LAUSR

Little is known about the genetic mechanisms underlying high regenerative capacity of fishes, amphibians, reptiles in comparison with birds and mammals. According to the current opinion, the difference in their regenerative capacity rate is a result of genetic network restructuring within virtually the same set of genes. We assumed that this difference could be also caused by loss of significant genes-regulators of regeneration in evolution. In the present work, we propose a bioinformatics approach aimed at system search for such genes. Having applied the approach, we succeeded to identify several genes exclusive to fishes, amphibians, reptiles and then to pick out genes demonstrating increased expression in blastema and wound epithelium during tail and hind limb bud regeneration in the model object Xenopus laevis tadpole. We report here that one of the revealed genes encodes transmembrane protein, which regulates body appendages regeneration along with telencephalic and eye development through binding to FGFR4 and modulating its activity. Consequently, we named this protein c-Answer for cold-blooded Animals specific wound epithelium receptor-binding protein. In our point of view, loss of c-Answer in evolution that led to decrease in regenerative capacity rate in birds and mammals was supported by natural selection due to its possible favorable effect on the progressive forebrain development.