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The Genome Sequence of “Candidatus Fokinia solitaria”: Insights on Reductive Evolution in Rickettsiales
“Candidatus Fokinia solitaria” is an obligate intracellular endosymbiont of a unicellular eukaryote, a ciliate of the genus Paramecium. Here, we present the genome sequence of this bacterium and subsequent analysis. Phylogenomic analysis confirmed the previously reported positioning of the symbiont...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Oxford University Press
2018
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5905368/ https://www.ncbi.nlm.nih.gov/pubmed/29659807 http://dx.doi.org/10.1093/gbe/evy072 |
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author | Floriano, Anna M Castelli, Michele Krenek, Sascha Berendonk, Thomas U Bazzocchi, Chiara Petroni, Giulio Sassera, Davide |
author_facet | Floriano, Anna M Castelli, Michele Krenek, Sascha Berendonk, Thomas U Bazzocchi, Chiara Petroni, Giulio Sassera, Davide |
author_sort | Floriano, Anna M |
collection | PubMed |
description | “Candidatus Fokinia solitaria” is an obligate intracellular endosymbiont of a unicellular eukaryote, a ciliate of the genus Paramecium. Here, we present the genome sequence of this bacterium and subsequent analysis. Phylogenomic analysis confirmed the previously reported positioning of the symbiont within the “Candidatus Midichloriaceae” family (order Rickettsiales), as well as its high sequence divergence from other members of the family, indicative of fast sequence evolution. Consistently with this high evolutionary rate, a comparative genomic analysis revealed that the genome of this symbiont is the smallest of the Rickettsiales to date. The reduced genome does not present flagellar genes, nor the pathway for the biosynthesis of lipopolysaccharides (present in all the other so far sequenced members of the family “Candidatus Midichloriaceae”) or genes for the Krebs cycle (present, although not always complete, in Rickettsiales). These results indicate an evolutionary trend toward a stronger dependence on the host, in comparison with other members of the family. Two alternative scenarios are compatible with our results; “Candidatus Fokinia solitaria” could be either a recently evolved, vertically transmitted mutualist, or a parasite with a high host-specificity. |
format | Online Article Text |
id | pubmed-5905368 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Oxford University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-59053682018-04-23 The Genome Sequence of “Candidatus Fokinia solitaria”: Insights on Reductive Evolution in Rickettsiales Floriano, Anna M Castelli, Michele Krenek, Sascha Berendonk, Thomas U Bazzocchi, Chiara Petroni, Giulio Sassera, Davide Genome Biol Evol Genome Report “Candidatus Fokinia solitaria” is an obligate intracellular endosymbiont of a unicellular eukaryote, a ciliate of the genus Paramecium. Here, we present the genome sequence of this bacterium and subsequent analysis. Phylogenomic analysis confirmed the previously reported positioning of the symbiont within the “Candidatus Midichloriaceae” family (order Rickettsiales), as well as its high sequence divergence from other members of the family, indicative of fast sequence evolution. Consistently with this high evolutionary rate, a comparative genomic analysis revealed that the genome of this symbiont is the smallest of the Rickettsiales to date. The reduced genome does not present flagellar genes, nor the pathway for the biosynthesis of lipopolysaccharides (present in all the other so far sequenced members of the family “Candidatus Midichloriaceae”) or genes for the Krebs cycle (present, although not always complete, in Rickettsiales). These results indicate an evolutionary trend toward a stronger dependence on the host, in comparison with other members of the family. Two alternative scenarios are compatible with our results; “Candidatus Fokinia solitaria” could be either a recently evolved, vertically transmitted mutualist, or a parasite with a high host-specificity. Oxford University Press 2018-04-05 /pmc/articles/PMC5905368/ /pubmed/29659807 http://dx.doi.org/10.1093/gbe/evy072 Text en © The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. http://creativecommons.org/licenses/by-nc/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com |
spellingShingle | Genome Report Floriano, Anna M Castelli, Michele Krenek, Sascha Berendonk, Thomas U Bazzocchi, Chiara Petroni, Giulio Sassera, Davide The Genome Sequence of “Candidatus Fokinia solitaria”: Insights on Reductive Evolution in Rickettsiales |
title | The Genome Sequence of “Candidatus Fokinia solitaria”: Insights on Reductive Evolution in Rickettsiales |
title_full | The Genome Sequence of “Candidatus Fokinia solitaria”: Insights on Reductive Evolution in Rickettsiales |
title_fullStr | The Genome Sequence of “Candidatus Fokinia solitaria”: Insights on Reductive Evolution in Rickettsiales |
title_full_unstemmed | The Genome Sequence of “Candidatus Fokinia solitaria”: Insights on Reductive Evolution in Rickettsiales |
title_short | The Genome Sequence of “Candidatus Fokinia solitaria”: Insights on Reductive Evolution in Rickettsiales |
title_sort | genome sequence of “candidatus fokinia solitaria”: insights on reductive evolution in rickettsiales |
topic | Genome Report |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5905368/ https://www.ncbi.nlm.nih.gov/pubmed/29659807 http://dx.doi.org/10.1093/gbe/evy072 |
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