Monday, August 29, 2005

FlyNap

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 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 think of them again this week as we put our fly-teeming compost bin to sleep.