Cell cycle control in bacteria and yeast: a case of convergent evolution?
Superficially similar traits in phylogenetically unrelated species often result from adaptation to common selection pressures. Examples of convergent evolution are known at the levels of whole organisms, organ systems, gene networks and specific proteins. The phenotypic properties of living things, on the other hand, are determined in large part by complex networks of interacting proteins. Here we present a mathematical model of the network of proteins that controls DNA synthesis and cell division in the alpha-proteobacterium, Caulobacter crescentus. By comparing the protein regulatory circuits for cell reproduction in Caulobacter with that in budding yeast (Saccharomyces cerevisiae), we suggest that convergent evolution may have created similar molecular reaction networks in order to accomplish the same purpose of coordinating DNA synthesis to cell division. Although the genes and proteins involved in cell cycle regulation in prokaryotes and eukaryotes are very different and (apparently) phylogenetically unrelated, they seem to be wired together in similar regulatory networks, which coordinate cell cycle events by identical dynamical principles.
Brazhnik
Paul
P
Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0406, USA. brazhnik@vt.edu
Tyson
John J
JJ
D005075:Biological Evolution; D016934:Caulobacter / Q000166:cytology*; D002453:Cell Cycle / Q000502:physiology*; D005812:Genes, Switch; D008954:Models, Biological; D012441:Saccharomyces cerevisiae / Q000166:cytology*; D013997:Time Factors