Genetics

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Genetics in the news.
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Genetics in the news.
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Mutations

• are heritable changes in base sequences that
  modify the information content of DNA.

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Wild-type Allelestwo definitions

• General any allele existing at a frequency
  greater than 1 in a natural population,
• Experimental Geneticist the one allele that
  dictates the most commonly found phenotype in a
  population.

• Forward mutation any change that changes a
  wild-type allele to a different allele

A --gt a recessive mutation
b --gt B dominant mutation
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Mutant Classificationsgeneral

• Spontaneous
• Induced

• Morphological
• Nutritional..
• Biochemical
• Regulatory

• Gametic
• Somatic

• Lethal
• Conditional
• i.e. temperature sensitive

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Mutant Classificationsby their effect on DNA

• Substitutions

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Tautomeric Shift point mutations
Spontaneous?
Fig. 14.8
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Mutagenic Agents
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pp. 372
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Mutant Classificationsby their effect on DNA
1 base? 2 base? 3 base? etc.

• deletions and insertions

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Frameshifts
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Mutant Classificationsby their effect on DNA

• inversions

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Trinucleotide Repeat Expansions
FMR1
Fragile X Mental Retardation 1
...GCGCGGCGGTGACGGAGGCGCCGCTGCCAGGGGGCGTGCGGCAGCG.
..
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
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cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
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cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
cgg
gt 230
...
CTGGGCCTCGAAGCGCCCGCAGCCA
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Ames Testtesting for mutagenicity
More mutagenic? Barbecue beef Iceberg
Lettuce Cold Beer
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Section 14.10

• Not responsible for the material
• There will be an extra credit question on the
  test for those of you that have already read the
  material.

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? AAUAAA
enhancer, silencer, core promoter?
?
?
?
?
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5
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TuesdayDNA Science

• PCR,
• Southern Analysis,
• Northern Analysis.

See Assignments Section of Blackboard for Details