Table 1.
Workflow summarizing the steps followed in the identification of HGT genes in mycobacteria.
Figure 1.
Phylogeny as inferred from the pyr-redox gene.
The phylogenetic tree was obtained using maximum likelihood with the amino acid dataset. Numbers at the nodes represent bootstrap percentages. Only high bootstraps (>75) are indicated.
Figure 2.
A. polyphaga co-cultured with M. avium and L. pneumophila for 5 days.
A) The number of L. pneumophila colonies was obtained after plating the lysate of L. pneumophila and A. polyphaga culture or L. pneumophila, M. avium and A. polyphaga co-culture in BCYE agar medium. B) The number of M. avium colonies was obtained after plating the lysate of M. avium and A. polyphaga culture or M. avium, L. pneumophila and A. polyphaga co-culture in 7H10 agar medium. Data points are the means of triplicate wells, and the standard errors are represented by error bars.
Figure 3.
Schematic representation of two alternative explanations of the evolutionary history of the pyridine nucleotide disulfide oxidoreductase gene.
Dashed arrows indicate the possible lateral transfer of the gene. First hypothesis: The gene encoding pyr-redox exists in the gamma-Proteobacteria species and is absent in D. discoideum and T. thermophila. This gene was acquired from Legionella spp. by Mycobacterium spp., D. discoideum and T. thermophila. Second hypothesis: The gene encoding pyr-redox was lost from Legionella spp., D. discoideum and T. thermophila and was acquired later from Mycobacterium spp. T0 corresponds to the time of observation and T-x to the time when the event occurred.
Figure 4.
Schematic representation of HGT and molecular clock.
The left tree shows the relationships and approximate dates of divergence of the species. The phylogeny was reconstructed based on 16S and 18S rDNA sequences, and the expected divergence was calculated as a function of time, 1–2% per 50 MYA. The right tree shows the relationships among species based on pyr redox protein. The circles on the nodes indicate the radiation of Legionella spp. (33 MYA) and the separation of gamma-Proteobacteria spp. (267 MYA).