DNA Mutations and Repair

1. DNA Mutations and Repair Chapter 17 Part 1

2. Gene Mutations and Repair • Nature of mutations • Causes of mutations • Study of mutations • DNA repair

3. Nature of Mutations Chernobyl, April 26th, 1986

4. Mutation: is defined as an inherited change in genetic information by cell division or individual organisms.

5. Mutations can be classified into categories. Categories of mutations

6. Somatic and germ line

7. Achondroplasia Autosomal Dominant

8. Gene Mutations can also be classified by type of mutation • 1. Base Substitutions □2. Insertions and deletions • 3. Frameshift mutations • 4. Expanding trinuleotide repeats Lead to

9. Gene Mutations can also be classified by type of mutation • Base Substitutions Transitions and Transversions can be

10. PURINE TO PYRIMIDINEPYRIMIDINE TO PURINE PURINE TO PURINE

11. Expanding trinucleotide repeats

12. Fragile X Syndrome Pre-mutation

13. Fragile X syndrome:FMR-1 gene

15. Strand slippage may cause repeats

16. Spontaneous: slippage

17. Phenotypic changes and mutations

18. Reverse mutation Forward mutation

19. Forward versus Reverse Mutations

20. Terms associated with PHENOTYPIC effects of mutations on protein structure Can be “neutral” redundancy

21. Phenotypic effects can also change function Gain of Gene Function1 Loss of Gene Function2 1 Sullivan, J.P. et al., Department of Pathology, College of Veterinary Medicine, 1998 The University of Georgia, Athens, GA or Qualtek Molecularlabs Web Site

22. Loss of Function can also occur! Typically recessive mutations!

23. Suppressor Mutations is a genetic change that hides the effect of another mutation

24. Intragenic Suppressor Mutations

25. Intergenic Mutation

26. Lethal Mutations

27. Do you remember something about each type of mutation?