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Updated: Aug 26, 2026
Assessment of Sexual Behavior of Male Mice
Published on: March 5, 2020
Melanocortin-5 receptor deficiency reduces a pheromonal signal for aggression in male mice
Caurnel Morgan1, Ruth E Thomas, Weidong Ma
1Vollum Institute for Advanced Biomedical Research, Oregon Health and Science University, Portland, OR 97239, USA. cam2025@med.cornell.edu
Abstract:
Mice lacking the melanocortin-5 receptor (MC5R) exhibit decreased sensitivity to the stimulatory effects of systemic melanocortin injections on aggressive behavior. Because the pheromone-producing preputial gland expresses the MC5R, we tested the hypothesis that decreases in preputial pheromones underlie the behavioral deficit. Here we show that MC5R deficiency decreases preputial and urine levels of the sex pheromones, alpha- and beta-farnesene, relative to wild-type mice. We also demonstrate that farnesenes potently stimulate aggression in mice. Moreover, farnesene-stimulated aggression is reduced in MC5R-deficient mice, relative to wild-type mice. Our results suggest that activation of the MC5R promotes aggression by increasing farnesene signaling.
Insights
Mice lacking the melanocortin-5 receptor (MC5R) show reduced aggression due to lower levels of sex pheromones. Restoring pheromones may impact aggressive behavior, highlighting MC5R
Area of Science:
- Neuroendocrinology
- Animal Behavior
- Chemical Ecology
Background:
- The melanocortin-5 receptor (MC5R) is expressed in pheromone-producing glands.
- MC5R-deficient mice display altered aggressive behavior.
Purpose of the Study:
- To investigate if reduced pheromones mediate behavioral deficits in MC5R-deficient mice.
- To determine the role of MC5R in regulating pheromone levels and aggression.
Main Methods:
- Compared pheromone levels (alpha- and beta-farnesene) in MC5R-deficient and wild-type mice.
- Assessed the effect of farnesenes on aggressive behavior in both mouse groups.
- Measured farnesene-stimulated aggression in MC5R-deficient mice.
Main Results:
- MC5R deficiency significantly decreased preputial and urine levels of alpha- and beta-farnesene.
- Farnesenes were found to potently stimulate aggression in mice.
- Aggression induced by farnesenes was reduced in MC5R-deficient mice.
Conclusions:
- Decreased farnesene levels contribute to the behavioral deficits in MC5R-deficient mice.
- MC5R activation promotes aggression through enhanced farnesene signaling.
- This study links MC5R, pheromones, and aggressive behavior in mice.
