Mutagenesis and Genetic Toxicology Flashcards
What is genetic toxicology?
Assesses effects of chemical and physical agents on cell DNA and genetic processes
Health impact in somatic cells?
Cancer results in imbalance of oncogene production and tumor suppressor genes (often induced by a mutagenic event)
Health impact in germ cells?
Mendellian genetics associated w/ inherited diseases (i.e. cyctic fibrosis, downs syndrome)
Who first elucidated the structure of DNA as a double-stranded helix?
Watson and Crick
Be able to identify the damages to DNA
See diagram**
Mechanisms of DNA damage?
DNA Toxins:
- Ionizing radiation
- UV light
- Chemicals
- Exogenous agents
General classes of DNA response?
- .) Repair pathways
2. ) Tolerance mechanisms
Types of DNA repair?
- .) Direct reversal of DNA dmg
- ) Base excision repair
- ) Nucleotide excision repair
- ) Double-strand-break repair
- ) Mismatch repair
Mismatch repair?
Repairs normal nucleotides that are mismatched or unpaired (leaves damaged DNA)
- redundant capacity far exceeding the degree of mismatch production
Formation of gene mutations: Somatic cells?
DNA sequence changes
- additions or deletions
- base substitutions and frameshift mutations
Types of mutations?
Base pair substitution
- replacement of one base-pair (G:C) with another (A:T)
Frame shift mutation
Formation of chromosomal alterations: somatic cells?
Structural chromosome aberrations
Chromosomal aberrations?
Microscopic technique typically using CHQ or peripheral human lymphocytes
When does sister chromatid exchanges (SCE) occur?
When reciprocal exchange of segments between two chromatids of a chromosome.
Human population monitoring
- .) Genotoxicity data used for risk assessment
- ) Matching - critical to reduce cofounders in epistudies
- ) Most common assays
