Faculty Research in the News
They Rely on the Fly
Peter Andolfatto, ecology and evolutionary biology and the Lewis-Sigler Institute for Integrative Genomics Only a small portion of the genome is made up of genes that become proteins. The other 82 percent of the fruit fly’s DNA (98 percent in humans) control how and where genes are expressed. Studies using the fruit fly by Andolfatto and others were among the first to show that portions of this so-called “junk” DNA have important functions. This is now being confirmed in the human genome. By sequencing the genomes of fruit flies found in nature, rather than those raised in the lab, Andolfatto studies how the genome is shaped by adaptive evolution.
Thomas Gregor, physics and the Lewis-Sigler Institute for Integrative Genomics While other scientists study how the fertilized egg creates a body plan of its future self in the first few hours of development, “we are now putting a quantitative, physics layer on top,” says Gregor — measuring the molecules in live embryos to determine how and why the fly’s development is so precise and reproducible. Using special microscopes and other tools developed in his laboratory to measure these molecules, Gregor has shown that there is much more precision in the early stages of embryo development than previously thought.
Elizabeth Gavis, molecular biology Gavis seeks to understand how the pattern of the embryo is set up during development of the egg and early embryo. Her lab has developed a system to fluorescently label molecules to watch their movements in live eggs and embryos. She has shown that the asymmetric placement of these molecules tells the fruit fly which end will turn into the head and which will become the tail end. Some of the same molecules are needed for fertility in mammals.
Paul Schedl, molecular biology How are the 6 billion base pairs of the human genome (about 2 meters of DNA if stretched end to end) packed into a space of 6 micrometers? And how does the cell access this genomic information to express genes? The answer: DNA is combined with proteins to form a structure called chromatin, and different chromatin parts are organized into open and closed sections for ease of use. Schedl studies elements of fruit-fly chromatin that arrange genes into open or closed sections or switch them between the two.
Gertrud M. Schüpbach, molecular biology Fertilization of the fruit-fly egg kicks off the complicated process of forming an embryo. It turns out that much of the information and some of the building blocks needed for the embryo to develop are placed in the eggs when they are being made in the ovaries, rather than coming from the newly formed embryo genome. Schüpbach studies how this happens.