The mouse has become only the second mammal after the human to have its entire genome laid bare. Knowledge of the full mouse genome will now allow scientists to neatly separate the biology humans share with mice from biology found in one species only. This will enhance scientists’ ability to select the genes most applicable to human disease when developing mouse models.
The findings are reported in a landmark publication describing the finished mouse genome sequence in the May 26, 2009 issue of PLoS Biology.
The sequencing project began in 1999 using DNA from one strain of laboratory mouse. Teams from around the world completed the marathon task of sequencing the mouse genome, passing on their new data to Dr Deanna Church of the National Center for Biotechnology Information in Maryland, who neatly pieced it all together. It was then up to Dr Leo Goodstadt and Professor Chris Ponting at the MRC Functional Genomics Unit, University of Oxford, to figure out which genes which genes were present as single copies in the genomes of both mouse and human, and are most likely to have the same function in both species.
The mouse, Mus musculus, is the animal model most often used to better understand human diseases and how they develop. Commenting on completion of the sequencing project, Professor Ponting said:
"Completion of the genome is extremely important in helping us to identify the genes that underpin biology that is the same across all mammals, and to separate the genes in common from those that make humans and mice so different from one another." By filling in the gaps left by the previous version of the mouse genome, a vast treasury of new genes has been revealed. Many of these newly discovered genes are evolving at an unusually rapid pace.’’
The genome described in the PLoS Biology paper provides a more complete picture than past attempts to sequence the genome because it includes many more mouse-specific stretches than previously had been available. Dr Leo Goodstadt explained:
"In retrospect, our previous picture of the mouse genome was incomplete. Only when all the missing pieces of the genomic puzzle had been filled in did we realize that we had been missing large numbers of genes found only in mice, and not in humans."
Dr Deanna Church, staff scientist at the National Center for Biotechnology Information at the US National Institutes of Health, added:
“The painstaking work of the genome centers in completing it has been well worthwhile. The new findings will allow us to dismiss some commonly held misconceptions and, more importantly, to reveal many previously hidden secrets of mouse biology”.
Dr Goodstadt concluded:
‘‘Despite 90 million years of independent evolution the mouse remains an excellent model for many human conditions and so is crucial to the study of human disease and mammalian development. An improved understanding of the mouse genome, and so mouse biology, will enhance the utility of the mouse as a model for human disease.’’
Source: Medical Research Council