Bacteria Genomes - MYCOPLASMA MOBILE

Mycoplasmas are members of the class Mollicutes, a large group of bacteria that lack a cell wall and have a characteristically low G+C content. These diverse organisms are parasites in a wide range of hosts, including humans, animals, insects, plants, and cells grown in tissue culture. Aside from their role as potential pathogens, Mycoplasmas are of interest because they evolved from Gram-positive eubacteria by a drastic reduction of genome size, resulting in the loss of many biosynthetic abilities.

With genome sizes smaller than 1 Mb, they have been described as the "smallest free-living organisms", and are considered to be the best representatives for the concept of a minimal cell. M. mobile is not too closely related with M. genitalium and M. pneumoniae , the two species which were used as basis for the definition of the minimal genome (Hutchison et al. 1999), but it is a member of the same genus. Its genome sequence, combined with other Mycoplasma genome sequences, would be extremely valuable for the identification of a consensus minimal genome. To date, the complete nucleotide sequences of seven Mycoplasma genomes have been determined and additional species are subject to extensive sequencing efforts in an effort to find the minimal set of genes required to sustain independent life under laboratory growth conditions.

M. mobile is a non-pathogenic organism, yet shares many of the simple features found in the pathogenic species. Research on this organism can be performed without the additional regulatory and safety issues necessary with other mycoplasma species.

M. mobile has been isolated from a fresh-water fish, the tench, and as such is the first instance of a Mycoplasma which colonizes an aquatic organism.

M. mobile glides much faster and more robustly than any other Mycoplasma sequenced to date. The availability of its genome sequence provides a powerful tool for comparative genomics targeting the identification of genes necessary for locomotion.

References:

http://www.broad.mit.edu/annotation/microbes/mycoplasma/background.html