A team of scientists, including M. Lisa Manning, assistant professor of physics in Syracuse University’s College of Arts and Sciences, has developed a model for studying tissue—specifically how it organizes into organs and layers during embryonic development.

Their findings are the subject of a Sept. 25th article in the journal Interface (Royal Society Publishing, 2013) and may have major implications for the study of tissue pattern formation and malformation. 

Central to their work was the question of whether embryonic tissue behaves more like a solid or a liquid—and why.

“We found that embryonic tissue was viscoelastic, meaning that it behaved like a liquid, if you pushed on it slowly, but like a solid, if you pushed on it quickly,” says Manning, who co-wrote the article with Eva-Maria Schoetz, assistant professor of biology and physics at the University of California, San Diego; and Marcos Lanio and Jared Talbot, both researchers in Princeton University’s Lewis-Sigler Institute for Integrative Genomics. “A mixture of cornstarch and water also behaves that way.”

Manning and her team found that viscoelasticity was the result of “glassy dynamics” in cells, caused by overcrowding. They discovered that cells within embryonic tissue were packed so tightly that they rarely moved—and when they did so, they expended considerable energy to squeeze past their neighbors.

She compares this behavior to riding on a subway. “If you're on a subway train that's not very crowded, it’s easy to move toward the exit and get off the train,” says Manning, an expert in theoretical soft condensed matter and biological physics. “But as more people get on the train, it takes longer to pick your way past them and exit. Sometimes, if the train is jam-packed, you miss your stop completely because you can't move at all."