AGB 121: Principles of Animal Genetics and Population Genetics (2+1)

POST REPLICATION RECOMBINATION REPAIR

• This type of dark repair involves both replication and recombination.
• When DNA molecules containing thymine dimers are replicated, gaps are formed in the nascent strand because DNA polymerase cannot use distorted segments as templates for DNA synthesis.
• This results in progeny double helices with thymine dimers in one strand and gaps in the complementary strand.
• If these two sister chromosomes recombine, dimers and gaps end up in one chromosome and the intact, undamaged segments end up in the other chromosome, the later will be functional and produce a viable cell.