Objective We will use a novel quantitative approach (Lalev, Anaschkova, Russev, Eur.J.Biochem. in press) to study the effects of gamma-irradiation or the different stages of DNA synthesis in eukaryotic cells. We will use two cell lines - Ehrlich-Lettre ascites tumor cells and Friend transformed erythroid cells, that could be regarded as standing at the opposite ends of the spectrum in respect to their ability to control the cell cycle and differentiate.We will follow the kinetics of initiation of the synthesis of both genomic and mitochondrial DNA after exposure to 60Co to obtain information about the mechanism of inhibition of DNA synthesis by gamma-irradiation. An attempt will made to determine the chromatin structure in the regions of initiation of DNA synthesis and attachment to nuclear matrix in norma and after irradiation. To this end nuclei will be digested with micrococcal nuclease and DNAse I, DNA will be additionally digested with restriction enzymes and will be hybridized to in vitro labelled DNA prob and other functional elements. In a parallel series of experiments we will study the repair kinetics of different transcribed and non-transcribed genes after gamma-irradiation. To achieve this we will use the recently developed universal method for determination of the rates of DNA repair of different genes (Russev, Boulikes, Eur.J.Biochem. 204, 267, 1992). Programme(s) IC-PECO/COPERNICUS - Scientific and technological cooperation between the European Community and European non-member countries, 1992- Topic(s) 0501 - CEEC participation in NUCLEAR FISSION SAFETY programme (RADIATION PROTECTION) Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator Rijksuniversiteit Leiden EU contribution No data Address 72,Wassenaarseweg 2300 AL Leiden Netherlands See on map Total cost No data Participants (1) Sort alphabetically Sort by EU Contribution Expand all Collapse all INSTITUTE OF MOLECULAR BIOLOGY - BULGARIAN ACADEMY OF SCIENCES Bulgaria EU contribution No data Address 21,Bld Acad. Bonchev 21 1113 SOFIA See on map Total cost No data