Yahoo! News – Almost human: Completing the sequencing of the human genome is only the beginning. How to figure out what are the significant parts of the data derived, and how to use it? Sequencing the mouse genome may turn out to be the Rosetta Stone for understanding the human genome. “Both genomes have about three billion bases,

only about 3 per cent of which codes for functional genes–the other 97 per cent being “junk DNA”. In the many millions of years since

mice and humans diverged from a common ancestor, much of the important DNA has been conserved, while the “junk” has mutated

freely and is now very different. That means that simply comparing the two genomes will be an efficient way of identifying vital

stretches of DNA, including genes and sequences that regulate gene expression.

Even better, by “knocking out” selected genes in lab mice, we get a good idea of what they do. The equivalent genes in humans should

have very similar functions.”