Bacteria belonging to the class Mollicutes were among the first ones to be selected for complete genome sequencing because of the minimal size of their genomes and of their pathogenicity for humans and a broad range of animals and plants. As the number of available mollicute genomes increases, comparative genomics analysis within this model group of organisms becomes more and more instructive.

However, such an analysis is difficult to carry out without a suitable platform gathering not only the original annotations but also relevant information available in public databases or obtained applying common bioinformatics methods.

With the aim of solving these difficulties, we have developed a web-accessible database named MolliGen.
After selecting a set of genomes the user can launch various types of searches based on annotation, position on the chromosomes or sequence similarity. In addition, relationships of putative orthology have been pre-computed to allow differential genome queries.
The results are presented in a table format with multiple links to public databases and to bioinformatic analyses such as multiple alignments or BLAST search.
Specific tools were also developed for the graphical visualisation of the results, including a multi-genome browser for displaying dynamic pictures with clickable objects and for viewing relationships of pre-computed similarity.
MolliGen is designed to integrate all the complete genomes of mollicutes as they will become available.