  Tuberculosis is one of the most lethal contagious diseases caused by
Mycobacterium tuberculosis (MTB), in many cases, the infected did not show any
symptoms, because the bacilli entered the dormant stage in granulomas. The
dormant stage of MTB is also associated with higher resistance to drugs and the
immune system. Among multiple epigenetic regulations critical to MTB stress
responses, DNA methylation is necessary for the survival of MTB in hypoxic
conditions, which is a common stress event during granuloma formation. This
review gathers previous findings and demonstrates a meta-analysis by collecting
hypoxia gene expression data from several articles and perform association
analysis between those genes and methylation site profiles across whole genomes
of representative strains pf lineage 2 and 4. While more data is required for
more conclusive support, our results suggest that methylation sites in the
possible promoter regions may induce differential gene regulation in hypoxia.
