Animals Use Pheromones to Communicate, but Do Humans?

Aug. 28, 2000 -- Some couples just seem to have a certain chemistry together. Research is showing that they might be exactly right.

Scientists now believe they have found the first human gene associated with the function of pheromones, odorless molecules wafting through the air that signal key survival responses in animals, like dealing with danger or finding a mate.

While rodents and other creatures essentially are reactive animals that depend heavily on pheromones for behavioral cues, it has been a topic of debate whether humans kept any pheromone function along the course of evolution. Humans use their larger brains to rely more on judgment and complex sensory cues, such as vision.

Researchers studying animals have shown how pheromones work, tracing complex neurological paths to stimulate parts of the brain that are deeply rooted in instinct.

Scientists have had their suspicions that humans also use pheromones to communicate with each other chemically. But only recently have experts been able to tease out the parts of the human body that might function this way.

Neurogeneticists at Rockefeller University and Yale say they have isolated a human gene, labeled V1RL1, they believe makes a pheromone receptor, or the chemical's personal reserved parking place. Pheromones would attach to this receptor when they are inhaled into the mucous lining in the nose.

"This is the first convincing identification of a human pheromone receptor," said University of Colorado biochemist Joseph Falke, PhD.

Rodents and other mammals also have the V1RL1 gene, and they rely heavily on pheromone cues to survive. However, it has not been determined whether the gene is active in humans or what sort of activity the gene could trigger.

"The ultimate test will be to find a pheromone that binds to the receptor and triggers a measurable physiological response," Falke said.

The research was published in the September issue of the journal Nature Genetics.

Researchers took samples from a gene bank and scanned them for matches to the rodent genes from the V1r family. They found eight matches in human genetic material.

Further testing showed that seven of the eight human V1r genes are inoperative. The potentially functional gene, V1RL1, subsequently was found in 11 out of 11 randomly chosen people from varying ethnic backgrounds, researchers said.

"In mice, we think there are more than 100 functioning genes in the V1r family," said Ivan Rodriguez, PhD, of Rockefeller University, lead author of the study. "But in humans, V1RL1 may very well be the sole functioning gene in the family."

"Why has it hung around all this time?" said Charles Wysocki, MS, PhD, of the Monell Chemical Senses Center in Philadelphia. "It must be very important if it has outlived all of its predecessors."

Scientists aren't sure what happened to the other 99 genes. 

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Pheromone System of 2011