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DNA Mutations and Repair. Chapter 17 pp. 481-. Mutation Rates and Frequency. 1 to 10 mutations per million gametes. Incidence within a group For example: swine flu incidence in the U.S. Causes of Mutations. Spontaneous. Induced. Environmentally Induced DNA changes.
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DNA Mutations and Repair Chapter 17 pp. 481-
Mutation Rates and Frequency 1 to 10 mutations per million gametes Incidence within a group For example: swine flu incidence in the U.S
Causes of Mutations Spontaneous Induced
Intercalating agents • Insert and distort DNA
Radiation (Techa River) Hiroshima (Aug. 6th, 1945)
Thymine Dimers SOS
alklyating Deamination Adds OH
Oxidative radicals • Reactive forms of oxygen can lead to these radicals
THE AMES TEST Salmonella typimurium
AMES TEST • Saccharin • Aflatoxin 2-aminofluorene
DNA Repair: general characteristics • Double stranded DNA • Redundancy of pathways
Types of DNA repair • Mismatch repair • Direct Repair • Base-Excision Repair • Nucleotide Excision Repair
Mismatch repair • Mut H • Recognize GATC hemi-methylation • Mut S • Mut L
DIRECT REVERSAL REPAIR Direct Repair
Xeroderma pigmentosum Autosomal recessive
Hereditary Non-Polyposis Colon Cancer • HNPCC • 15% of all colon cancers
Li-Fraumeni • P-53 mutation