在粗壮真核生物大核发育过程中检测消除性DNA的环状形式。

Detection of circular forms of eliminated DNA during macronuclear development in E. crassus.

作者信息

Tausta S L, Klobutcher L A

机构信息

Department of Biochemistry, University of Connecticut Health Center, Farmington 06032.

出版信息

Cell. 1989 Dec 22;59(6):1019-26. doi: 10.1016/0092-8674(89)90758-7.

DOI:10.1016/0092-8674(89)90758-7

PMID:2598258

Abstract

Following their sexual cycle, hypotrichous ciliated protozoa transform a copy of a chromosomal micronucleus into a macronucleus containing small, linear DNA molecules. A frequent event during macronuclear development is the removal of short segments of DNA (internal eliminated sequences: IESs) by a process equivalent to DNA breakage and rejoining. In this study we used a polymerase chain reaction procedure to demonstrate that free circular forms of IESs are present in cells undergoing macronuclear development. Sequencing of the junctions of the free circular IESs suggests that they share 12 nucleotides with the macronuclear DNA molecules that are generated following IES removal. The results provide evidence that IESs are removed by an active DNA breakage and rejoining process, which may involve staggered cuts in the substrate DNA.

摘要

在其有性周期之后，腹毛目纤毛虫将染色体微核的一个拷贝转化为含有小的线性DNA分子的大核。大核发育过程中的一个常见事件是通过一个等同于DNA断裂和重新连接的过程去除短的DNA片段（内部消除序列：IESs）。在本研究中，我们使用聚合酶链反应程序来证明IESs的游离环状形式存在于正在进行大核发育的细胞中。对游离环状IESs连接处的测序表明，它们与IES去除后产生的大核DNA分子共享12个核苷酸。结果提供了证据，表明IESs是通过主动的DNA断裂和重新连接过程被去除的，这可能涉及底物DNA中的交错切割。