Researchers Find Clues to Pesticide Resistance

WEST LAFAYETTE, Indiana,, May 6, 2004 (ENS) - A Purdue University research team has found a set of genes that may orchestrate insects' ability to fight the effects of pesticides.

The study of fruit flies "suggests that more than one gene may be involved in making insects resistant to certain pesticides," said Barry Pittendrigh, associate professor of entomology.

"Using a music analogy, metabolic resistance may not be a single individual playing a single instrument," he added. "It is more likely a symphony with numerous instruments playing a role in producing the music."

Pittendrigh said the ultimate aim of the research is to develop methods to prevent insect damage to plants.

Results of the initial study are published in the May 4 issue of "Proceedings of the National Academy of Sciences."

The researchers looked at some 14,000 genes from both metabolically resistant and non-resistant wild-type fruit flies.

They identified dozens of genes that were different in resistant fly lines compared to non-resistant wild-type flies.

Joao Pedra, an entomology doctoral student and lead author of the paper, said data from the study suggest that more than one detoxification gene is over-expressed in resistant insects.

"Different resistant fly lines also may have different levels of expression of these genes," Pedra said. "This may affect how resistant they are to a pesticide."

Knowing genes involved in resistance and their relationship to each other would provide scientists with information needed to develop ways to halt insects' detoxification of chemicals designed to kill them.

"It would be great if we would ultimately identify a 'conductor' gene that is critical for directing the biochemical processes that allow insects to detoxify pesticides," Pittendrigh said. "A gene or genes that may be critical for resistance, in turn, may become targets, enabling us to develop compounds to control pesticide resistant insects."