DNA Mutations and Repair

Chapter 17

Detecting mutations with the AMES test

SUMMARY OF AMES TEST

AMES TEST

• Saccharin

• Aflatoxin

2-aminofluorene

Aflatoxin B1

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

A closer look at mismatch repair

Direct Repair

DIRECT REVERSAL REPAIR

BASE EXCISION REPAIR

BASE EXCISION REPAIR

Nucleotide Excision Repair

Diseases of DNA repair!

Xeroderma pigmentosumAutosomal recessive

Hereditary Non-Polyposis Colon Cancer

• HNPCC

• 15% of all colon cancers

Li-Fraumeni

• P-53 mutation