Deoxynucleotides: Models for Studying Mechanisms of Strand Breakage in DNA. II. Thymidine 3'5' Diphosphate

摘要

Strand breaks produced in DNA as a result of irradiation in vivo are discussed. The damage measured as a strand break exists in three different forms immediately after irradiation: (1) actual strand breaks (2) damage which on standing in neutral solution produces a strand break and (3) radiation products which break down only on alkali treatment to cause a strand break. The latter type of damage would never be translated into a strand break in vivo. Since the chemical identities of the strand break types differ and since their time of information will vary, (some being formed only on an alkaline sucrose gradient) care must be taken in (1) assigning yields of strands breaks to in vivo systems and in (2) describing enzymatic strand break repair systems.