We identified your fingerprint at one locus, D1S80, with 25
known alleles. Within the human genome, many
short tandem repeat (STR) regions have been identified. Tens of thousands of STR regions exist within
exons and introns of various genes.
About half of these are highly polymorphic, that is, the number of STRs
is highly variable. STRs consist of a
three to seven base pair motif that is repeated a variable number of times in a
also the following three STRs, used most frequently by crime labs, and answer
the following questions about your experiment and about crime lab DNA
fingerprinting. The first one (CSF1PO)
is located on chromosome arm 5q and the number of repeats varies between 6 and
15 (i.e. there are ten known alleles).
These alleles lie within a proto-oncogene. A second STR (TPOX) lies within the thyroid
peroxidase gene on chromosome arm 2p and the repeat number varies between 6 and
12 repeats (i.e. there are seven known alleles). Finally, a third STR site (THO1) is located
on 11p and the number of repeats varies between 5 and 11 (but also includes a
9.3 repeat allele caused by a truncated repeat, for 8 known alleles).
many different allelic combinations (i.e. genotypes) could exist in
the human population for the D1S80 locus?
(Consider the number of different homozygous and heterozygous
genotypes that could occur with the 25 known alleles.) Show
your calculations here and on the remaining problems!
many different allelic combinations could exist in the human populations
each combination occurred with equal frequency, what is the probability
that a randomly-chosen person would carry the same genotype as you at
DNA fingerprinting, crime labs identify a person’s DNA fingerprint at each
of the 3 loci: CSF1PO, TPOX and THO1.
If each combination occurred with equal frequency, what is the
probability that a randomly-chosen person would carry the same genotype as
you at all three loci?
many people in the would be expected to share a particular genotype for
these 3 loci
the entire world (population 7 billion)?
North Carolina (population 10 million)?