Comparative genomics of prokaryotes

Comparative genomics methods enable the reconstruction of bacterial regulatory networks using availableexperimental data. The analyses of type III secretion and SOS response regulatory networks illustrateinstances of convergent and divergent evolution of these regulatory systems, showcasing the power of formalancestral state reconstruction at inferring the evolutionary history of regulatory networks.Gene order inprokaryotes is conserved to a much lesser extent than protein sequences.Only several operons, primarilythose that code for physically interacting proteins, are conserved in all or most of the bacterial and archaealgenomes. Multiple genome alignments are a resource for studies on operon rearrangement and disruption,which is central to our understanding of the evolution of prokaryotic genomes.The coverage of the archaeal genomes was only slightly lower than that of bacterial genomes. The majorityof the conserved gene strings are known operons, with the ribosomal super operon being the top scoringstring in most genome comparisons. Subsequent comparisons of the sequenced bacterial and archaealgenomes have shown that even most of the operons are extensively rearranged during evolution. Only a fewoperons, typically coding for physically interacting proteins, are conserved in all or most of the genomes.Inthis research We were interested in systematically and quantitatively exploring the conservation of gene orderamong the ۲۵ currently available complete bacterial and archaeal genomes and its dependence on theevolutionary distance between these genomes, and in assessing the potential of such comparisons foridentification of previously undetected operons and prediction of gene functions

کلیدواژه ها:

Comparative genomics ، Prokaryotes ، Ribosome ، Operon ، Bacterial genomes