Temporal and spatial coordination of chromosome movement, spindle formation, and nuclear envelope breakdown during prometaphase in Drosophila melanogaster embryos.
Temporal and spatial coordination of chromosome movement, spindle formation, and nuclear envelope breakdown during prometaphase in Drosophila melanogaster embryos.
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DOI：
10.1083/jcb.111.6.2815
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发表时间：
1990-12
影响因子：
7.8
通讯作者：
Sedat, J W
中科院分区：
文献类型：
--
作者：
Hiraoka, Y;Agard, D A;Sedat, J W
用三维光学切片显微镜分析了黑腹果蝇合体胚泡胚二倍体染色体组织、微管排列和核膜状态从前期向中期转变的时空动态。在活胚胎中记录的时间推移的三维数据显示，前中期染色体的聚集(染色体移动形成中期板的过程)以波的形式发生，从靠近胚胎表面的核的顶部开始，通过核一直到底部。时间推移分析通过对固定胚胎的高分辨率分析而得到加强，在这种分析中，可以明确地追踪单个染色体的三维路径。在早期，着丝粒聚集在核的顶部，而端粒位于核的底部或朝向胚胎内部。这种垂直于胚胎表面的着丝粒-端粒极化取向在早中期染色体聚集过程中被保留下来。相应地，核膜的破裂开始于核的顶部，有丝分裂纺锤体形成于核膜部分破裂的位置。我们的观察提供了一个例子，其中核结构在空间上被组织起来，它们的功能在三维上被局部和协调地控制。
The spatial and temporal dynamics of diploid chromosome organization, microtubule arrangement, and the state of the nuclear envelope have been analyzed in syncytial blastoderm embryos of Drosophila melanogaster during the transition from prophase to metaphase, by three- dimensional optical sectioning microscopy. Time-lapse, three- dimensional data recorded in living embryos revealed that congression of chromosomes (the process whereby chromosomes move to form the metaphase plate) at prometaphase occurs as a wave, starting at the top of the nucleus near the embryo surface and proceeding through the nucleus to the bottom. The time-lapse analysis was augmented by a high- resolution analysis of fixed embryos where it was possible to unambiguously trace the three-dimensional paths of individual chromosomes. In prophase, the centromeres were found to be clustered at the top of the nucleus while the telomeres were situated at the bottom of the nucleus or towards the embryo interior. This polarized centromere-telomere orientation, perpendicular to the embryo surface, was preserved during the process of prometaphase chromosome congression. Correspondingly, breakdown of the nuclear envelope started at the top of the nucleus with the mitotic spindle being formed at the positions of the partial breakdown of the nuclear envelope. Our observation provide an example in which nuclear structures are spatially organized and their functions are locally and coordinately controlled in three dimensions.