The mouse genome sequence

The mouse is the leading mammalian model organism for the study of genetics. Its genome consists of about 2500 Mb of DNA and contains about 30 000 genes, virtually all of which have close homologs in the human genome. Comparison of the mouse with other mammalian genomes indicates that it is not only the coding sequences of genes that have been maintained in evolution; putative conserved control elements can be identified by aligning multiple genomes. The DNA of the mouse (and rat) is accumulating changes at a much more rapid rate than the human genome. Base substitutions in neutral sequences have accumulated about twice as fast in the mouse when compared to humans, since their last common ancestor 75 million years ago. Furthermore, transposable elements have been more active in the rodent lineage, and there have been more chromosomal rearrangements that alter long-range relationships between genes.

Keywords: genome evolution; orthology; gene regulation; sequence; repetitive DNA; mutations