Chapter 21, Problem 18P

The following figure shows the FBI-style analysis of the genomic DNA of 10 people (1–10), and also of hair found at a crime scene left by the murderer [***]. This analysis involves the PCR amplification of SSR loci, each from a different (nonhomologous) chromosome. The PCR primers are for each SSR locus are labeled with a unique fluorescent molecule. Some bands are thicker because relatively more of the corresponding PCR product was obtained. The figure has dots aligned on both sides to help you find the crucial bands; it will help to use a straight-edge as a guide. The numbers at right are the total number of copies of the SSR locus among the population of 11 samples.

a.	Are any of individuals 1–10 the murderer? If so, which one?
b.	Are any of the loci on the X chromosome? If so, identify this (these) locus (loci) by color.
c.	Are any of the loci on the Y chromosome? If so, identify this (these) locus (loci) by color.
d.	Are any of individuals 1–10 probable relatives of the murderer? If so, identify this person and describe the degree of relationship to the criminal.
e.	One of individuals 1–10 is aneuploid. Write the identity of this person, their sex (M or F), the type of aneuploidy involved, whether the nondisjunction occurred in the mother or father of this person or you can’t tell, and whether the nondisjunction occurred during meiosis I or meiosis II or that you can’t tell.
f.	What is the probability that any random male in the United States would share the same genotype as the murderer (the match probability)? Assume that all 11 DNA samples analyzed in the diagram are together representative of the U.S. population as a whole. Show what numbers you would multiply to do this calculation.
g.	Explain why the assumption in part (f) that the sample is representative cannot be completely accurate. How might the inaccuracy of this assumption affect the match probability?