Dispersal of the parental nucleic acid of bacteriophage T4 among its progeny

摘要: The distribution of the parental deoxyribonucleic acid (DNA) passed on from T4 bacteriophages to their offspring has been measured by allowing radioactive decay proceed in first generation progeny phages containing radiophosphorus atoms transferred them highly 32 P-labeled viruses. amount once-transferred radioisotope transferable own second-generation was then at various stages decay, order determine lethal effects produced P disintegrations within those particles which carry atoms. It found that whereas before about half harbored can be once more second progeny, subsequent rapidly reduce radio-isotope one-third initial value. This final third remains transferable, however, even after further extensive allowed take place. Quantitative evaluation observed rate loss transferability with indicates approximately 60% DNA appears aggregates each amounting 15% total complement per phage and remainder is dispersed into small fragments no greater than 0·3% phage. dispersal nucleic does not seem random breakage forces acting course intracellular reproduction. For it isotope among remained unaffected if bacteria infected parent were temporarily exposed chloramphenicol. Under these conditions, synthesis proceeds while formation intact held abeyance until removal antibiotic. Hence viral subject action during its replication, this artificial extension eclipse should have caused a isotope, furthermore, also studied carrying out transfer experiments aliquots decay. fraction twice-transferred decreased same manner as one-transferred label progeny. cycle essentially unchanged, contrast anticipated obtained. must, therefore, reflect an priori division T-even parts are destined large respectively. These results agreement obtained Levinthal (1956) through direct autoradiography.