The microtubule aster formation and its role in nuclear envelope assembly around the sperm chromatin in Xenopus egg extracts  

作　　者：YANG Ning CHEN Zhongcai LU Ping ZHANG Chuanmao ZHAI Zhonghe TANG Xiaowei 

机构地区：[1]Institute of High Energy Physics,Chinese Accademy of Sciences,Beij ing 100039,China [2]Department of Cell Biology and Genetics,Peking University,Beijing 100871,China [3]National Laboratory of Biomembrane and Membrane Biotechnology,College of Life Sciences,Peking University,Beijing 100871,China [4]Department of Physics,Zhejiang University,Hangzhou 310027,China

出　　处：《Chinese Science Bulletin》2003年第18期1912-1918,共7页

摘　　要：Nuclear envelope is a dynamic structure in the cell cycle. At the beginning of mitosis, nuclear envelope breaks down and its components disperse into the cytoplasm. At the end of mitosis, nuclear envelope reassembles using the dispersed components. Searching for the mechanisms of the nuclear disassembly and reassembly has for a long time been one of the key projects for cell biologists. In this report we show that microtubules take a role in the nuclear envelope assembly around the sperm chromatin in Xenopus egg ex-tracts. Microtubule cytoskeleton has been demonstrated to take roles in the transport of intracellular membranes such as Golgi and ER vesicles. We found that the nuclear envelope assembly needs functional microtubules. At the beginning of the nuclear assembly, microtubules nucleated to form a microtubule aster around the centrosome at the base of the sperm head. Using the microtubule drug colchicine to dis-rupt the microtubule nucleation, nuclear envelope reassem-bly was seriously inhibited. If the microtubules were stabi-lized by taxol, another microtubule drug, the nuclear enve-lope reassembly was also interfered, although a significantly large aster formed around the chromatin. Based on these observations, we propose that microtubules play an impor-tant role in the nuclear envelope reassembly maybe by transporting the nuclear envelope precursors to the chroma-tin surfaces.Nuclear envelope is a dynamic structure in the cell cycle. At the beginning of mitosis, nuclear envelope breaks down and its components disperse into the cytoplasm. At the end of mitosis, nuclear envelope reassembles using the dispersed components. Searching for the mechanisms of the nuclear disassembly and reassembly has for a long time been one of the key projects for cell biologists. In this report we show that microtubules take a role in the nuclear envelope assembly around the sperm chromatin inXenopus egg extracts. Microtubule cytoskeleton has been demonstrated to take roles in the transport of intracellular membranes such as Golgi and ER vesicles. We found that the nuclear envelope assembly needs functional microtubules. At the beginning of the nuclear assembly, microtubules nucleated to form a microtubule aster around the centrosome at the base of the sperm head. Using the microtubule drug colchicine to disrupt the microtubule nucleation, nuclear envelope reassembly was seriously inhibited. If the microtubules were stabilized by taxol, another microtubule drug, the nuclear envelope reassembly was also interfered, although a significantly large aster formed around the chromatin. Based on these observations, we propose that microtubules play an important role in the nuclear envelope reassembly maybe by transporting the nuclear envelope precursors to the chromatin surfaces.

关 键 词：nuclear reassembly MICROTUBULE COLCHICINE TAXOL XENOPUS EGG extracts. 

分 类 号：Q25[生物学—细胞生物学]