MOLECULAR-BIOLOGICAL APPROACHES TO GENE-E XPRESSION DURING REGENERATION

This paper constitutes a review of the methodical approaches allowing analysis of the mechanisms underlying development and differentiation. Progress in investigation of the mechanisms underlying embryogenesis is related to the discovery of genic families in the Drosophila genome , which are responsible for different periods of embryogenesis. The tr ue revolution in studies of developmental mechanisms began with the ap plication of molecular-genetic methods for analysis of Drosophila muta nt lines. The clarification and analysis of the genes controlling rege neration is one of the most effective paths toward an understanding of the mechanisms underlying regeneration. Na mutations affecting regene ration are, and the development of alternative (i.e., not based on mut ation analysis) methods of discovery of the genes controlling regenera tion is necessary for investigation of the genetic mechanisms of regen eration. The advantages and drawbacks of the two main approaches for d iscovery of the genes controlling regeneration are considered. The fir st approach is based on the production of a bank of sequences expresse d in the regenerating structures and subsequent screening of the bank by the known probes. This approach also involves analysis of the struc ture, function. and expression pattern of the obtained homologs. The s econd approach is based on subtractive hybridization, which allows ide ntification of the genes specifically expressed in the regenerating st ructures. This approach was made it possible to identify, for the firs t time, new genes specifically expressed during lens and retina regene ration in amphibians.