HomeNewsThe 2009 Early Career Scientists: U-Z


The 2009 Early Career Scientists: U-Z


Meet the 2009 Early Career Scientists.

Sinisa UrbanSinisa Urban
The Johns Hopkins University School of Medicine

Credit: ©2009 Rosanna Baker

Communication between cells involves the release of a signal by one cell and its interpretation by another. Sinisa Urban has discovered an ancient family of enzymes that initiate cellular discourse in some of the “talking” cells. These enzymes, called rhomboids, snip apart proteins embedded in the cell membrane, freeing them to send their signals. Urban, who is at Johns Hopkins University, studies the biochemical mechanism of rhomboid action and its biological function in a diverse range of organisms, from humans to bacteria. He recently has shown that, in addition to their role in cellular communication, rhomboids help the parasites that cause malaria invade cells and help dysentery-causing amoebas evade the immune systems of their hosts. He is now expanding his studies to encompass rhomboids' role in other human diseases.

Amy J. WagersAmy J. Wagers
Harvard Medical School

Credit: ©2009 Robert Bachrach

As she completed graduate studies in immunology, Amy Wagers learned she was a match for a person who needed a bone marrow transplant. She devoured reading materials describing the procedure, eager to learn about how her cells could help the anonymous patient. In the end, her marrow wasn't needed, but the experience helped her decide to become a stem cell biologist. Today, she studies blood-forming and muscle-forming stem cells in her lab at the Joslin Diabetes Center and Department of Stem Cell and Regenerative Biology at Harvard Medical School, with an eye toward treating diseases such as cancer, anemia, muscular dystrophy, and diabetes. Her work suggests that defects in aging stem cells may be reversible, and she's established in mice the feasibility of stem cell therapy for treating degenerative muscle disease.

John B. WallingfordJohn B. Wallingford
University of Texas at Austin

Credit: ©2009 Sasha Haagensen

John Wallingford's obsession with morphogenesis—how tissues, organs, and organisms develop their shapes—began as an undergraduate when he manipulated frog embryos and watched them develop in a dish of pond water. He later found that activating a single gene in the embryos triggers a series of shape-shifting events that curl a flat sheet of cells into a closed neural tube. This tube later develops into the spinal cord and brain. Improper closure of the neural tube leads to birth defects, such as spina bifida. Now Wallingford is expanding his research program at the University of Texas at Austin to use both frogs and mice to study how genetic information is translated into the forces that move tissues during development.

Rachel I. WilsonRachel I. Wilson
Harvard Medical School

Credit: ©2009 Graham Ramsay

In an essay describing research that won her the 2007 Eppendorf & Science Prize for Neurobiology, Rachel Wilson wrote, “The air around us is full of chemical signals—plumes of smelly molecules floating in the breeze.” Wilson's goal is to find out how those molecules alert animals to danger, food, and potential mates. As a postdoctoral fellow, she developed techniques to measure the electrical activity of individual neurons in the fruit fly brain in vivo. Now she runs a lab at Harvard Medical School, where she uses the technique to study how the brain processes information about odors and other types of sensory stimuli. By comparing the molecules and neural circuits that process sensory stimuli in different regions of the fly brain, Wilson hopes to reveal fundamental principles about how those circuits are organized and how they process information efficiently.

Ryohei YasudaRyohei Yasuda
Duke University Medical Center

Credit: ©2009 Bill Stagg

Ryohei Yasuda's undergraduate program in physics required hands-on research in a biophysics lab. There, he discovered a love for biology. Later, as a graduate student, he learned about the smallest rotary engine in biology. That engine is an enzyme called F1-ATPase, which produces ATP, the molecule cells rely on for energy. Yasuda attached a fluorescent filament to the enzyme so he could watch it spin. Now at Duke University, he has since developed more tools that allow him to watch proteins at work. He is imaging proteins inside tiny protrusions on the surface of dendrites, the branched arms of neurons that receive incoming signals. The biophysical techniques and fluorescent indicators Yasuda has developed allow him to see the protein machinery in these structures as they move and act to enable learning and memory.

Jennifer A. ZallenJennifer A. Zallen
Memorial Sloan-Kettering Cancer Center

Credit: ©2009 Rick DeWitt

Jennifer Zallen wants to understand how cells in a developing organism coordinate their movements to define the shape and structure of tissues and organs. She believes that the orchestration of this complex process can offer insights into fundamental development as well as the metastatic movement of cancer cells. The fruit fly embryos that she studies at the Memorial Sloan-Kettering Cancer Center take less than two hours to double in length and narrow in width to create the basic layout of their body plan. Zallen is interested in the genes that guide this elongation process. She is also combining quantitative live imaging with three-dimensional models to analyze large-scale cell movements and the mechanical forces that drive them.