Mice
Mice are the most commonly used vertebrate species, popular because of their availability, size, low cost, ease of handling, and fast reproduction rate.
They are widely considered to be the prime model of inherited human disease and share 99% of their genes with humans. With the advent of genetic engineering technology, genetically modified mice can be generated to order and can cost hundreds of dollars each.
Transgenic animal production consists of injecting each construct into 300–350 eggs, typically representing three days' work. Twenty to fifty mice will normally be born from this number of injected eggs. These animals are screened for the presence of the transgene by a polymerase chain reaction genotyping assay. The number of transgenic animals typically varies from two to eight.
Chimeric mouse production consists of injecting embryonic stem cells provided by the investigator into 150–175 blastocysts, representing three days of work. Thirty to fifty live mice are normally born from this number of injected blastocysts. Normally, the skin color of the mice from which the host blastocysts are derived is different from that of the strain used to produce the embryonic stem cells. Typically two to six mice will have skin and hair with greater than seventy percent ES cell contribution, indicating a good chance for embryonic stem cell contribution to the germline.
Read more about this topic: Animal Testing On Rodents
Famous quotes containing the word mice:
“will your eyes lie in wait,
little field mice nestling on their paws?
Perhaps they will say nothing,
perhaps they will be dark and leaden,
having played their own game
somewhere else....”
—Anne Sexton (1928–1974)
“It is as when a migrating army of mice girdles a forest of pines. The chopper fells trees from the same motive that the mouse gnaws them,—to get his living. You tell me that he has a more interesting family than the mouse. That is as it happens.”
—Henry David Thoreau (1817–1862)
“Paradise endangered: garden snakes and mice are appearing in the shadowy corners of Dutch Old Master paintings.”
—Mason Cooley (b. 1927)