This year's Nobel Prize in Physiology or Medicine was awarded to Oliver Smithies, Martin J. Evans, and Mario R. Capecchi "for their discoveries of principles for introducing specific gene modifications in mice by the use of embryonic stem cells."Sounds pretty boring huh? Well, it's not. It changed biomedical research forever.
Before this work, which began in the 1980s, mice were used to study human biology and disease, but luck played a big role. Random mutations would sometimes result in a mouse that showed some kind of abnormality that mimicked a human condition--a tendency for obesity or cancer, for example.
Researchers could increase the rate of mutation with chemicals or radiation, but they couldn't control where the mutation would occur...until 1989. That's when gene targeting began, and this is how it works. Now scientists can introduce specific mutations into specific genes. What's more, they can control when and where the mutations are expressed. They can also inactivate a gene completely in what are called "knock-out" mice. What better way to determine the function of a gene than to inactivate it?
By now, thousands of mouse genes have been knocked out, and hundreds of new mouse models for human diseases have been created. The mouse genome has about 30,000 genes, and the plan is to knock them all out. In doing so, we can learn the function of each mouse gene, 90% of which have human counterparts.
So here's to the Nobel laboratory mouse. What a knockout!
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