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FALL 2006
Two for the Show
by Stephanie Schupska and Helen Clemens

The word “recent” takes on a whole new meaning when you’re talking to Andrew Paterson, a plant biologist at the University of Georgia. His study of polyploids — organisms that possess two sets of chromosomes from each parent instead of one — compels him to look hundreds of millions of years into evolutionary history.

Rice, which underwent duplication of its entire genome some 60 million years ago, is an example of an “ancient polyploid,” Paterson said. By comparison, polyploid plants such as cotton, wheat, sugar cane, alfalfa, potatoes and tobacco mutated from 10,000 to millions years ago — “recently,” in Paterson’s view.

His research suggests that polyploidy may be far more common than the scientific community previously believed. Paterson’s lab has demonstrated that several organisms thought to have acquired just one set of chromosomes from each parent are actually polyploids.

“All plants and even some animals — fish in particular — may be the results of ancient polyploidization,” Paterson said. “There are genes whose functions appear to be so necessary that it’s actually advantageous to have a spare copy.

“What we want to know now,” Paterson noted, “is what happens to the genes after they are duplicated.” Thus his botanical studies often investigate which genes a plant “chooses” to dispose of during evolution and which ones it passes along.

Polyploids can also be synthetically created, which may help researchers develop hardier crops; the additional genes might supplement disease-resistance, for example.

“The things that we’re learning by looking at ancient polyploids and sorting out the common features of the ones that survived may lead to strategies that help us make better use of synthetic polyploids and improve crops,” Paterson said.

For more information, email Andrew Paterson at paterson@uga.edu.