Detecting the molecular scars of evolution in the Mycobacterium tuberculosis complex by analyzing interrupted coding...

Area of Science:

• Microbiology
• Genomics
• Evolutionary Biology

Background:

• Bacterial genomes contain interrupted coding sequences (ICDSs) with frameshifts or stop codons.
• The functional and evolutionary significance of these ICDSs remains largely unexplored.

Purpose of the Study:

• To conduct a comparative analysis of ICDSs in various Mycobacterium species.
• To investigate the phenotypic impact and evolutionary significance of ICDSs.

Main Methods:

• Comparative genomic analysis of ICDSs across M. tuberculosis, M. bovis, and M. africanum isolates.
• In silico analysis of specific lineages, such as the W-Beijing lineage of M. tuberculosis.
• Sequencing analysis of ICDSs in a panel of clinical M. tuberculosis strains.

Main Results:

• ICDSs were classified as common or strain-specific, reflecting evolutionary divergence.
• Strain-specific ICDSs act as molecular signatures for identifying strains, lineages, and species.
• The W-Beijing lineage shows distinct ICDS profiles, correlating with virulence and divergence.
• ICDS formation is not linked to promoter mutations, suggesting alternative pseudogene formation mechanisms.

Conclusions:

• The correlation between ICDSs, function, and phenotypes has significant evolutionary implications.
• ICDSs can serve as targets for studying selective pressures and host-pathogen relationships.
• This analytical approach is applicable to other closely related bacterial species with available genome sequences.