The hedgehog signaling cascade system: Evolution and functional dynamics

Abstract

Here, the results we obtained in the analysis of the parametric robustness of the Hh signaling cascade and molecular gene evolution are compared. Emphasis is on the molecular evolution events that match the corresponding divergence of the major Bilateria taxonomic types. It is demonstrated that positive selection is characteristic of the genes that encode proteins of the Hh-cascade whose function is related to the molecular morphogenesis mechanisms and matches with the divergence events of the Bilateria types. It was found that the gene products of the Hh-cascade that are subject to positive selection define the kinetic parameters whose change produces the greatest shift in the dynamics of the Hh-cascade. The evolutionary implications for the phenomenon are discussed. © Springer 2008.