MICRONUCLEAR GENOME ORGANIZATION IN EUPLOTES-CRASSUS - A TRANSPOSON-LIKE ELEMENT IS REMOVED DURING MACRONUCLEAR DEVELOPMENT
MICRONUCLEAR GENOME ORGANIZATION IN EUPLOTES-CRASSUS - A TRANSPOSON-LIKE ELEMENT IS REMOVED DURING MACRONUCLEAR DEVELOPMENT
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DOI：
10.1128/mcb.9.9.3793
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发表时间：
1989-09-01
影响因子：
5.3
通讯作者：
KLOBUTCHER, LA
中科院分区：
文献类型：
--
作者：
BAIRD, SE;FINO, GM;KLOBUTCHER, LA
交配后，下毛纤毛原生动物将一组微核染色体转化为数千个短的线性DNA分子，形成大核基因组。为了研究厚腹游仆虫的微核基因组结构，我们分析了两个克隆的微核DNA片段以及来自它们的大核DNA分子。E.发现crassus显示出许多其他下毛层菌基因组的特征，包括（i）大核DNA分子前体的聚集和紧密间隔，（ii）大核前体内频繁出现内部消除序列，（iii）重叠的大核前体，（iv）在大核前体末端缺乏端粒重复序列，和（v）选择性加工微核染色体以产生多个大核DNA分子。此外，适度重复的转座子样元件，中断两个大核DNA分子的前体已被确定和表征。这种转座子样元素，指定Tec1，被证明是可重复地从一个大核的前体在独立的情节大核的发展。
After mating, hypotrichous ciliated protozoa transform a set of their micronuclear chromosomes into thousands of short, linear DNA molecules that form the macronuclear genome. To examine micronuclear genome organization in the hypotrich Euplotes crassus, we have analyzed two cloned segments of micronuclear DNA as well as the macronuclear DNA molecules that are derived from them. E. crassus was found to display a number of features characteristic of other hypotrich genomes, including (i) clustering and close spacing of the precursors of macronuclear DNA molecules, (ii) the frequent occurrence of internal eliminated sequences within macronuclear precursors, (iii) overlapping macronucleic precursors, (iv) lack of telomeric repeats at the ends of macronuclear precursors, and (v) alternative processing of the micronuclear chromosome to yield multiple macronuclear DNA molecules. In addition, moderately repetitive, transposonlike element that interrupts the precursors of two macronuclear DNA molecules has been identified and characterized. This transposonlike element, designated Tec1, is shown to be reproducibly removed from one of the macronuclear precursors during independent episodes of macronuclear development.