Integrons in Xanthomonas: a source of species genome diversity.

Gillings, MR; Holley, MP; Stokes, HW; Holmes, AJ

Integrons in Xanthomonas: a source of species genome diversity.

Gillings, MR Holley, MP Stokes, HW Holmes, AJ

Permalink

Publication Type:: Journal Article
Citation:: Proc Natl Acad Sci U S A, 2005, 102 (12), pp. 4419 - 4424
Issue Date:: 2005-03-22

Closed Access

	Filename	Description	Size
	2008005620OK.pdf		372.06 kB	Adobe PDF	View/Open

Copyright Clearance Process

Recently Added
In Progress
Closed Access

This item is closed access and not available.

Full metadata record

Field	Value	Language
dc.contributor.author	Gillings, MR	en_US
dc.contributor.author	Holley, MP	en_US
dc.contributor.author	Stokes, HW	en_US
dc.contributor.author	Holmes, AJ	en_US
dc.date.issued	2005-03-22	en_US
dc.identifier.citation	Proc Natl Acad Sci U S A, 2005, 102 (12), pp. 4419 - 4424	en_US
dc.identifier.issn	0027-8424	en_US
dc.identifier.uri	http://hdl.handle.net/10453/8734
dc.description.abstract	Integrons are best known for assembling antibiotic resistance genes in clinical bacteria. They capture genes by using integrase-mediated site-specific recombination of mobile gene cassettes. Integrons also occur in the chromosomes of many bacteria, notably beta- and gamma-Proteobacteria. In a survey of Xanthomonas, integrons were found in all 32 strains representing 12 pathovars of two species. Their chromosomal location was downstream from the acid dehydratase gene, ilvD, suggesting that an integron was present at this site in the ancestral xanthomonad. There was considerable sequence and structural diversity among the extant integrons. The majority of integrase genes were predicted to be inactivated by frameshifts, stop codons, or large deletions, suggesting that the associated gene cassettes can no longer be mobilized. In support, groups of strains with the same deletions or stop codons/frameshifts in their integrase gene usually contained identical arrays of gene cassettes. In general, strains within individual pathovars had identical cassettes, and these exhibited no similarity to cassettes detected in other pathovars. The variety and characteristics of contemporary gene cassettes suggests that the ancestral integron had access to a diverse pool of these mobile elements, and that their genes originated outside the Xanthomonas genome. Subsequent inactivation of the integrase gene in particular lineages has largely fixed the gene cassette arrays in particular pathovars during their differentiation and specialization into ecological niches. The acquisition of diverse gene cassettes by different lineages within Xanthomonas has contributed to the species-genome diversity of the genus. The role of gene cassettes in survival on plant surfaces is currently unknown.	en_US
dc.language	eng	en_US
dc.relation.ispartof	Proc Natl Acad Sci U S A	en_US
dc.relation.isbasedon	10.1073/pnas.0406620102	en_US
dc.subject.mesh	Xanthomonas	en_US
dc.subject.mesh	Xanthomonas campestris	en_US
dc.subject.mesh	DNA, Bacterial	en_US
dc.subject.mesh	Chromosome Mapping	en_US
dc.subject.mesh	Evolution, Molecular	en_US
dc.subject.mesh	Species Specificity	en_US
dc.subject.mesh	Recombination, Genetic	en_US
dc.subject.mesh	Integrons	en_US
dc.subject.mesh	Genome, Bacterial	en_US
dc.subject.mesh	Molecular Sequence Data	en_US
dc.subject.mesh	Genetic Variation	en_US
dc.title	Integrons in Xanthomonas: a source of species genome diversity.	en_US
dc.type	Journal Article
utslib.citation.volume	12	en_US
utslib.citation.volume	102	en_US
utslib.location.activity	United States	en_US
utslib.for	0605 Microbiology	en_US
dc.location.activity	ISI:000227854800037	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
utslib.copyright.status	closed_access
pubs.issue	12	en_US
pubs.publication-status	Published	en_US
pubs.volume	102	en_US

Abstract:

Integrons are best known for assembling antibiotic resistance genes in clinical bacteria. They capture genes by using integrase-mediated site-specific recombination of mobile gene cassettes. Integrons also occur in the chromosomes of many bacteria, notably beta- and gamma-Proteobacteria. In a survey of Xanthomonas, integrons were found in all 32 strains representing 12 pathovars of two species. Their chromosomal location was downstream from the acid dehydratase gene, ilvD, suggesting that an integron was present at this site in the ancestral xanthomonad. There was considerable sequence and structural diversity among the extant integrons. The majority of integrase genes were predicted to be inactivated by frameshifts, stop codons, or large deletions, suggesting that the associated gene cassettes can no longer be mobilized. In support, groups of strains with the same deletions or stop codons/frameshifts in their integrase gene usually contained identical arrays of gene cassettes. In general, strains within individual pathovars had identical cassettes, and these exhibited no similarity to cassettes detected in other pathovars. The variety and characteristics of contemporary gene cassettes suggests that the ancestral integron had access to a diverse pool of these mobile elements, and that their genes originated outside the Xanthomonas genome. Subsequent inactivation of the integrase gene in particular lineages has largely fixed the gene cassette arrays in particular pathovars during their differentiation and specialization into ecological niches. The acquisition of diverse gene cassettes by different lineages within Xanthomonas has contributed to the species-genome diversity of the genus. The role of gene cassettes in survival on plant surfaces is currently unknown.

Please use this identifier to cite or link to this item:

http://hdl.handle.net/10453/8734