title: [Role of cytosine photohydrates in the UV-induced mutagenesis of phage Sd].
abstract: Substitution of H2O for D2O does not affect the rate of UV-inactivation of the extracellular phage Sd, containing double-stranded DNA. However, the yield of plaque-mutants induced by UV-irradiation in D2O is significantly lower, that in H2O. This difference is mostly pronounced at doses greater than 100 erg/mm2. Since the substitution of H2O for D2O selectively decelerate photohydration of pyrimidines (only cytosines in DNA), one could conclude that the formation of cytosine photohydrates in DNA accounts for significant part of UV-induced mutations but it is not an essential reason for UV-inactivation of extracellular phage Sd.
mesh_terms: D003090:Coliphages / Q000528:radiation effects*; D003596:Cytosine / Q000528:radiation effects*; D009154:Mutation; D011831:Radiation Genetics; D014466:Ultraviolet Rays
chemical_list: D003596:Cytosine
vernacular_title: Rol' fotogidratov tsitozina v UF-indutsirovannom mutageneze faga Sd