Gene Mutation, DNA Repair, and Transposition
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Transcript of Gene Mutation, DNA Repair, and Transposition
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Chapter 14 Lecture
Essentials of Genetics
Gene Mutation, DNA Repair, and Transposition
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14.1 Mutations Are Classified in Various Ways
• Spontaneous and Induced Mutations
• Classification Based on Location of Mutation • Somatic• Germline• Autosomal• X-linked
• Mutations are also classified as dominant versus recessive
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14.1 Mutations Are Classified in Various Ways
• Classification Based on Phenotypic Effects• Loss-of-function
• Gain-of-function• Morphological• Nutritional• Behavioral• Lethal• Conditional
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Classification Based on Type of Molecular Change
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14.2 Spontaneous Mutations Arise from Replication Errors and Base Modifications
• DNA Replication Errors
• Replication Slippage
• Tautomeric Shifts
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14.2 Spontaneous Mutations Arise from Replication Errors and Base Modifications
Depurination and Deamination
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Deamination
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14.2 Spontaneous Mutations Arise from Replication Errors and Base Modifications
Oxidative Damage
Transposons
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14.3 Induced Mutations Arise from DNA Damage Caused by Chemicals and Radiation
Base Analogs:•Compounds that can substitute for purines or pyrimidines during biosynthesis of amino acids.
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15.3 Induced Mutations Arise from DNA Damage Caused by Chemicals and Radiation
Alkylating Agents:• Mustard gas is an example of an alkylating
agent that adds alkyl groups to the purine or pyrimidine of the nucleotide.
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Acridine Dyes and Frameshift Mutations
Intercalating agents
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Acridine Dyes and Frameshift Mutations
Acridine Dyes•Cause frameshift mutations.•These agents form a wedge between purines and pyrimidines of intact DNA.•This contorts the helix and can lead to deletions or insertions.
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Ultraviolet Light
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15.3 Induced Mutations Arise from DNA Damage Caused by Chemicals and Radiation
Ionizing Radiation
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Ionizing Radiation