Extreme Polyploidy of Carsonella, an Organelle-Like Bacterium with a Drastically Reduced Genome
ABSTRACT Polyploidy is the state of having multiple copies of the genome within a nucleus or a cell, which has repeatedly evolved across the domains of life. Whereas most bacteria are monoploid, some bacterial species and endosymbiotic organelles that are derived from bacteria are stably polyploid....
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| Format: | Article |
| Language: | English |
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American Society for Microbiology
2022-06-01
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| Series: | Microbiology Spectrum |
| Subjects: | |
| Online Access: | https://journals.asm.org/doi/10.1128/spectrum.00350-22 |
| _version_ | 1811238139432271872 |
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| author | Atsushi Nakabachi Nancy A. Moran |
| author_facet | Atsushi Nakabachi Nancy A. Moran |
| author_sort | Atsushi Nakabachi |
| collection | DOAJ |
| description | ABSTRACT Polyploidy is the state of having multiple copies of the genome within a nucleus or a cell, which has repeatedly evolved across the domains of life. Whereas most bacteria are monoploid, some bacterial species and endosymbiotic organelles that are derived from bacteria are stably polyploid. In the present study, using absolute quantitative PCR, we assessed the ploidy of Candidatus Carsonella ruddii (Gammaproteobacteria, Oceanospirillales), the obligate symbiont of the hackberry petiole gall psyllid, Pachypsylla venusta (Hemiptera, Psylloidea). The genome of this symbiont is one of the smallest known for cellular organisms, at 160 kb. The analysis revealed that Carsonella within a single bacteriocyte has ∼6 × 104 copies of the genome, indicating that some Carsonella cells can contain thousands or even tens of thousands of genomic copies per cell. The basis of polyploidy of Carsonella is unknown, but it potentially plays a role in the repair of DNA damage through homologous recombination. IMPORTANCE Mitochondria and plastids are endosymbiotic organelles in eukaryotic cells and are derived from free-living bacteria. They have many highly reduced genomes from which numerous genes have been transferred to the host nucleus. Similar, but more recently established, symbiotic systems are observed in some insect lineages. Although the genomic sequence data of such bacterial symbionts are rapidly accumulating, little is known about their ploidy. The present study revealed that a bacterium with a drastically reduced genome is an extreme polyploid, which is reminiscent of the case of organelles. |
| first_indexed | 2024-04-12T12:36:34Z |
| format | Article |
| id | doaj.art-acf6a8ddb7f64a93948154280126863b |
| institution | Directory Open Access Journal |
| issn | 2165-0497 |
| language | English |
| last_indexed | 2024-04-12T12:36:34Z |
| publishDate | 2022-06-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | Microbiology Spectrum |
| spelling | doaj.art-acf6a8ddb7f64a93948154280126863b2022-12-22T03:32:54ZengAmerican Society for MicrobiologyMicrobiology Spectrum2165-04972022-06-0110310.1128/spectrum.00350-22Extreme Polyploidy of Carsonella, an Organelle-Like Bacterium with a Drastically Reduced GenomeAtsushi Nakabachi0Nancy A. Moran1Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, Toyohashi, Aichi, JapanSection of Integrative Biology, University of Texas, Austin, Texas, USAABSTRACT Polyploidy is the state of having multiple copies of the genome within a nucleus or a cell, which has repeatedly evolved across the domains of life. Whereas most bacteria are monoploid, some bacterial species and endosymbiotic organelles that are derived from bacteria are stably polyploid. In the present study, using absolute quantitative PCR, we assessed the ploidy of Candidatus Carsonella ruddii (Gammaproteobacteria, Oceanospirillales), the obligate symbiont of the hackberry petiole gall psyllid, Pachypsylla venusta (Hemiptera, Psylloidea). The genome of this symbiont is one of the smallest known for cellular organisms, at 160 kb. The analysis revealed that Carsonella within a single bacteriocyte has ∼6 × 104 copies of the genome, indicating that some Carsonella cells can contain thousands or even tens of thousands of genomic copies per cell. The basis of polyploidy of Carsonella is unknown, but it potentially plays a role in the repair of DNA damage through homologous recombination. IMPORTANCE Mitochondria and plastids are endosymbiotic organelles in eukaryotic cells and are derived from free-living bacteria. They have many highly reduced genomes from which numerous genes have been transferred to the host nucleus. Similar, but more recently established, symbiotic systems are observed in some insect lineages. Although the genomic sequence data of such bacterial symbionts are rapidly accumulating, little is known about their ploidy. The present study revealed that a bacterium with a drastically reduced genome is an extreme polyploid, which is reminiscent of the case of organelles.https://journals.asm.org/doi/10.1128/spectrum.00350-22ploidybacteriome-associated symbiontssmall genomeinsects |
| spellingShingle | Atsushi Nakabachi Nancy A. Moran Extreme Polyploidy of Carsonella, an Organelle-Like Bacterium with a Drastically Reduced Genome Microbiology Spectrum ploidy bacteriome-associated symbionts small genome insects |
| title | Extreme Polyploidy of Carsonella, an Organelle-Like Bacterium with a Drastically Reduced Genome |
| title_full | Extreme Polyploidy of Carsonella, an Organelle-Like Bacterium with a Drastically Reduced Genome |
| title_fullStr | Extreme Polyploidy of Carsonella, an Organelle-Like Bacterium with a Drastically Reduced Genome |
| title_full_unstemmed | Extreme Polyploidy of Carsonella, an Organelle-Like Bacterium with a Drastically Reduced Genome |
| title_short | Extreme Polyploidy of Carsonella, an Organelle-Like Bacterium with a Drastically Reduced Genome |
| title_sort | extreme polyploidy of carsonella an organelle like bacterium with a drastically reduced genome |
| topic | ploidy bacteriome-associated symbionts small genome insects |
| url | https://journals.asm.org/doi/10.1128/spectrum.00350-22 |
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