Microsatellite polymorphism across the M. tuberculosis and M. bovis genomes: Implications on genome evolution and plasticity

Sreenu, V. B. , Kumar, P., Nagaraju, J. and Nagarajaram, H. A. (2006) Microsatellite polymorphism across the M. tuberculosis and M. bovis genomes: Implications on genome evolution and plasticity. BMC Genomics, 7(1), 78. (doi: 10.1186/1471-2164-7-78) (PMID:16603092) (PMCID:PMC1501019)

Abstract

Background: Microsatellites are the tandem repeats of nucleotide motifs of size 1–6 bp observed in all known genomes. These repeats show length polymorphism characterized by either insertion or deletion (indels) of the repeat units, which in and around the coding regions affect transcription and translation of genes. Results: Systematic comparison of all the equivalent microsatellites in the coding regions of the three mycobacterial genomes, viz. Mycobacterium tuberculosis H37Rv, Mycobacterium tuberculosis CDC1551 and Mycobacterium bovis, revealed for the first time the presence of several polymorphic microsatellites. The coding regions affected by frame-shifts owing to microsatellite indels have undergone changes indicative of gene fission/fusion, premature termination and length variation. Interestingly, the genes affected by frame-shift mutations code for membrane proteins, transporters, PPE, PE_PGRS, cell-wall synthesis proteins and hypothetical proteins. Conclusion: This study has revealed the role of microsatellite indel mutations in imparting novel functions and a certain degree of plasticity to the mycobacterial genomes. There seems to be some correlation between microsatellite polymorphism and the variations in virulence, host-pathogen interactions mediated by surface antigen variations, and adaptation of the pathogens. Several of the polymorphic microsatellites reported in this study can be tested for their polymorphic nature by screening clinical isolates and various mycobacterial strains, for establishing correlations between microsatellite polymorphism and the phenotypic variations among these pathogens.

• Item Type: Articles
• Additional Information: This work was supported by the core grants of CDFD and, V.B.S and P.K greatly acknowledge the Council of Scientific and Industrial Research (CSIR), India, for the fellowships.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Vattipally, Dr Sreenu
• Authors: Sreenu, V. B., Kumar, P., Nagaraju, J., and Nagarajaram, H. A.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity; College of Medical Veterinary and Life Sciences > School of Infection & Immunity > Centre for Virus Research
• Journal Name: BMC Genomics
• Publisher: Biomed Central
• ISSN: 1471-2164
• ISSN (Online): 1471-2164
• Copyright Holders: Copyright © 2006 Sreenu et al.
• First Published: First published in BMC Genomics 7:78
• Publisher Policy: Reproduced under a Creative Commons license