A single molecule released by the queen of a naked mole rat colony acts as a powerful contraceptive that stops all other females from breeding. Experiments by researchers in Berlin have identified the compound as isopropyl myristate and shown its effects in detail. The discovery explains how the queen maintains reproductive control without constant physical aggression.
Gary Lewin and colleagues at the Max Delbrück Center tested the molecule by spraying it daily into cages with male and female pairs. None of the females became pregnant while exposed to it, whereas almost all became pregnant when the spray was absent.
In colonies where the queen was removed, daily application of isopropyl myristate prevented fights and blocked breeding for three months. When the treatment stopped, high-ranking females began fighting within a week and one became pregnant after about three weeks.
The compound also altered levels of the hormones progesterone and prolactin. Lewin noted that the queen patrols her colony to deposit the scent, which persists for at least a day because it is only moderately volatile.
Other researchers, including Markus Zöttl at Linnaeus University and Chris Faulkes at Queen Mary University of London, described the evidence as compelling while noting remaining questions about detection mechanisms.
