Topic 4: Forensic Applications of Multilocus Genotypes

Question 1

how are DNA samples handled for forensic applications of multilocus genotypes?

Answer 1

• rigid procedures for DNA isolation, sample acquisition, and storage
• needs virtually no chance of contamination from another unknown individual, very clearly documented chain of custody

Question 2

in forensic science, what kind of molecular marker do we want?

Answer 2

microsatellites: a molecular marker that exhibits high levels of polymorphism and variability
- which will allows us to easily distinguish a single individual from a population

Question 3

forensics: the more variable a locus is, the __ the probability of observing a specific genotype at that locus

Answer 3

lower! (desirable for forensics)
(allele freq relatively uniformly distributed)

Question 4

what are:
- The Combined DNA Index System (CODIS)
- The Canadian National DNA Data Bank

Answer 4

The Combined DNA Index System (CODIS)
- US DNA dataset (>14mil ppl)
- 20 core u-sat loci required for inclusion

The Canadian National DNA Data Bank
- convicts of serious offences can be ordered to submit DNA samples
- >600,000 Canadians, result in + conviction

Question 5

Forensics: do HW Equil / Gametic Equil matter when picking loci?

Answer 5

• need to be HW equil
• need to be gametic equil (need independent assessment)

Question 6

why is this forensic method not bulletproof?

Answer 6

police integrity (fake evidence)

Question 7

how to verify paternity using microsatellites?

Answer 7

given biparental inheritance

if a child does not possess one allele present in the putative father at EVERY locus, he is not the father