L20 Genetic Markers in Forensics Flashcards Preview

Evolutionary Genetics > L20 Genetic Markers in Forensics > Flashcards

Flashcards in L20 Genetic Markers in Forensics Deck (8)
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1
Q

Short tandem repeat loci

A
  • consist of tandem repeats of a DNA motif of 1 to 6 bp
  • also referred to as microsatellites
  • widely used as genetic markers in population genetics and in forensics where neutrality is often assumed
2
Q

STRs in human disease

A
  • can cause huntington disease, motor neuron disease and fragile X syndrome
  • age of disease onset and/or severity of disease often depend on repeat length: longer is worse
3
Q

STR mutation

A

see onenote

  • strand slippage
  • stepwise mutation model
  • mutation rates are highly variable across loci and can depend on may factors
4
Q

Typing STR loci using capillary gel electrophoresis

A
  1. extraction of DNA
  2. amplification via PCR
  3. separation of PCR products (allele) according to length
  4. detection via fluorescent dyes
5
Q

Some genotyping issues

A

see onenote

  • microvariants
  • silent/null alleles
  • stutter
  • pull-up peaks
  • copy number variants
6
Q

Contamination

A

two sources of contamination:

  1. by environmental DNA before the sample is collected
  2. subsequent to sample collection e.g. in the lab
7
Q

How do we assess reliability of scientific evidence?

A

Can we evaluate the evidence in a way that is comprehensible to courts and not unfair to defendants?

8
Q

How do we assess reliability of scientific evidence?

A

Can we evaluate the evidence in a way that is comprehensible to courts and not unfair to defendants?