ELUCIDATION OF THE ENIGMA OF THE METAPHASE BAND OF CHLAMYDOMONAS-REINHARDTII
ELUCIDATION OF THE ENIGMA OF THE METAPHASE BAND OF CHLAMYDOMONAS-REINHARDTII
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DOI：
10.1007/bf01560652
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发表时间：
1990-01-01
期刊：
影响因子：
2.9
通讯作者：
ELGAMMAL, S
中科院分区：
文献类型：
--
作者：
GAFFAL, KP;ELGAMMAL, S
传统的，计算机辅助的，和形态测量分析的连续切片通过细胞在连续的有丝分裂阶段，澄清了几个方面的形态发生的所谓的“中期带”（= MB）在莱茵衣藻。与最初的解释相反，MB不是一组4个微管（= MT）。这种错误的印象是由两个父母的4元微管鞭毛根的短暂的空间关联。根的一个长的部分，这是鞭毛基部的机构和皮层细胞骨架在间期的组成部分，在有丝分裂期间持续存在。每个亲本4元根紧密耦合到一半的二等分的基体复合体，每个子细胞接收一个根。在分裂前期，分裂的基体-根复合体向核极迁移时，两个相对的根在中间弯曲。从这些弯曲的区域开始，中间的三分之一在中期变得平行排列。根缩短在后期伸长的核，发生没有任何进一步的变化之间的距离的女儿基体根复合体。在后期，观察到细胞质MT的从头组装。两个细胞内MT阵列，像皮质MT一样集中在根部，深入细胞。它们被解释为藻质体或根质体的初始分裂MT。
Conventional, computer-aided, and morphometric analysis of ultrathin serial sections through cells at consecutive stages of mitosis has clarified several aspects of the morphogenesis of the so-called "metaphase-band" (= MB) in Chlamydomonas reinhardtii. In contrast to the original interpretation, the MB is not a single set of 4 microtubules (= MTs). This erroneous impression is created by the transient spatial association of the two parental 4-membered microtubular flagellar roots. A long section of the roots, which are constituents of the flagellar basal apparatus and the cortical cytoskeleton at interphase, persists during mitosis. Each parental 4-membered root is tightly coupled to half of the bisected basal body complex, and each daughter cell receives one root. During migration of the bisected basal body-root complexes towards the nuclear poles during prophase, the two opposite roots are bent in the middle. Starting at these bent regions, the central thirds become parallelly aligned during metaphase. The roots shorten during anaphase elongation of the nucleus, which occurs without any further change in distance between the daughter basal body-root complexes. At anaphase de novo assembly of cytoplasmic MTs was observed. Two intracellular MT arrays, focussed at the roots like the cortical MTs, penetrate deeply into the cell. They are interpreted as the incipient cleavage MTs of the phycoplast, or radicoplast.