Gene Mutation In Male Moth Allows It To Detect Female Even When Scent Is Altered
August 15, 2012


Brett Smith for - Your Universe Online

Because of a single gene mutation on the antenna of a male moth, he is able to receive a female moth´s Hail Mary pheromone pass from end zone-to-end zone even if she were to alter its scent.

According to a report published this week in the Proceedings of the National Academy of Sciences (PNAS), a team of researchers led by Montana State University entomologist Kevin Wanner identified the gene in male moths responsible for receiving and adapting to the ever-changing chemical signals emitted by female moths.

The results of the study could have a significant impact on the pest control industry, which spends more than $1 billion each year to control the pesky European corn borer alone. Wanner, who has dual assignments in the MSU Department of Plant Sciences and Plant Pathology, said scientists could eventually design custom pheromones that would control the pest population by keeping male moths from finding a mating partner.

Co-author and Wanner´s lab partner Jean Allen began work on the study by obtaining live corn borer moths raised in colonies at Cornell University by another co-author, Charles Linn Jr. Allen extracted RNA material from the male moths´ antennae and identified several candidates for a genetic mechanism that could receive pheromones.

Wanner then turned to Greg Leary and Michael Kavanaugh in the Center for Structural and Functional Neuroscience at the University of Montana for testing of the isolated receptors. The team also made a series of mutations that were to be later confirmed by Allen.

After analyzing several receptors and 47 possibilities for amino acid mutations, the researchers´ hard work finally paid off when they found an adaptation to a changing pheromone structure.

"It was a lot of work," Wanner added. "We had no rational way to know which one it was."

Wanner singled out the Opus Xpress as one instrument that was critical for their discovery. The device is typically used in pharmacology research to observe how different drugs react with their target receptor. When used in the context of this latest study, the instrument allowed the researchers to see how the pheromone receptors in the male moth interacted with various pheromone chemicals.

"Without this instrument, we would not have been able to identify the critical receptor and identify the specific mutation in that receptor that allowed it to adapt to a new pheromone structure," Wanner added.

Although scientists have been studying moth pheromones after isolating the chemical signals 50 years ago, they still know very little about the molecular device that makes communication so specific to a particular species, according to Wanner. Some moth species are so similar that scientists can only tell them apart using their pheromones.

To attract a mating partner, female moths release just nanograms of pheromone from a gland at the end of their abdomen. After being diluted into the air, the tiny amount of pheromones far too small for human´s olfactory receptors to detect, but male moths can detect it with the sensory cells on their antennae within 300 feet.