Fruit flies provide new insight into body’s rhythms

Researchers from the University of Bristol have gained a new insight into how the circadian clock responds to changes in temperature. With collaborators from University College London, the University of Lausanne, and the University of Cambridge, the researchers discovered that a protein called Ionotropic Receptor 25a (IR25a), an evolutionary relative of Ionotropic Glutamate Receptors have a key role in entraining the brains of fruit flies to react to small changes in temperature. Their findings were recently published . Dr James Hodge , senior lecturer in the School of Physiology and Pharmacology , said: 'The circadian clock is basically a timer that allows an organism - be that a fruit fly or a human - to adjust their behaviour and physiology according to the time of day. The clocks are controlled both by changes in light and temperature.' 'However, the temperature sensitivity for adjusting the clock is remarkable, as the pace of the circadian clock is largely independent of the surrounding ambient temperature. In our experiments with fruit flies, we discovered that IR25a is part of a pathway to the circadian clock that detects small temperature differences. This pathway operates in the absence of known 'hot' and 'cold' sensors in the fruit fly's antenna, which points to the existence of periphery-to-brain temperature signalling channels.' The researchers investigated whether flies lacking IR25a were able to synchronize their circadian clocks to temperature changes.