COLUMBIA, Mo. -- For years, doctors have used a procedure called chromosome painting to help identify aberrations in chromosome pairs. When used in tests on a developing fetus, the process can help identify such complications as Down syndrome. Now, a team of University of Missouri-Columbia researchers have developed a related procedure for plants.

James Birchler, MU professor of biological sciences, whose lab tested the process on several varieties of corn, says the new research will be useful for many studies of chromosomes in corn. It could ultimately help scientists produce more disease resistant corn and other plants. The work by Birchler, MU post doctoral fellow Akio Kato and graduate student Jonathan C. Lamb is published online this week in the Proceedings of the National Academy of Sciences, and one of the lab's slides showing the precisely color-coded chromosomes will adorn the printed journal's cover.

Until now, it has been impossible to identify all corn chromosomes from root tips under a microscope. Using the researchers' technique, repetitive chromosome sequences in cells are isolated and labeled with a chemical that glows under fluorescent light. These fluorescent probes only stick to the chromosome that exactly matches it and each of the ten pairs of chromosomes is able to be distinguished. If there is an irregularity of any kind in any of the chromosomes, it is readily apparent as the cell is viewed.

Birchler says the blue, red, green and white colors create an identification process that is a big leap in cutting out time-intensive steps in research.

"It was possible before to pick out the chromosomes in meiosis, the time when chromosomes are pairing together in a plant's flower," Birchler said. "The new procedure will allow the chromosomes to be distinguished in other tissues, which will be very useful for identifying and following how chromosomes behave."

Birchler's research is funded by the National Science Foundation, the USDA and Monsanto Company.