“WE’RE CONVINCED THAT GENETIC CHANGES HAVE CLEAR EFFECTS ON BEHAVIOR, BUT WE DON’T HAVE ALL THE PIECES FILLED IN.” - ELIZABETH GLATER
Using the worm Caenorhabditis elegans, biology Professor Elizabeth Glater studies how genes evolve and the biological mechanisms by which the nervous system produces behavior.
“The answer to behavioral disorders lies in the neurons,” he
says. “The work isn’t always cool. But if you bear with it, you get cool results.” Conroy likes to remind himself that Gregor Mendel, the father of modern genetics, started out studying pea pods. Maria Morabe ’13, also a mathematical biology major, says
the project has enhanced her passion for biology. “It’s made me want to do more research in the future. The pure fun of learning about other organisms is what I like.” This learning involves watching, imaging and monitoring
how genetically mutated worms use their neural systems to sense food, choose which bacterial dinner they prefer, wriggle over to the meal, hang out and eat—the full dining experience. Summer research students Rachel Macfarlane ’15 and Melissa Chambers POM ’15 presented their fi ndings on the neural basis of food choice behavior at the Society for Neuroscience Undergraduate Poster Session in October 2012. “By understanding the neural circuitry of this relatively
simple choice, we can build up our understanding to situa- tions of more complexity,” Glater says. Using worms that are genetically mutated helps her clarify the links between genes and behavior. But there’s a lot yet to understand, she cautions. “We’re
convinced that genetic changes have clear effects on behavior, but we don’t have all the pieces fi lled in.”
In Drewell’s lab, understanding genetic behavior means thinking about honeybees and what he calls their reproductive
“tug-of-war.” The males, called drones, want offspring that are reproductively active, he explains. But the queen wants her daughters to be sterile so there are no new queens until the hive is ready to split. The Drewell lab hypothesizes that through a simple chemical modifi cation, called DNA methyla- tion, the ruling queen unconsciously switches off a few of the genes in her DNA and that of her offspring so that no new queens are born. It all seems a little Shakespearean, perhaps, but to Bush,
who is handling the billions of computations the molecular genetic research generated, it’s thoroughly modern, especially how methylation in honeybee reproduction might be linked to methylation observed in human cancer cells. “In a large number of human cancers, a causative compo-
nent of the cancer is a radical change in DNA methylation and the DNA of the cells,” Drewell says. “So anything we can do to understand DNA methylation can have an impact on hu- man health and the potential treatment of disease.” That understanding requires a laborious examination of
complex data. In a collaborative effort with the laboratory of Ben Oldroyd at the University of Sydney in Australia, genomic DNA from bee eggs and sperm was sent to China’s Beijing Genomics Institute for high-throughput sequencing, and a
SPRING 2013 Har vey Mudd College 25
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