Research out of Brown University has found that cells move in ways that are much more complex than previously thought. It’s yet another example of the complexity of life’s design that consistently surprises biologists.
“We’ve learned that cells move in much more complex ways than previously believed,” said Christian Franck, assistant professor in engineering at Brown and the co-lead author of the study published online in the Proceedings of the National Academy of Sciences. “Now, we can start to really put numbers on how much cells push and pull on their environment and how much cells stick to tissues as they move around and interact.”
In the study, Franck and co-lead author Stacey Maskarinec, who both conducted the experiments while graduate students at the California Institute of Technology, placed cells on top of a 50-micron-thick water-based gel designed to mimic human tissue. They added into the gel spheres about a half-micron in diameter that lit up when jostled by the cells’ actions. By combining two techniques — laser scanning confocal microscopy and digital volume correlation — the scientists tracked the cells’ movement by quantifying exactly how the environment changed each time the cell moved. The team recorded results every 35 minutes over a 24-hour period.
What they found was cells move in intriguing ways. In one experiment, a cell is clearly shown operating in three dimensions by extending feelers into the gel, probing at depth, as if thrusting a leg downward in a pool. The Brown and Caltech scientists also found that as a cell moves, it engages in a host of push-pull actions: It redistributes its weight, it coils and elongates its body, and it varies the force with which it “grips,” or adheres, to a surface. Combined, the actions help the cell generate momentum and create a “rolling motion,” as Franck described it, that is more like walking than shuffling, as many scientists had previously characterized the movement.
“The motion itself is in three dimensions,” Franck said.
Brown University (2009, December 17). Cells move in mysterious ways, experiments reveal. ScienceDaily. Retrieved December 17, 2009.