Copy Number Heterogeneity in the Virulence Plasmid of Salmonella enterica
Quantitative PCR analysis shows that the virulence plasmid of serovar Typhimurium (pSLT) is a low-copy-number plasmid, with 1-2 copies per chromosome. However, fluorescence microscopy observation of pSLT labeled with a fluorescent tag reveals cell-to-cell differences in the number of foci, which ran...
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Published in | Frontiers in microbiology Vol. 11; p. 599931 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Switzerland
Frontiers Media S.A
04.12.2020
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Subjects | |
Online Access | Get full text |
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Summary: | Quantitative PCR analysis shows that the virulence plasmid of
serovar Typhimurium (pSLT) is a low-copy-number plasmid, with 1-2 copies per chromosome. However, fluorescence microscopy observation of pSLT labeled with a
fluorescent tag reveals cell-to-cell differences in the number of foci, which ranges from 1 to 8. As each focus must correspond to ≥1 plasmid copy, the number of foci can be expected to indicate the minimal number of pSLT copies per cell. A correlation is found between the number of foci and the bacterial cell volume. In contrast, heterogeneity in the number of loci appears to be independent of the cell volume and may have stochastic origin. As a consequence of copy number heterogeneity, expression of a pSLT-bone reporter gene shows high levels of cell-to-cell variation, especially in actively dividing cultures. These observations support the notion that low-copy-number plasmids can be a source of gene expression noise in bacterial populations. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Reviewed by: Christopher Morton Thomas, University of Birmingham, United Kingdom; Francisco P. Chávez, University of Chile, Chile Edited by: Eun-Jin Lee, Korea University, South Korea This article was submitted to Infectious Diseases, a section of the journal Frontiers in Microbiology |
ISSN: | 1664-302X 1664-302X |
DOI: | 10.3389/fmicb.2020.599931 |