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Suzuki Y, Assad-Garcia N, Kostylev M, Noskov VN, Wise KS, Karas BJ, Stam J, Montague MG, Hanly TJ, Enriquez NJ, Ramon A, Goldgof GM, Richter RA, Vashee S, Chuang RY, Winzeler EA, Hutchison CA, Gibson DG, Smith HO, Glass JI, Venter JC. Bacterial genome reduction using the progressive clustering of deletions via yeast sexual cycling. Genome Res 2015; 25:435-44. [PMID: 25654978 PMCID: PMC4352883 DOI: 10.1101/gr.182477.114] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The availability of genetically tractable organisms with simple genomes is critical for the rapid, systems-level understanding of basic biological processes. Mycoplasma bacteria, with the smallest known genomes among free-living cellular organisms, are ideal models for this purpose, but the natural versions of these cells have genome complexities still too great to offer a comprehensive view of a fundamental life form. Here we describe an efficient method for reducing genomes from these organisms by identifying individually deletable regions using transposon mutagenesis and progressively clustering deleted genomic segments using meiotic recombination between the bacterial genomes harbored in yeast. Mycoplasmal genomes subjected to this process and transplanted into recipient cells yielded two mycoplasma strains. The first simultaneously lacked eight singly deletable regions of the genome, representing a total of 91 genes and ∼10% of the original genome. The second strain lacked seven of the eight regions, representing 84 genes. Growth assay data revealed an absence of genetic interactions among the 91 genes under tested conditions. Despite predicted effects of the deletions on sugar metabolism and the proteome, growth rates were unaffected by the gene deletions in the seven-deletion strain. These results support the feasibility of using single-gene disruption data to design and construct viable genomes lacking multiple genes, paving the way toward genome minimization. The progressive clustering method is expected to be effective for the reorganization of any mega-sized DNA molecules cloned in yeast, facilitating the construction of designer genomes in microbes as well as genomic fragments for genetic engineering of higher eukaryotes.
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Affiliation(s)
- Yo Suzuki
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA;
| | - Nacyra Assad-Garcia
- Synthetic Biology Group, J. Craig Venter Institute, Rockville, Maryland 20850, USA
| | - Maxim Kostylev
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA
| | - Vladimir N Noskov
- Synthetic Biology Group, J. Craig Venter Institute, Rockville, Maryland 20850, USA
| | - Kim S Wise
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA; Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri 65212, USA
| | - Bogumil J Karas
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA
| | - Jason Stam
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA
| | - Michael G Montague
- Synthetic Biology Group, J. Craig Venter Institute, Rockville, Maryland 20850, USA
| | - Timothy J Hanly
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA
| | - Nico J Enriquez
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA
| | - Adi Ramon
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA
| | - Gregory M Goldgof
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA; University of California, San Diego, School of Medicine, La Jolla, California 92093, USA
| | - R Alexander Richter
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA
| | - Sanjay Vashee
- Synthetic Biology Group, J. Craig Venter Institute, Rockville, Maryland 20850, USA
| | - Ray-Yuan Chuang
- Synthetic Biology Group, J. Craig Venter Institute, Rockville, Maryland 20850, USA
| | - Elizabeth A Winzeler
- University of California, San Diego, School of Medicine, La Jolla, California 92093, USA
| | - Clyde A Hutchison
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA
| | - Daniel G Gibson
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA
| | - Hamilton O Smith
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA
| | - John I Glass
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA; Synthetic Biology Group, J. Craig Venter Institute, Rockville, Maryland 20850, USA
| | - J Craig Venter
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, California 92037, USA; Synthetic Biology Group, J. Craig Venter Institute, Rockville, Maryland 20850, USA
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van Brabant AJ, Fangman WL, Brewer BJ. Active role of a human genomic insert in replication of a yeast artificial chromosome. Mol Cell Biol 1999; 19:4231-40. [PMID: 10330163 PMCID: PMC104382 DOI: 10.1128/mcb.19.6.4231] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Yeast artificial chromosomes (YACs) are a common tool for cloning eukaryotic DNA. The manner by which large pieces of foreign DNA are assimilated by yeast cells into a functional chromosome is poorly understood, as is the reason why some of them are stably maintained and some are not. We examined the replication of a stable YAC containing a 240-kb insert of DNA from the human T-cell receptor beta locus. The human insert contains multiple sites that serve as origins of replication. The activity of these origins appears to require the yeast ARS consensus sequence and, as with yeast origins, additional flanking sequences. In addition, the origins in the human insert exhibit a spacing, a range of activation efficiencies, and a variation in times of activation during S phase similar to those found for normal yeast chromosomes. We propose that an appropriate combination of replication origin density, activation times, and initiation efficiencies is necessary for the successful maintenance of YAC inserts.
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Affiliation(s)
- A J van Brabant
- Department of Genetics, University of Washington, Seattle, Washington 98195-7360, USA
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