Although the precise evolutionary origin of the mouse and human lineages is still under debate the divergence time of mouse and human lineages is estimated to be approximately 75 Myr. A typical strain of mouse used in biomedical research is a small, slender rodent that has a slightly pointed nose, body covered in fur and a nearly hairless tail with obvious scale rings. The adult mouse weighs about 2/5 to 4/5 ounces. Litters of 5-6 young are born 19-21 days after mating, and mice are sexually mature as early as 6 weeks. Due to their poor eyesight, mice rely more on their hearing and excellent senses of smell, taste and touch for daily life.
With the rediscovery of Mendel's laws of inheritance in 1900, pioneers in the new field of genetics started to apply these principles to create inbred strains of mice. Today the laboratory mouse is considered the preeminent model for human health, building upon its well-established capabilities in which precise manipulation of the genome is routine. Additional advantages are a short generation interval, scores of inbred strains, thousands of directed and spontaneous mutations, embryonic stem cell lines and gene knockout and knockin techniques.
The house mouse (Mus musculus) typically lives in and around homes, farms, and commercial establishments, as well as in open fields. Mice are mainly nocturnal and eat many types of food but prefer seeds and grain. The onset of cold weather each fall in temperate regions is said to cause mice to move into structures in search of shelter and food thus creating pest control issues.
Originally, the Mouse Genome Sequencing Consortium (MGSC) was formed to accelerate efforts to sequence the mouse genome. The Washington University School of Medicine Genome Sequencing Center, the Broad Institute (previously the Whitehead/Massachusetts Institute of Technology Center for Genome Research) in Cambridge, Mass., and the Sanger Centre in the U.K. were the designated genome sequencing centers for this project. In addition to the MGSC effort, other publicly funded groups contributed to sequencing the mouse genome in a initial MGSC goal of 3x coverage of the mouse genome (C57BL/6 strain). This goal was met and exceeded to a final of ~7X coverage. The whole genome analysis of this draft assembly was published in the December 2002 issue of Nature. Since this time, a concerted effort to finish the draft assembly has been underway. The finishing effort was a clone-based effort, primarily distributed to the centers participating in the draft, with Baylor College of Medicine's Human Genome Sequencing Center being added to the finishing effort. The effort was distributed by chromosome, with the Sanger Center finishing chromosomes 2, 4, 11, and X, and the remaining chromosomes being divided amongst the centers in the United States, utilizing clone paths chosen by WUGSC. Clones were finished to very high standards, with an error rate target of less than 1 error per 10,000 bp. WUGSC contributed approximately 1Gb of non-redundant finished sequence with the Broad Institute, Sanger Center, and Baylor's Human Genome Sequencing Center contributing ~675 Mb, 650 Mb, and 125 Mb respectively, with additional minor contributions of less that 50 Mb from several other centers. Funding for the sequence characterization of the mouse genome is being provided by the National Human Genome Research Institute (NHGRI), National Institutes of Health (NIH).