The Smell of Success
A single scent that keeps a naked mole-rat colony in line
A new study from the Max Delbrück Center in Berlin shows for the first time that a single odorous chemical produced by naked mole-rat queens is enough to suppress reproduction in the rest of the colony, along with keeping rivalries from breaking out, even when the queen herself is nowhere nearby. The research team, led by Dr. Gary Lewin, identified the compound as isopropyl myristate, a substance already familiar from cosmetics as a common moisturizing solvent. The study was published in the journal Nature.
Naked mole-rats are unusual among mammals: they live in tightly organized underground colonies, much like bees or ants, with a single breeding queen at the top and large numbers of sterile workers below her. Roughly 450 of the animals live at the Max Delbrück Center in tunnel systems designed to mirror their natural burrows. Beyond their social structure, the rodents are known for unusually long lifespans, strong resistance to cancer, and a notable insensitivity to pain. These traits have made them a long-running subject of study at the institute.
A Scent That Rules Without a Presence
Earlier work by the Lewin lab had already shown that naked mole-rats use smell to tell colony members apart from outsiders. For the new study, the researchers set out to find whether scent might also explain how a queen holds onto exclusive reproductive control. Using mass spectrometry, they isolated a compound released only by queens: isopropyl myristate. Although it is odorless to humans, electrophysiological recordings and functional ultrasound imaging, which tracks blood flow as a marker of brain activity, showed that the animals' olfactory receptors detect it clearly, triggering signals in the brain's smell-processing centers.
Crucially, the compound did not need the queen herself to be present to have an effect. Simply dispersing isopropyl myristate into a colony each day was enough to prevent the fighting and mate-seeking that normally erupt once a queen dies or is removed. The same held true for individual pairs: a female and male from the same colony placed together will typically become sexually active within days, but exposure to queen-scented bedding, or even the pure compound alone, blocked that behavior.
Hormones Behind the Effect
The researchers traced the mechanism to hormone levels: isopropyl myristate raises prolactin, which suppresses fertility, while keeping progesterone, a hormone that promotes fertility, low. According to Lewin, that hormonal shift explains why colony members exposed to the queen's scent do not reproduce. The team also found that queens only produce the compound while pregnant. Once a queen can no longer breed, progesterone rises in other females, prolactin falls, and succession struggles begin again within the colony.
One Chemical, One Powerful Job
What struck the researchers most was the simplicity of the system. Where insect colonies typically rely on a whole mixture of pheromones to maintain social order, the naked mole-rat queen appears to manage it with a single molecule. First author Dr. Mohammed Khallaf described the finding as evidence that evolution can favor "tried-and-true" strategies even across very different species.
The international collaboration behind the study included groups in Berlin, Frankfurt, Jena, Munich, and Paris, along with researchers based in Egypt, South Africa, Tanzania, the Czech Republic, and the United States.
Source: Max Delbrück Center Press
Contact:
Prof. Dr. Gary Lewin
Max Delbrück Center for Molecular Medicine (MDC)
Molecular Physiology of Somatic Sensation Lab
Robert-Rössle-Straße 10 13125 Berlin