Fruit Fly Genes Are Topic of Summer Research

William Stateman '10
William Stateman '10
On the surface, humans and flies may seem to have very different embryonic development; while it takes nine months for one human baby to develop, hundreds of fly eggs can hatch in the incubation period of only 24 hours. But, in both species, the undifferentiated embryo separates at some point to become different segments and appendages to the body. The molecules that trigger these differentiating genes are called morphogens, and each species has hundreds to thousands of them in its genome. Continuing his work on his biochemistry thesis under Professor of Biology Herman Lehman and Visiting Assistant Professor of Biology Danyang Yu, William Stateman ’10 is trying to identify the effects of one specific morphogen on embryos of fruit flies.

In the common fruit fly (Drosophila melanogaster), one of the most important morphogens is called hunchback. Hunchback is released at the presumptive head part of the embryo and designates many of the other areas as differentiated regions; because it is so important, it can be thought of as a master control morphogen. But some parts of the protein molecule cause different functions and, to see which parts are the most important, Stateman will produce fruit fly embryos that are missing a crucial region of this morphogen.

In order to work, hunchback is thought to dimerize, or combine with another copy of itself, and it needs a special structure called a zinc finger in order to do so. If the mutant flies are missing the zinc finger, Stateman hypothesizes, hunchback will not be able to dimerize and, thus, will not be able to function. The mutant fruit flies that Stateman breeds, then, will lack the zinc finger, allowing him to compare these mutant flies with flies that have a working copy of hunchback. Stateman hopes to attribute the differences between the two types of embryos to the lack or presence of normal hunchback. “No one has actually shown in real embryos that, if you cut off a part of the morphogen, the embryo changes in the predicted way,” Stateman said. He hopes he can be the first to do so.

“These results [of the mutant flies] will tell me if these parts of hunchback are important to the regulation of its targets. If the embryos containing hunchback that lack the ability to dimerize are different, then this part of the protein is really necessary for normal development,” Stateman said.

The primary tool that will help Stateman identify the role of hunchback is a technique called fluorescent in situ hybridization, or FISH. When a cell is coding to create a new protein, a copy of the DNA must leave the nucleus. This “carrier pigeon” of protein blueprints is called mRNA (the “m” is for messenger). FISH binds fluorescent probes to only those desired mRNAs or the proteins it produces. So, in a properly-prepared fruit fly, the parts of the organisms that are regulated by hunchback will fluoresce, allowing Stateman to see exactly which parts correlate to the hunchback morphogen. Using this technique, Stateman will hopefully be able to determine the role and function of hunchback in both normal and mutant flies as well as the role of dimerization in the effectiveness of the morphogen.

A recent graduate with a double major in Chinese and biochemistry, Stateman is working on a plan to create a marketing consulting firm in China. He hopes that this firm will aid Chinese companies in attracting American customers and investors.

Stateman graduated from the Cate School in Carpinteria, Calif.
Back to Top