Article published in The Atlantic

Modern genetics would not be possible without the humble fruit fly.

In college, I worked briefly in a fruit-fly lab, where I spent most of my time just keeping different fly strains alive. It was not difficult—as anyone with a fruit-fly infestation can tell you—but the repetitive work imprinted itself on my brain. Even today, the way my slightly chubby white cat scrunches when he walks resembles nothing more to me than a third instar fly larva, swollen and ready to metamorphose.

This is to say that I came to First in Fly, a new book about fruit-fly research, with perhaps some special interest. In fact, a popular appreciation of fruit flies has seemed long overdue to me. No single animal has contributed as much to the field of genetics as the ordinary and ubiquitous Drosophila melanogaster. 

These tiny, winged, exoskeleton-ed creatures—so different from us in appearance—have led to research illuminating a surprising amount about the human body: The genes that tell a fruit fly where to sprout its legs are quite similar to the ones that tell our bodies where to sprout limbs. As are the genes that form the pattern of fine hairs on a fly’s wing and the ones that orientate the tiny hairs in our ears. As are the genes that govern a fruit fly’s circadian rhythm and the ones that give us jet lag. And so on. Research into Drosophila has resulted in at least five Nobel Prizes.

First in Fly by Stephanie Elizabeth Mohr is a thorough chronicle of the contributions of these creatures to science over the past century. Mohr herself is a fly scientist at Harvard Medical School, and she knows intimately the life of a “fly pusher.” (The name comes from the act of pushing flies around under a microscope.) She can at times drift too far into molecular biology for a lay reader, but her book is at its best when it conveys both the ingenuity and sheer labor necessary to coax biological secrets out of Drosophila. If you’ve ever looked at a fly and wondered what it could possibly tell you about the workings of the human body, well, it’s not easy for scientists either.... Read more about "Consider the Fruit Fly"

Hormone alerts brain to fat-storage status, but its packaging system goes awry in obesity.

If you’re one of the millions of Americans who’s ever tried to lose weight, you’ve probably heard the old dieting chestnut, “calories in, calories out.”

Calorie restriction does, on the whole, lead to weight loss. But nutrition and energy researchers might rephrase that axiom to more accurately read: “Calories in (a bunch of stuff happens in the body and the brain that influences) calories out.”

A new study published Monday in the journal Developmental Cell uncovers several steps of that complex internal communication system — in fruit flies. 

Yes, fruit flies have fat too. Just not very much.

There’s reason to believe these newly discovered molecular pieces of the obesity puzzle could be important in humans, said Dr. Akhila Rajan, a basic scientist at Fred Hutchinson Cancer Research Center and lead author of the study.

In a previous study conducted at Harvard Medical School, where she completed her postdoctoral fellowship, Rajan and colleagues found that a hormone — leptin — which travels from fat to brain exists in both humans and fruit flies. In fact, the human version of leptin can sub in for the insect version of the hormone in genetically engineered flies.

In obese people, something goes awry with leptin, which acts as a readout of the body’s fat-storage levels. The hormone’s packaging system changes, but it’s not clear exactly where that dysfunction arises. If those details were worked out, it’s possible that fixing leptin’s packaging could be a new therapeutic avenue to battle obesity, Rajan said.

The other pieces of the signaling chain that the researchers identified in their latest study are also largely the same in fruit flies and people. These new pieces include a protein that shuttles the fly leptin across the border of fat cells. Rajan, Harvard developmental biologist Dr. Norbert Perrimon and their colleagues also found that high levels of calcium, triggered during starvation, block leptin’s migration.... Read more about "Fruit fly study IDs missing links in fat-signaling system"