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Co-evolution within structured bacterial communities results in multiple expansion of CRISPR loci and enhanced immunity
Type II CRISPR-Cas systems provide immunity against phages and plasmids that infect bacteria through the insertion of a short sequence from the invader’s genome, known as the ‘spacer’, into the CRISPR locus. Spacers are transcribed into guide RNAs that direct the Cas9 nuclease to its target on the i...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
eLife Sciences Publications, Ltd
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7105378/ https://www.ncbi.nlm.nih.gov/pubmed/32223887 http://dx.doi.org/10.7554/eLife.53078 |
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author | Pyenson, Nora C Marraffini, Luciano A |
author_facet | Pyenson, Nora C Marraffini, Luciano A |
author_sort | Pyenson, Nora C |
collection | PubMed |
description | Type II CRISPR-Cas systems provide immunity against phages and plasmids that infect bacteria through the insertion of a short sequence from the invader’s genome, known as the ‘spacer’, into the CRISPR locus. Spacers are transcribed into guide RNAs that direct the Cas9 nuclease to its target on the invader. In liquid cultures, most bacteria acquire a single spacer. Multiple spacer integration is a rare event which significance for immunity is poorly understood. Here, we found that when phage infections occur on solid media, a high proportion of the surviving colonies display complex morphologies that contain cells with multiple spacers. This is the result of the viral-host co-evolution, in which the immunity provided by the initial acquired spacer is easily overcome by escaper phages. Our results reveal the versatility of CRISPR-Cas immunity, which can respond with both single or multiple spacer acquisition schemes to solve challenges presented by different environments. |
format | Online Article Text |
id | pubmed-7105378 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | eLife Sciences Publications, Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-71053782020-04-01 Co-evolution within structured bacterial communities results in multiple expansion of CRISPR loci and enhanced immunity Pyenson, Nora C Marraffini, Luciano A eLife Microbiology and Infectious Disease Type II CRISPR-Cas systems provide immunity against phages and plasmids that infect bacteria through the insertion of a short sequence from the invader’s genome, known as the ‘spacer’, into the CRISPR locus. Spacers are transcribed into guide RNAs that direct the Cas9 nuclease to its target on the invader. In liquid cultures, most bacteria acquire a single spacer. Multiple spacer integration is a rare event which significance for immunity is poorly understood. Here, we found that when phage infections occur on solid media, a high proportion of the surviving colonies display complex morphologies that contain cells with multiple spacers. This is the result of the viral-host co-evolution, in which the immunity provided by the initial acquired spacer is easily overcome by escaper phages. Our results reveal the versatility of CRISPR-Cas immunity, which can respond with both single or multiple spacer acquisition schemes to solve challenges presented by different environments. eLife Sciences Publications, Ltd 2020-03-30 /pmc/articles/PMC7105378/ /pubmed/32223887 http://dx.doi.org/10.7554/eLife.53078 Text en © 2020, Pyenson and Marraffini http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited. |
spellingShingle | Microbiology and Infectious Disease Pyenson, Nora C Marraffini, Luciano A Co-evolution within structured bacterial communities results in multiple expansion of CRISPR loci and enhanced immunity |
title | Co-evolution within structured bacterial communities results in multiple expansion of CRISPR loci and enhanced immunity |
title_full | Co-evolution within structured bacterial communities results in multiple expansion of CRISPR loci and enhanced immunity |
title_fullStr | Co-evolution within structured bacterial communities results in multiple expansion of CRISPR loci and enhanced immunity |
title_full_unstemmed | Co-evolution within structured bacterial communities results in multiple expansion of CRISPR loci and enhanced immunity |
title_short | Co-evolution within structured bacterial communities results in multiple expansion of CRISPR loci and enhanced immunity |
title_sort | co-evolution within structured bacterial communities results in multiple expansion of crispr loci and enhanced immunity |
topic | Microbiology and Infectious Disease |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7105378/ https://www.ncbi.nlm.nih.gov/pubmed/32223887 http://dx.doi.org/10.7554/eLife.53078 |
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