Why are mice used at King's?
Mice are the most frequently used species at King’s, which is reflective of the case at a national level. Overall, mice and humans have almost exactly the same set of genes. Of the approximately 4,000 genes that have been comparatively studied in humans and mice, less than 10 are found in one species but not in the other. The mouse was the first mammal to have its genome sequenced, leading the way for genetically altered animals.
Other than their genetic similarity, there are a variety of reasons for their popularity. Mice are small and easily maintained without a large space requirement. They have a huge breeding potential, producing large litters (6-8 pups) over a short gestation period (average of 19 – 21 days). A female mouse can have 5 – 10 litters per year, but the number of litters produced by our animals is limited for welfare purposes.
Both normal and genetically altered mice are available in a variety of strains. Mouse strains can broadly be classified as inbred or outbred. New strains of mice can also be produced without the need to complex genetic alteration. Essentially, if mice are bred through sibling pairings for 20 consecutive generations then a new strain of mouse will have been generated. Inbred mice are genetically very similar. One advantage of this is that it helps to increase the reproducibility of experiments. Inbred mice are the most commonly used mice at King’s, particularly C57BL/6 mice. Worldwide and at King’s, C57BL/6 is the most widely used strain for genetically modified mice, helped considerably by their excellent breeding capacity.
Mice are used for a very wide variety of research purposes at King’s, including the study of neurodegeneration, cardiovascular disease, pain, immunology and developmental neurobiology.
A C57BL/6 mouse strain; the most commonly used strain for genetically altered mice