The role of IS6110 in the evolution of Mycobacterium tuberculosis.
Members of the Mycobacterium tuberculosis complex contain the transposable element IS6110 which, due to its high numerical and positional polymorphism, has become a widely used marker in epidemiological studies. Here, we review the evidence that IS6110 is not simply a passive or 'junk' DNA sequence, but that, through its transposable activity, it is able to generate genotypic variation that translates into strain-specific phenotypic variation. We also speculate on the role that this variation has played in the evolution of M. tuberculosis and conclude that the presence of a moderate IS6110 copy number within the genome may provide the pathogen with a selective advantage that has aided its virulence.
McEvoy
Christopher R E
CR
DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Health Sciences, Stellenbosch University, Tygerberg, South Africa. cmcevoy@sun.ac.za
Falmer
Alecia A
AA
Gey van Pittius
Nicolaas C
NC
Victor
Thomas C
TC
van Helden
Paul D
PD
Warren
Robin M
RM
D004251:DNA Transposable Elements / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D014376:Tuberculosis / Q000235:genetics*; D014774:Virulence / Q000235:genetics
D004251:DNA Transposable Elements; D004269:DNA, Bacterial