The "Red Queen" Gene: An Excerpt from Jacob's Ladder: The History of the Human Genome, by Henry Gee
Nursery rhymes can be unspeakably violent. Recall, for example, the
three unfortunate mice who, as well as being blind, had their tails
docked by a sadistic, knife–wielding peasant. The
real–life, adults–only version of this tale features a
newborn mouse, seemingly perfect in every way except that the front
end of its body is oddly truncated, ending in a small mound crowned
by two tiny ears. This mouse is certainly blind, since not only does
it have no eyes, it also has no head. It looks as cleanly
decapitated as if by the farmer's wife of folklore. The mouse was
one of four born without a head, as a result of a mutation in a
regulatory gene called Lim1. With no mouth or nose to breathe
through, [it] died very soon after its birth. More than a hundred
other headless mice foetuses did not get as far as being born.
The experiments in which these mice were created were part of an
effort to understand the activities of Lim1, one of an increasingly
well–documented cadre of regulatory genes whose role it is to
ensure that every part of the body develops in the place it should.
When such genes are mutated, the result can be as monstrous as
anything from nursery folklore.
Jacob’s Ladder: The History of the Human Genome
W. W. Norton, $25.95