As more mycobacterial genomes are sequenced, a picture is emerging that Distributive Conjugal Transfer may have shuffled the genomes of environmental mycobacteria to create a strain that was particularly well suited for growth in mammalian lungs.
Of the nearly 7,000 genes in the mycobacterial genome, one region spanning just 6 genes appears to be key in determining whether a mycobacterial strain will be a donor or recipient when it comes to mating.