Chung H M, Shea C, Fields S, Taub R N, Van der Ploeg L H, Tse D B
Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, New York, NY 10032.
EMBO J. 1990 Aug;9(8):2611-9. doi: 10.1002/j.1460-2075.1990.tb07443.x.
We studied the spatial organization of chromatin in the interphase G1, S and G2 nucleus of the protozoan Trypanosoma brucei, applying in situ hybridization with conventional fluorescence and confocal scanning optical microscopy. The majority of the trypanosome telomere GGGTTA repeats from different chromosomes were found clustered together, either extending in a network through the nuclear interior or localized at the nuclear periphery. The population of one hundred mini-chromosomes was often asymmetrically located: either clustered in a narrow band in close association with the nuclear envelope or distributed into several clusters that segregated into roughly one half of the nucleus. The nuclear organization may undergo modifications during the cell cycle and development. We conclude that non-random spatial positioning of DNA exists in the nucleus of this protozoan. Finding a high level of structural organization in the interphase nucleus of T.brucei is an important first step towards understanding chromosome structure and functioning and its role in the control of gene expression.
我们运用传统荧光和共聚焦扫描光学显微镜原位杂交技术，研究了原生动物布氏锥虫间期G1、S和G2细胞核中染色质的空间组织。发现来自不同染色体的大多数锥虫端粒GGGTTA重复序列聚集在一起，要么在核内呈网络状延伸，要么位于核周边。一百个小染色体群体的定位往往不对称：要么聚集在与核膜紧密相连的窄带中，要么分布在几个簇中，这些簇大致分隔在细胞核的一半区域。细胞核组织可能在细胞周期和发育过程中发生改变。我们得出结论，这种原生动物的细胞核中存在DNA的非随机空间定位。在布氏锥虫间期细胞核中发现高水平的结构组织，是理解染色体结构与功能及其在基因表达调控中作用的重要第一步。
