Population Variation and Forensic Genetics

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Population Variation and Forensic Genetics

• Population Variation
• PCR
• Human Forensics
• Microbial Forensics

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Questions to think about.

• Back to the Fundamentals
• How are non-coding sequences inherited?
• What type of alleles do you find at non-coding
  loci?
• How are new alleles of non-coding loci formed?

Think about these topics as we go through the
lecture and come back to them as you go over the
lecture material and practice problem solving.
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Large Scale Eukaryotic Chromosome Structure
Eukaryotic Genomes
Unique Sequence
Repetitive Sequence
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The Human GenomeSequence Variation

• Repeat Loci
• Micro-satellites (STRs) (lt10bp, CGn)
• Mini-satellites (VNTRs) (10bplt length lt100bp)
• Sequence Polymorphisms
• Coding and Non-Coding Point Mutations (SNPs)
• Structural Variation
• Duplications, Inversions, Deletions

Allelic Frequency vs Genotypic Frequency
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Human Population Nucleotide VariationA
Micro-satellite example
Based on Rosenberg et al. (2003)
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Polymerase Chain Reaction (PCR)
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Forensic Genetics Timeline
Jobling and Gill (2004) Nature Reviews Genetics
5739-751
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Forensic GeneticsUseful Genetic Loci
Jobling and Gill (2004) Nature Reviews Genetics
5739-751
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STR and VNTR Typing PCR Amplification of Repeat
Loci
Molecular Biology of the Cell, 4th Edition, pg511
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STR and VNTR TypingMendelian Inheritance of
Repeat Loci
Repeats
Parents
Progeny
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Typing a Forensic Sample
Molecular Biology of the Cell, 4th Edition, pg511
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Forensic STR Profile ComparisonHow Many Loci
are Needed?
Nine Repeat Loci and Sex
What is a probability match and what does it mean?
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National DNA Databases
PBS Nova Clip
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Microbial ForensicsBascillus anthracis

• Track origin of pathogen
• Relationships between strains
• Transmission route

Cutaneous Anthrax
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vrrA VNTR Locus
Jackson et al. 1997
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VNTR Typing the vrrA Locus
Jackson et al. 1998
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Microbial Forensics Case Study1979 Sverdlosk
Outbreak
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1979 Sverdlosk OutbreakvrrA Typing of Victims
Jackson et al. 1998
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Modern Microbial ForensicsTyping Several VNTR
Loci Simultaneously

Keim et al. 2000
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Microbial Forensic DatabaseHigh Through-put
Typing of 45 Anthrax Strains
Keim et al. 2000
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The Genetics Book Club..
Further Reading Jobling and Gill (2004) Encoded
Evidence DNA in Forensic Analysis. Nature
Reviews Genetics 5739-749. Forensic Reality and
Practical Experience of DNA Typing Update Ron M,
Fourney, National DNA Data Bank of
Canada Anthrax The investigation of a deadly
outbreak. By Jeanne Guillemin Jackson et al.
(1998) PCR analysis of tissue samples from the
1979 Sverdlorsk anthrax victims The Presence of
multiple Bascillus anthracis strains in different
victims. PNAS 95 1224-1229. Keim et al. (2000)
Multiple-Locus Variable-Number Tandem Repeat
Analysis Reveals Genetic Relationships with
Bacillus anthracis. J. of Bacteriology 182
2928-2936. Keim et al. (2001) Molecular
investigation of the Aum Shinrikyo Anthrax
Release in Kameido, Japan. J. Clinical
Microbiol. 39 4566-4567. Hoffmaster et al.
(2002) Molecular Subtyping of Bacillus anthracis
and the 2001 Bioterrorism-Associated Anthrax
Outbreak, United States. Emerging Infectious
Disease 8 1111-1116
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Genetics Movie Night..
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Pharmacogenetics, Geographical Ancestry and
MedicineRace Based Medicine?
Required Reading Race in a Bottle by Jonathan
Kahn, Scientific American