forensic biology by richard li
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Chapter 19: Y-STR Profiling and Gender Typing. Forensic Biology by Richard Li. Basics. Y chromosome inherited by the father Unique to males Y-STR Sexual assault investigations w/ male suspects Mixtures Number of perpetrators Paternal lineage can be est. Missing person cases. Basics. - PowerPoint PPT PresentationTRANSCRIPT
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Chapter 19: Y-STR Profiling and Gender Typing
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Y chromosome inherited by the father Unique to males Y-STR
Sexual assault investigations w/ male suspects
Mixtures Number of perpetrators Paternal lineage can be est. Missing person cases
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Disadvantages of Y-STR Discriminating power are low Product rule does not apply Cannot distinguish individuals with the
same paternal lineage
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60 million base pairsTwo regions:
Psuedo-Autosomal Region (PAR) Male Specific Region Y (MSY)
Repetitive elements: STRs Alu LINE SNPs
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400 STR loci have been identified Majority on long arm (60%)
22% on short arm Core repeat sizes:
9% dimeric, 39% trimeric, 45% tetrameric, 9% pentameric, 1% hexameric
Haplotype- collection of alleles that are linked
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European Minimal Haplotype (EMH) 1997 Core set of nine loci DYS19, DYS385a/b, DYS389I, DYS389II, DYS390,
DYS391, DY5392, DY5393
U.S. Haplotype 2003 SWGDAM EMH set plus tow additional loci: DYS438 &
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Y-STR in forensic casework started in Europe
Office of Chief Medical Examiner in NYC
Facilitated by commercially available kits Y-PLEX 6
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Victim identification & Sexual assault cases
Amelogenin (AMEL) marker usedAMELX & AMELYAMELY null mutations
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