In the December 5 Nature, the Mouse Genome Sequencing Consortium reports the draft sequence of the mouse genome and an initial analysis of its hidden treasures (Nature, 420:520-562, December 5, 2002). It is widely hoped that comparative genomic analysis will enhance our understanding of the human genome and human disease.

The genome sequence was generated from the assembly of over 40 million sequence reads, representing sevenfold coverage, from the C57BL/6J strain (B6) of Mus musculus. The draft contains almost 225,000 contigs, about 96% of the euchromatic genome, amounting to 2.5 Gb (making it 14% smaller than the human genome). There are over half a million orthologous landmark sequences in the two mammalian genomes, allowing the definition of extensive regions of conserved synteny. The mouse genome has increased numbers of lineage-specific repeat sequences, but less ancestral repeats than the human genome. Analysis of repeat sequences indicates that...