By combining two genome-wide screens, the researchers were able to narrow down the dozens of genes identified by the first screen to just 17 that made both cut-offs -- a number small enough to be cost- and time-efficient to consider in some detail. Their report appears in the April issue of Molecular Biology of the Cell.

"Data created from new genome-scanning techniques can be overwhelming. Reading all there is to know about 50 genes to figure out what new knowledge may be lurking in the haystack is very difficult," says Forrest Spencer, Ph.D., associate professor in Hopkins' McKusick-Nathans Institute of Genetic Medicine. "But by overlapping information from two screens, we were able to figure out what Mother Nature was trying to tell us that wasn't too complicated for us to understand."

While the researchers had hoped their screens would reveal new genes and their functions, they instead identified genes previously linked to two other aspects of shepherding genetic material during cell division. Fifteen of the highlighted genes were already known to help ensure the accuracy of copied DNA and two help move chromosomes to opposite ends of the dividing cell.

But the researchers' results give these "old" genes new jobs, associating them with cohesion, the little-understood process of keeping a chromosome and its copy together until the cell is ready to split in two. If the "sister" chromosomes aren't kept together, both copies could end up on one side of the dividing cell. Another problem is that the copies could undergo extra rearrangements, risking loss of important genes.

"If there's no cohesion, the cell will die," says Spencer. "However, if the process sometimes works and sometimes doesn't, some c
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Contact: Joanna Downer
jdowner1@jhmi.edu
410-614-5105
Johns Hopkins Medical Institutions
22-Apr-2004