Transcript Diapositivo 1

Spontaneous Damage to DNA
Examples of DNA Damage Induced by Radiation
and Chemicals
Examples of DNA Damage Induced by
Radiation and Chemicals
Direct Repair of Thymine Dimers
Not in humans
A metiltransferase é gasta nesta reacção
Base-Excision Repair
Nucleotide-Excision Repair of Thymine Dimers
Xeroderma pigmentosum
•Autosomal recessive mutations in several complementation groups
•Extreme sensitivity to sunlight
•Predisposition to skin cancer (mean age of skin cancer = 8 yrs vs. 60
for normal population)
Nucleotide excision repair - Energéticamente ineficiente
Mismatch Repair in E. coli
Teste de Ames para agentes mutagenicos