LIFESCI 15 Lecture Notes - Lecture 13: Microsatellite, Allele Frequency
Document Summary
Dna fingerprinting: solve unsolvable crimes, resolve paternity issues, can prove innocence of people unjustly convicted. Dna is a lo(cid:374)g se(cid:395)ue(cid:374)ce of (cid:862)lette(cid:396)s(cid:863) that ca(cid:396)(cid:396)y the i(cid:374)fo of how to build molecules for the body: 99. 9% of our dna is identical. Almost no base sequence variation: different enough to make 3 million different base pairs, due to size of genome. On average, individuals differ in their dna sequence at 0. 1% of their bases: 3 million differences out of 3 billion base pairs. Short tandem repeats (strs: repeating units of 4-5 nucleotides long. For an str locus many alleles (2 or 3 dozen or even more!) exist within the population, but each individual can only have two of them. Comparing str loci: choose 6 features for which individuals vary a lot, co(cid:373)pa(cid:396)e dna sa(cid:373)ple fo(cid:396) those 6 featu(cid:396)es. If they a(cid:396)e the sa(cid:373)e at all of the(cid:373) : the samples came from the same individuals.
