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Comparison of Mycobacterium tuberculosis genomes reveals frequent deletions in a 20 kb variable region in clinical isolates
Author(s) -
Ho Timothy B. L.,
Robertson Brian D.,
Taylor G. Michael,
Shaw Rory J.,
Young Douglas B.
Publication year - 2000
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/1097-0061(200012)17:4<272::aid-yea48>3.0.co;2-2
Subject(s) - biology , insertion sequence , mycobacterium tuberculosis , genetics , genome , dna transposable elements , gene , inverted repeat , direct repeat , restriction fragment length polymorphism , mycobacterium tuberculosis complex , tuberculosis , transposable element , genotype , medicine , pathology
The Mycobacterium tuberculosis complex is associated with a remarkably low level of structural gene polymorphism. As part of a search for alternative forms of genetic variation that may act as a source of biological diversity in M. tuberculosis , we have identified a region of the genome that is highly variable amongst a panel of unrelated clinical isolates. Fifteen of 24 isolates examined contained one or more copies of the M. tuberculosis ‐specific IS 6110 insertion element within this 20 kb variable region. In nine of the isolates, including the laboratory‐passaged strain H37Rv, genomic deletions were identified, resulting in loss of between two and 13 genes. In each case, deletions were associated with the presence of a copy of the IS 6110 element. Absence of flanking tri‐ or tetra‐nucleotide repeats identified homologous recombination between adjacent IS 6110 elements as the most likely mechanism of the deletion events. IS 6110 insertion into hot‐spots within the genome of M. tuberculosis provides a mechanism for generation of genetic diversity involving a high frequency of insertions and deletions. Copyright © 2000 John Wiley & Sons, Ltd.