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A new type of laboratory mouse with genetic diversity is on the verge of being bred, according to the online edition of nature.

It took scientists nearly a century to finish breeding the first experimental mice. Early laboratory mice only carried part of the genetic diversity of wild mice. Today, there are hundreds of varieties of laboratory mice, but they have very few traits with human genetic characteristics, which has great limitations on the study of genes that cause human diseases. To change that, the U.S. department of energy's oak ridge national laboratory began a research program in 2005 called collaborative hybridization, which selects and breeds new types of laboratory mice with genetic diversity.

The project has created a full 30 inbred mouse families by selecting inbreeding methods and crossing them with wild species. The differences between the new mice and the ones currently in use are significant, from changes in coat color to differences in tail length, providing clues to genes that fight infection.

In addition, the researchers tested about 66 inbred species that were susceptible to aspergillus fumigatus, a soil fungus that causes respiratory diseases in humans. It turns out that the mice can live between four and 28 days after infection. Based on the genetic information of the new varieties and the sequencing of the genomes of the eight original varieties, the researchers mapped the differences in genomic regions that contained a few genes over time. Researchers are also using the same approach to look for genes that are present in streptococcus pneumoniae resistant to klebsiella.

The cooperative crossbreeding program, which is working with the university of north Carolina, aims to produce several new pairs of lab mice by the end of this year and 100 by 2012.
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