Much learned from lowly drosophila

I am told that some of my jokes do not translate well. Here is one: one fly tells another, “I must be very important, for wherever I go, people are clapping their hands.” Translation: the fly thinks it is important but in reality, the pest is a pure nuisance. Everywhere it goes (or rather flies), people want to put an end to its annoying presence, to hit and kill it mid-flight with one quick handclap.

The joke is funny because we all know someone who believes himself to be important, while he is not. This gap between illusion and reality creates tension, and once realization sinks, laughter follows.

I am in Orlando, Florida, sitting in a lecture hall with thousands of other doctors. On Monday at about 9 a.m., Dr. Thomas Chi is stepping up to the podium. The lecture hall is so quiet that you can hear a fly, but there is not a single fly in the air and no hand-clapping, just dead silence.

I look around and recognize that some of my colleagues are half asleep, while others are half awake. Not me! Reminding myself of the fly joke, I prepare myself for an entertaining talk on “Animal Models in Kidney Stone Disease,” a lecture spiced by a discussion about no other than the drosophila.

About the drosophila, I would tell you the following: It is a small, mildly hairy, yellow fly with flimsy, spotted wings and big, bright red, expressionless eyes. Under proper magnification, it is quite scary but in reality it is only a few millimeters long.

It belongs to a highly reproductive and diverse family whose members are spread everywhere in the world: swamps, rainforests, deserts and cities. You have seen it around, I am sure, hovering over overripe and rotten fruit. You might have recognized it, as most people do, as the simple, common fruit fly.

Perhaps simple, perhaps common, but it is the unassuming drosophila that gained utmost popularity among scientists as one of the ideal model organisms for research purposes.

It is for good reasons. It is small and therefore requires only little lab space; it cost little and is easy to raise in the lab; it multiplies quickly; it has a short life-span and is prone to mutations (changes in its genetic material); it has few, large chromosomes that can be easily studied. And finally, its use as an animal model evokes little emotional response. To put it mildly, nobody cares about the fate of a drosophila.

Pay close attention to the drosophila, and you too may win a Nobel prize. Thomas Hunt Morgan did. At the dawn of the twentieth century, while studying the genetics of the drosophila, Morgan discovered a mutation resulting in a change in the eye color of the drosophila.

These changes appeared in a rather peculiar manner. In Morgan’s words, “a white eyed father transmits the character (of white eyes) to about one fourth of his grandsons but to none of his granddaughters.”

In those early days, DNA was not yet discovered, but Morgan understood that there is a factor, some form of genetic material that determines the eye color of the drosophila and is attached to a chromosome that determines the gender of the offspring.

In his famous fly room at Columbia University, performing this and other experiments, Morgan demonstrated that genes are carried on chromosomes. It was his work on the drosophila fly that laid the foundation for modern genetics.

About a century later, on a hot, humid day in Orlando, Dr. Thomas Chi is giving a lecture. He tells us that he is using the drosophila fly as a model in his research of kidney stones.

He reports that the fly has rudimentary kidneys that are similar in structure and function to that of the human nephron (the basic functional unit of the human kidney) and that some models of the drosophila form tiny kidney stones, making it an excellent animal model for the study of kidney stones.

Suddenly, in my mind, the simple, common, unimportant drosophila is not simple, or common, nor is it unimportant. I think: in an attempt to make sense of the world, we draw circles around ourselves, trying to include what seems important, and to push away all that seems unimportant. What if what seems simple carries the keys to a better knowledge of ourselves? What if the ones who seem unimportant are the ones that can help us to better understand our lives?

Nowadays, I am careful not to judge anything, anyone as being unimportant. And when I am facing a nuisance, I take a deep breath and I think twice before I clap my hands together.

Editor’s note: Dr. Shahar Madjar is a urologist working in several locations in the Upper Peninsula. Contact him at or at