A Proposed Solution to the Historic Puzzle of Chargaff's Second Parity Rule

摘要

Chargaff ’s first parity rule for the contents of the four nucleotides in DNA is easily understood based on thedouble-stranded DNA structure. However, the second parity rule, based on similar nucleotide relationships in singlestrandedDNA, has been a puzzle in molecular biology, because it is impossible to imagine how pairs of G and C, and Aand T are formed in the single DNA strand. In the present study, Chargaff’s second parity rule can be solved based on nucleotidecontents and the correlation between the two strands in double-stranded DNA.