EFFECT OF LATRUNCULIN B AND BREFELDIN A ON CYTOKINESIS IN THE BROWN ALGA SCYTOSIPHON LOMENTARIA (SCYTOSIPHONALES, PHAEOPHYCEAE)
EFFECT OF LATRUNCULIN B AND BREFELDIN A ON CYTOKINESIS IN THE BROWN ALGA SCYTOSIPHON LOMENTARIA (SCYTOSIPHONALES, PHAEOPHYCEAE)
复制标题
DOI：
10.1111/j.1529-8817.2009.00655.x
复制
发表时间：
2009-04-01
影响因子：
2.9
通讯作者：
Motomura, Taizo
中科院分区：
文献类型：
--
作者：
Nagasato, Chikako;Motomura, Taizo
在褐藻的合子中。细胞质分裂通过膜囊的生长进行，这些膜囊是由高尔基囊泡和积聚在未来细胞动力学平面上的扁平池融合形成的。据报道，拉温库林B解聚肌动蛋白丝并不抑制有丝分裂。然而，这种分子阻止肌动蛋白板的形成，肌动蛋白板出现在细胞分裂前和分裂过程中来自每个中心体的混合微管区域。在本研究中，用电镜观察受精卵经拉runculin B处理后的情况，发现该试剂明显抑制扁平池的形成。高尔基囊泡聚集在两个子核之间的中间区域，并在那里与质膜融合。结果，质膜以复杂的方式内陷到细胞质中。然而，这些内陷的质膜从未产生连续的隔膜。用brefeldin A处理受精卵的超微结构也进行了检测，brefeldin A可以阻止高尔基蛋白介导的分泌。在未来的细胞动力学平面上出现扁平池，形成新的细胞隔膜。然而，隔断膜变厚了，因为它被无定形材料填充，而不是正常的刚性纤维材料。这些结果表明，肌动蛋白参与扁平池的形成，这是完成新的细胞分隔膜所必需的，高尔基囊泡可能在细胞壁物质的沉积中起重要作用。
In zygotes of the brown alga Scytosiphon lomentaria (Lyngb.) Link, cytokinesis proceeds by growth of membranous sacs, which are formed by fusion of Golgi vesicles and flat cisternae accumulated at the future cytokinetic plane. It has been reported that depolymerization of actin filaments by latrunculin B does not inhibit mitosis. However, this molecule prevents the formation of the actin plate, which appears at the region of intermingled microtubules from each centrosome just before and during cytokinesis. In this study, zygotes treated with latrunculin B were observed using EM. Remarkably, this reagent inhibited the formation of flat cisternae. Golgi vesicles gathered around the midzone between the two daughter nuclei and fused with the plasma membrane there. As a result, the plasma membrane invaginated, in a complicated manner, into the cytoplasm. However, these invaginations of the plasma membrane never produced a continuous partition membrane. The ultrastructure of zygotes treated with brefeldin A, which prevents Golgi-mediated secretion, was also examined. Flat cisternae appeared at the future cytokinetic plane, and a new cell partition membrane was formed. However, the partition membrane became thick, because it was filled with amorphous material rather than the normal rigid fibrous material. These results suggested that actin is involved in the formation of flat cisternae, where it is necessary for completion of the new cell partition membrane, and that Golgi vesicles may play an important role in the deposition of cell wall material.