Skip Navigation


MBE Advance Access originally published online on June 1, 2007
Molecular Biology and Evolution 2007 24(8):1861-1871; doi:10.1093/molbev/msm111
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Supplementary Material
Right arrowOA All Versions of this Article:
24/8/1861    most recent
msm111v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Google Scholar
Right arrow Articles by Becq, J.
Right arrow Articles by Deschavanne, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Becq, J.
Right arrow Articles by Deschavanne, P.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 2007 The Authors.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Research Articles

Contribution of Horizontally Acquired Genomic Islands to the Evolution of the Tubercle Bacilli

Jennifer Becq*, Maria Cristina Gutierrez{dagger}, Vania Rosas-Magallanes{ddagger}, Jean Rauzier{ddagger}, Brigitte Gicquel{ddagger}, Olivier Neyrolles{ddagger},§,1,2 and Patrick Deschavanne*,1

* Genomics and Molecular Bioinformatics, Inserm U726 - Université Paris 7, Paris, France
{dagger} Unit of Biodiversity of Emerging Pathogenic Bacteria, Institut Pasteur, Paris, France
{ddagger} Unit of Mycobacterial Genetics, Institut Pasteur, Paris, France
§ Centre National de la Recherche Scientifique, URA 2172, Paris, France

E-mail: neyrolle{at}pasteur.fr.

Accepted for publication May 29, 2007.

The contribution of horizontal gene transfer (HGT) to the evolution of Mycobacterium tuberculosis — the main causal agent of tuberculosis in humans — and closely related members of the M. tuberculosis complex remains poorly understood. Using a combination of genome-wide parametric analyses, we have identified 48 M. tuberculosis chromosomal regions with atypical characteristics, potentially due to HGT. These specific regions account for 4.5% of the genome (199 kb) and include 256 genes. Many display features typical of the genomic islands found in other bacteria, including residual material from mobile genetic elements, flanking direct repeats, insertion in the vicinity of tRNA sequences, and genes with putative or documented virulence functions. Southern blotting analysis of nine of these 48 regions confirmed their presence in "Mycobacterium prototuberculosis," the ancestral species of the M. tuberculosis complex. Finally, our results strongly suggest that the ancestor of the tubercle bacilli was an environmental bacillus that exchanged genetic material with other bacterial species, including Proteobacteria in particular, present in its surroundings. This study describes a rational approach to searching for mycobacterial virulence genes, and highlights the importance of dissecting gene transfer networks to improve our understanding of mycobacterial pathogenicity and evolution.

Key Words: Horizontal gene transfer • Mycobacterium tuberculosis complex • Tuberculosis • Virulence

1 These authors share senior authorship.

2 Present address: O. Neyrolles Institut Pasteur, Unit of Mycobacterial Genetics 28 rue du Dr Roux, 75015 Paris, France Tel: +33 (0)1 45 68 88 40, Fax: +33 (0)1 45 68 88 43.

Jennifer Wernegreen, Associate Editor


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Mol Biol EvolHome page
L. A. S. Snyder, S. McGowan, M. Rogers, E. Duro, E. O'Farrell, and N. J. Saunders
The Repertoire of Minimal Mobile Elements in the Neisseria Species and Evidence That These Are Involved in Horizontal Gene Transfer in Other Bacteria
Mol. Biol. Evol., December 1, 2007; 24(12): 2802 - 2815.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.