MICE TAKE THE STRAIN
The Guardian Newsletter Vol 7 No.22 - Summer/Autumn 2001 page 9

For a hundred years, mice have been intensively inbred, artificially
mutated and selected to produce strains with a wide range of
debilitating genetic problems. Generic modification has brought the
total number of strains available to over 2,500.

Strains have been bred that are hugely obese (in 1950); or that have
little or no immune system, thus lacking resistance to infection and
the bacteria to digest food (the nude mouse in 1962 & SCID mouse in
1983). Nude mice are not better models of humane cancer, they are
still mice, but with a depressed immune system, they are certainly
easier to give cancer. Another consequence of mice with a lowered
immune system is that "almost every producer has had to destroy vast
numbers of animals to halt epidemics"

Certain strains are so delicate that sudden noise or vibration can
induce seizures. They could not possibly survive in a natural
environment, and their short lives in captivity have suffering built
in. A procedure developed in 1954, involving the transplant of
ovaries, even managed to bypass the need for mice to survive to
breeding age in order to propagate the strain. As a result, mice
whose suffering is so great that they die young, can still produce
thousands of similarly debilitated offspring to face the same fate.

Over 1.6 million mice were used in Great Britain alone in 1999,
accounting for 60% of all procedures carried out, with the number
rising. This dose not reflect he true waste of life involved in
breeding mice. For example, Lexicon Genetics of Texas "spend 8 months
creating four custom-tailored knockout (lacking specific genes) mice
for each customer." During genetic modification, mice are killed to
harvest eggs and offspring that do not take up the gene are killed.
Data collected in labs by the NAVS shows that even amongst
conventional lab mice, three are killed as surplus for each one that
is actually used.

It is said that "....scientists like mice because they are
physiologically and genetically similar to humans" but there are
fundamental differences between mice and people, including lifespan
and physiology. For example, CF (cystic fibrosis) research led to the
development of genetically modified CF mice. However, one team
admitted that CF mice do not develop the liver problems common in
human CF patients.

Similarly, if a protein called leptin is given to mice with a genetic
mutation leading to obesity, they will lose weight, but such
treatment is unlikely to be effective in humans since obese people
may already have high levels of leptin.

That massively more mice are being used in laboratories that any
other mammalian species (three times as many as rats even) is almost
certainly down to convenience rather than science. Not even the
vivisectors pretend they are the species most like us. Mice are small
and easy to store (twice as many can be squeezed into the same space
as rats), they breed quickly and easily, so there can always be a
full age range in stock. Animal labs routinely overbreed, killing
three times as many mice as surplus as they actually use, simply
because they always want these animals on tap. The vivisectors also
feel they are safer, in public relations terms, to use mice than
monkeys. Consequently, these intelligent, inquisitive animals
probably endure more suffering than any others, whilst researchers
appear to regard them simply as "fuzzy test tubes"



References.

The Rise of the Mouse, Biomedicine's Model Mammal. Science 288 (14th
April 2000): 248-57

Home Office Statistics of Scientific Procedures on Living Animals -
Great Britain 1998.

Nature (1992) 357:31

Peters R.H. et al. (1996). American Journal of Physiology 271: 1074-
1083.

SCRIP 2133/34:23 (May 31st/ June 4th 1996)