plane in Fucus zygotes.
The role of targeted secretion in the establishment of cell polarity and the orientation of the division plane in Fucus zygotes.
复制标题
定向分泌在墨角藻合子细胞极性建立和分裂平面方向中的作用。
作者：
S. Shaw;R. Quatrano
在这项研究中，我们研究了极性分泌的作用以及由此产生的细胞壁不对称性在墨角藻受精卵建立极性中的作用。我们利用布雷菲德菌素-A 选择性地阻断高尔基体来源的物质分泌到细胞壁中，通过硫酸岩藻多糖的甲苯胺蓝 O 染色进行测定。我们表明，高尔基体衍生物质的极性分泌靶向受精卵的皮质位点，该位点通过肌动蛋白丝和二氢吡啶受体的定位来识别。高尔基体来源的物质沉积到该目标位点的细胞壁中与极轴固定在时间上一致并且是必需的。我们提出，高尔基体来源的物质局部分泌到细胞壁中，将目标位点转变为极性生长的固定位点。我们还发现，高尔基体来源物质在固定位点的极性分泌对于假根的生长和分化以及细胞分裂第一平面的正确定位至关重要。我们认为细胞壁中产生的不对称性可以作为底层皮层启动这些极性事件的位置信息。我们的数据支持这样的假设：胚胎中的细胞壁因子先前被证明负责诱导假根细胞分化，与极轴固定同时沉积并负责极轴固定。此外，极性生长的模式可归因于固定位点的位置信号，并且似乎与第一细胞分裂平面的方向无关。因此，合子细胞极性的建立，而不是第一分裂面的位置，对于墨角藻初始胚胎模式的形成至关重要。
In this study, we investigate the role of polar secretion and the resulting asymmetry in the cell wall in establishing polarity in Fucus zygotes. We have utilized brefeldin-A to selectively interrupt secretion of Golgi-derived material into the cell wall as assayed by toluidine blue O staining of sulfated fucoidin. We show that the polar secretion of Golgi-derived material is targeted to a cortical site of the zygote identified by the localization of actin filaments and dihydropyridine receptors. The deposition of Golgi-derived material into the cell wall at this target site is temporally coincident with and required for polar axis fixation. We propose that local secretion of Golgi-derived material into the cell wall transforms the target site into the fixed site of polar growth. We also found that polar secretion of Golgi-derived material at the fixed site is essential for growth and differentiation of the rhizoid, as well as for the proper positioning of the first plane of cell division. We propose that the resulting asymmetry in the cell wall serves as positional information for the underlying cortex to initiate these polar events. Our data supports the hypothesis that cell wall factors in embryos, previously shown to be responsible for induction of rhizoid cell differentiation, are deposited simultaneously with and are responsible for polar axis fixation. Furthermore, the pattern of polar growth is attributable to a positional signal at the fixed site and appears to be independent of the orientation of the first cell division plane. Thus, the establishment of zygotic cell polarity and not the position of the first division plane, is critical for the formation of the initial embryonic pattern in Fucus.
海胆（Lytechinus variegatus）间充质囊胚植物板的命运图。
DOI：
10.1242/dev.122.1.253
发表时间：
1996
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Ruffins,SW;Ettensohn,CA
通讯作者：
Ettensohn,CA