Increased activity during the summer caused by genes

The warm temperature on a summer’s day is often a time for relaxing, but researchers from the Department of Genetics have suggested that a ‘thermosensory’ gene could be responsible for changes in behaviour in different climates.  

The study explores how the biological clock can be affected by the environment by examining the fruitfly Drosophila melanogaster, which shows 24 hour biological cycles and is used as a model organism for studies into human rhythms.

Like many humans, the fly has a ‘siesta’ on a hot afternoon, but only under artificial laboratory conditions - flies do the opposite when in the wild and show a large afternoon locomotor response under naturally cycling summer temperatures. The hyperactivity of the fly in the wild is controlled by a gene called ‘TrpA1’, which acts as a thermosensor and causes an environmentally-induced change in behaviour.

Professor Bambos Kyriacou from the research team said: “Based on our findings, we have found that investigating animals in their natural environments rather than in labs helps us to better understand how genes control behaviour and can help us to avoid making erroneous conclusions based only on artificial laboratory situations – of course this means that some of our well-established, decades-old interpretations about how the biological clock works could be in need of significant revision.”

The paper entitled ‘Drosophila circadian rhythms in seminatural environments: Summer afternoon component is not an artifact and requires TrpA1 channels’ is published in the journal Proceedings of the National Academy of Sciences (PNAS).