Conjugating DNA into Mycobacteria

Bacterial conjugation is a phenomenon that is more widespread than was originally thought. It medtates genetrc exchange not only between cells of the same species, but also between a wide variety of unrelated organisms. Conjugation between gram-negative and gram-positive bacteria was first demonstrated using recombinant-shuttle plasmids (1 ). In Mycobacterium, the shuttle-plasmid pMY10 was introduced to Mycobacterium smegmatis from Escherichia coli (2 ), as was the naturally occurring plasmid RSF1010 (3 ). More dramatic examples of conjugation have been shown between E. coli and yeast cells and from Agrobacterium spp. to tobacco-plant cells (4 ,5 ). This would suggest that in the horizontal transfer of genetic material, few barriers exist that prevent the acquisition of new genetic information, rather the ability of the DNA to be maintained in the new host would seem to be the main barrier to be overcome.