dna mutations and repair
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DNA Mutations and Repair. Chapter 17 Part 1. Gene Mutations and Repair. Nature of mutations Causes of mutations Study of mutations DNA repair. Nature of Mutations. Chernobyl, April 26 th , 1986. - PowerPoint PPT PresentationTRANSCRIPT
DNA Mutations and RepairChapter 17Part 1
Gene Mutations and Repair Nature of mutations
Causes of mutations
Study of mutations
DNA repair
Chernobyl, April 26th, 1986
Nature of Mutations
Mutation: is defined as an inherited change in genetic information by cell division or individual organisms.
Mutations can be classified into categories.
Categories of mutations
Somatic and germ line
Achondroplasia
Autosomal Dominant
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
Gene Mutations can also be classified by type of mutation
Base Substitutions
Transitions and Transversions
can be
PURINE TO PURINEPURINE TO PYRIMIDINE
PYRIMIDINE TO PURINE
Expanding trinucleotide repeats
Fragile X Syndrome
Pre-mutation
Fragile X syndrome:FMR-1 gene
Strand slippage may cause repeats
Spontaneous: slippage
Phenotypic changes and mutations
Reverse mutationForward mutation
Forward versus Reverse Mutations
Terms associated with PHENOTYPIC effects of mutations on protein structure
redundancyCan be “neutral”
Phenotypic effects can also change function
1 Sullivan, J.P. et al., Department of Pathology, College of Veterinary Medicine, 1998 The University of Georgia, Athens, GA
Gain of Gene Function1
Loss of Gene Function2
Qualtek Molecularlabs Web Site
or
Loss of Function can also occur!
Typically recessive mutations!
Suppressor Mutations is a genetic change that hides the effect of another mutation
Intragenic Suppressor Mutations
Intergenic Mutation
Lethal Mutations
Do you remember something about each type of mutation?