大肠杆菌细胞释放细胞质时伴随的有限DNA压缩损失。

A limited loss of DNA compaction accompanying the release of cytoplasm from cells of Escherichia coli.

作者信息

Murphy L D, Zimmerman S B

机构信息

Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892-0560, USA.

出版信息

J Struct Biol. 2001 Jan;133(1):75-86. doi: 10.1006/jsbi.2001.4331.

DOI:10.1006/jsbi.2001.4331

PMID:11356066

Abstract

The DNA of bacteria is compacted into nucleoids. We have lysed cells of Escherichia coli under conditions in which the cell envelope is retained. The extent of DNA compaction was determined by light microscopy, comparing DAPI fluorescence and phase contrast images. The release of cytoplasm upon lysis allowed the nucleoidal DNA to expand to fill the residual cell boundaries, supporting the role of cytoplasmic crowding in nucleoid compaction. The addition of polylysine allowed lysis with retention of DNA compaction. Furthermore, chloramphenicol treatment of cells resulted in nucleoids which were more resistant to decompaction upon lysis.

摘要

细菌的DNA被压缩成类核。我们在保留细胞包膜的条件下裂解了大肠杆菌细胞。通过比较DAPI荧光和相差图像，利用光学显微镜确定了DNA压缩程度。裂解时细胞质的释放使类核DNA得以扩展以填充残留的细胞边界，这支持了细胞质拥挤在类核压缩中的作用。添加聚赖氨酸可在保留DNA压缩的情况下实现裂解。此外，用氯霉素处理细胞会导致类核在裂解时对解压缩更具抗性。