Lazareva Elena M, Polyakov Vladimir Y, Chentsov Yuri S, Smirnova Elena A
Department of Cell Biology and Histology, Biology Faculty, Moscow State University, 119992, Moscow, Russia.
Cell Biol Int. 2003;27(8):633-46. doi: 10.1016/s1065-6995(03)00120-3.
We have investigated the appearance and reorganization of tubulin-containing arrays induced by colchicine in the root meristem of wheat Triticum aestivum, using immunostaining and electron microscopy. Colchicine caused depolymerization of microtubules and formation of tubulin cortical strands composed of filamentous material only in C-mitotic cells. After prolonged exposure to the drug, both interphase and C-mitotic cells acquired needle-type bundles, arranged as different crystalloids and/or macrotubules. The unmodified tyrosinated form of alpha-tubulin was detected within microtubules in control cells, but was not found within cortical strands. It was identified, however, within needle-type bundles. The modified acetylated form of alpha-tubulin, which was absent in control cells, was detected within needle-type bundles. Thus, cortical strands were transitory arrays, transformed into needle-type bundles during prolonged exposure to colchicine. Cortical strands appeared in a cell cycle-dependent manner, whereas needle-type bundles were cell cycle stable arrays. The diverse morphological organization, intracellular distribution and stability of tubulin-containing arrays may be associated with heterogeneity of alpha-tubulin isoforms. We assume that non-microtubular arrays substitute for microtubules in conditions where normal tubulin polymerization is inhibited.
我们利用免疫染色和电子显微镜技术，研究了秋水仙碱诱导的小麦（Triticum aestivum）根分生组织中含微管蛋白阵列的出现和重组情况。秋水仙碱仅在C有丝分裂细胞中导致微管解聚，并形成仅由丝状物质组成的微管蛋白皮质丝。长时间暴露于该药物后，间期细胞和C有丝分裂细胞均获得了针状束，排列成不同的晶体和/或大微管。在对照细胞的微管中检测到未修饰的酪氨酸化形式的α-微管蛋白，但在皮质丝中未发现。然而，在针状束中发现了它。在对照细胞中不存在的修饰的乙酰化形式的α-微管蛋白，在针状束中被检测到。因此，皮质丝是短暂的阵列，在长时间暴露于秋水仙碱期间转变为针状束。皮质丝以细胞周期依赖性方式出现，而针状束是细胞周期稳定的阵列。含微管蛋白阵列的不同形态组织、细胞内分布和稳定性可能与α-微管蛋白同工型的异质性有关。我们假设在正常微管蛋白聚合受到抑制的情况下，非微管阵列替代了微管。
