Wednesday, December 8, 2010

Canadian researchers develop technique to track embryo development

From The Record:

WATERLOO, Canada — Seeing the microscopic forces guiding cell and tissue development in the embryo is now possible with a new technique developed by University of Waterloo researchers.

Understanding these forces is important because even slight changes can lead to birth defects, including spina bifida, cleft lip and palate and heart defects.

“These are all caused because the tissues didn’t move in exactly the right way,” said Wayne Brodland, a professor of civil and environmental engineering and leader of the international team.

Their research on the technique called video force microscopy was published earlier this week in the Proceedings of the National Academy of Sciences.

Forces are at work in cells and tissues as an embryo develops, moving them in precise ways to form organs and other structures. But sometimes that goes wrong and defects appear.

“The tissues have to move into just the right locations,” Brodland said.

Until now, researchers could see the effect of that tug-of-war between different tissues, but couldn’t determine the strength of those forces. This new technique gives a very detailed picture of what’s going on.

“We can say in a precise way what exactly the forces are,” Brodland said.

UW researchers started with time-lapse photos of Drosophila embryos, a small fly often used by scientists studying embryogenesis, how embryos form, from the Princeton University lab of Nobel Prize-winning scientist Eric Wieschaus.

Those images were digitized and analyzed by a computer program designed to measure the changing forces and how those vary in normal and abnormal embryos. Just a 20 per cent difference in those forces, Brodland discovered, can cause defects to appear in an embryo.

“That’s a pretty small change,” he said.

Figuring out why that goes wrong is the first step in learning how to prevent defects, Brodland said. Experts can then look at the various factors that affect those forces in an embryo, including genetics, nutrition and environment.

Brodland’s team is now fine-tuning the technique, which he expects will become a common research tool to investigate all sorts of events in embryo development.