(This post originally appeared in August 2005.)
I can't seem to get fruit flies off my mind.
Some
years ago, a colleague came to my office at the college to ask about
something or other. She carried a box filled with small glass bottles.
"What's
that?" I asked. Fourteen bottles full of fruit flies, Drosophila
melanogaster, the "black-bellied dew lover," newly purchased for student
experiments. Plastic foam stoppers kept the flies in the bottles,
which were otherwise open to the air. A nutrient broth covered the
inside bottom of the bottles. In each bottle several dozen flies crawled
ceaselessly over a web of nylon fibers.
I lifted out the bottles and read the labels. "White." "Yellow." "Wild." "Vestigial." "Ebony." "Dumpy."
"Wild,"
I knew, would be the red-eyed, black-bellied fruit fly found in
nature. The others were mutants, created in the laboratory, cultivated
in great numbers, and used for breeding experiments in genetics and
embryology.
Here was a chance to get to know a famous
experimental animal. "Can I borrow them?" I asked. And so it was that
six bottles full of fruit flies became my companions for a few days of
close observation.
Drosophila mutants have
Seven-Dwarfs sorts of names, generally derived from the appearance of
the mutant under a microscope (anesthetized with a substance called
FlyNap). Who can resist little animals called Dumpy, Curly, Stubble,
Spineless, Wrinkled, Bristle, and Scarlet? The mutants in my bottles
seemed happy enough; indeed, as happy as their wild cousins. I observed
them with a magnifier as they went about their usual fruit-fly
activities, blissfully oblivious to their aberrant eye colors and oddly
shaped wings.
(And I think of them again this week as we dig into our
fly-teeming compost bin.)
