MEMBRANE DISTRIBUTION IN DIVIDING ENDOSPERM CELLS OF HAEMANTHUS
MEMBRANE DISTRIBUTION IN DIVIDING ENDOSPERM CELLS OF HAEMANTHUS
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DOI：
10.1083/jcb.94.3.637
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发表时间：
1982-01-01
影响因子：
7.8
通讯作者：
DOYLE, BG
中科院分区：
文献类型：
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作者：
JACKSON, WT;DOYLE, BG
用 OsO4-亚铁氰化钾后固定后，对 Haemanthus 的无细胞壁分裂胚乳细胞的膜进行了检查。中期细胞膜的保存和染色变化很大。即使是相邻的细胞也经常表现出不同程度的膜保存。该方法揭示了 Haemanthus 有丝分裂纺锤体中比之前使用戊二醛-Os 固定所揭示的更广泛的膜系统。在前期，膜系统与着丝粒束相关联。到中期，膜构成着丝粒束的显着特征，终止于着丝粒附近。通过会聚微管和相关膜来识别的微极分布在横向延伸穿过细胞极区的区域中。微管似乎终止于小极，而膜系统的方向通常垂直于纺锤体轴线，并在远端与无定形电子致密材料、螺旋多聚核糖体和细胞器的区域接合。这种广泛的膜系统（如果有的话）在染色体运动中的作用尚不清楚。其分布与这些细胞中期富钙膜和动粒纤维的分布一致。这些膜可能会产生 Ca 结构域，而 Ca 结构域反过来又可能在染色体运动中发挥调节作用。
Membranes in cell-wall-free dividing endosperm cells of Haemanthus were examined after postfixation with OsO4-potassium ferrocyanide. Preservation and staining of membranes in metaphase cells was highly variable. Even adjacent cells often showed different degrees of preservation of membrane. This method reveals a much more extensive membrane system in the mitotic spindle of Haemanthus than has been revealed previously using glutaraldehyde-Os fixation. At prometaphase, a system of membranes becomes associated with the kinetochore bundles. By metaphase, membranes constitute a prominent feature of kinetchore bundles, terminating near the kinetochores. Minipoles, identified by converging microtubules and associated membranes, are distributed in a zone extending laterally across the polar regions of the cell. The microtubules appear to terminate at the minipoles, whereas the membrane system becomes oriented generally perpendicular to the spindle axis and interfaces distally with a region of amorphous electrondense material, helical polyribosomes and cell organelles. The role of this extensive membrane system, if any, in chromosome movement is unknown. Its distribution is coincident with the distribution of Ca-rich membranes and kinetochore fibers at metaphase in these cells. These membranes may function in creating Ca domains that, in turn, may play a regulatory role in chromosome movement.