What scientists know so far

Scientists are comparing the genetic sequence of the mouse with the previously completed genetic blueprint of human beings. Here’s what they have learned so far:

? Mice and humans each have about 30,000 genes. They share 99 percent of them, including those that could make a tail.

? More than 90 percent of genes associated with disease are identical in humans and mice, underscoring the value of the latter in laboratory experiments.

? The mouse’s full genetic blueprint contains about 2.5 billion DNA letters, 14 percent fewer than a human’s.

? Comparing the mouse and human genomes has led to the discovery of about 1,200 human genes and 9,000 mouse genes.

? Mice have more genes that control the sense of smell, reproduction and immunity than humans do.