Mycobacterium bovis is the causative agent of tuberculosis in a number animal species and man, with global annual losses to agriculture of $three billion. The human burden of tuberculosis resulting from the bovine tubercle bacillus is still in large part unknown. M. Bovis turned into additionally the progenitor for the M. Bovis bacillus Calmette-vaccine strain, the maximum extensively used human vaccine. Here we describe the 4,345,492-bp genome collection of M. Bovis AF2122/97 and its evaluation with the genomes of Mycobacterium tuberculosis and Mycobacterium leprae. Strikingly, the genome collection of M. Bovis is 99.95% identical to that of M. Tuberculosis, however deletion of genetic records has led to a discounted genome size. Comparison with M. Leprae reveals a number of common gene losses, suggesting the removal of purposeful redundancy. Cell wall additives and secreted proteins display the greatest variation, indicating their ability role in host-bacillus interactions or immune evasion. Furthermore, there arenany genes precise to M. Bovis, implying that differential gene expression may be the key to the host tropisms of human and bovine bacilli. The genome collection therefore offers principal insight on the evolution, host preference, and pathobiology of M. Bovis.