When comparing the mutant males with wild-type males, study results showed that all wild-type males mated with test females, while none of the mutants engaged in sexual behavior with the females. "Typically, when you take a female and put her in a cage, the male will initially sniff her, a process known as chemoinvestigation, and then mate with her," Shah says. "But the mutants without the MOE even showed a profound defect in initiating chemoinvestigation of the test females."
When a wild-type male encounters another male, he will typically sniff the male and then initiate a fight. However, the mutant males were defective in sniffing the test wild-type males, and they did not attack the wild-type males, Shah notes. "This suggests a broad and essential role for the MOE in regulating mating and aggression."
More research is needed to understand the role of the olfactory system and human behavior, but clearly this is an important connection for people, according to Shah. "The booming perfume industry attests to our belief that odors can attract potential suitors, and there are some studies in humans that suggest pheromone-type signals might have subtle effects on the regulation of certain physiological functions, such as the menstrual cycle."
Stimulation of the other senses also has a direct effect on behavior, he adds. "When you touch a hot pan, you immediately draw your hand away. Or, if you place your finger in an infant's palm, the baby will grasp it instinctively."
The current research findings might also be relevant for controlling pest populations, which utilize olfactory cues in a manner similar to mice, according to Shah.