CASE 3 YOU, FROM A TO T: YOUR PERSONAL GENOME

Sequencing of mitochondrial DNA reveals mitochondrial haplotypes analogous to those in the Y chromosome. As in the Y chromosome, mutations in mitochondrial DNA accumulate through time, and each mitochondrial haplotype remains intact through successive generations because no recombination between mitochondrial genomes takes place. This means that mitochondrial DNA can be used to trace ancestry and population history, much as described previously for the Y chromosome. The mitochondrial DNA is actually more informative than Y-chromosomal DNA because it shows substantially more genetic variation so its ancestry can be tracked on a finer scale.

The use of mitochondrial DNA to trace human origins and migration is discussed in greater detail in Chapter 24. As with the Y chromosome, your personal mitochondrial genome includes information about its origin. If you want to learn about your mitochondrial DNA, you can send a tissue sample to any of a number of direct-to-consumer genotyping services that will, for a fee, analyze the DNA and provide you with a report.