RESUMO
To facilitate comparison of the genome maps of Mycobacterium tuberculosis and M. leprae, sequence data from the M. leprae sequencing project were used to design primers suitable for the amplification of short segments from conserved genes by the polymerase chain reaction. In most cases, both organisms yielded products of identical size that were then used as probes for a comparative genomic walk. The hybridization data often, but not always, revealed a similar organization of various regions of both genomes. This approach should be useful for systematic comparisons of (myco)bacterial genomes.
Assuntos
Genoma Bacteriano , Mycobacterium leprae/genética , Mycobacterium tuberculosis/genética , Sequência de Aminoácidos , Sequência de Bases , Passeio de Cromossomo , Primers do DNA , Genes Bacterianos , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Reação em Cadeia da Polimerase , Alinhamento de Sequência , Homologia de Sequência de AminoácidosRESUMO
In an attempt to unify the genetic and biological research on Mycobacterium leprae, the aetiological agent of leprosy, a cosmid library was constructed and then ordered by a combination of fingerprinting and hybridization techniques. The genome of M. leprae is represented by four contigs of overlapping clones which, together, account for nearly 2.8Mb of DNA. Several arguments suggest that the gaps between the contigs are small in size and that virtually complete coverage of the chromosome has been obtained. All of the cloned M. leprae genes have been positioned on the contig maps together with the 29 copies of the dispersed repetitive element, RLEP. These have been classified into four groups on the basis of differences in their organization. Several key housekeeping genes were identified and mapped by hybridization with heterologous probes, and the current genome map of this uncultivable pathogen comprises 72 loci.