Rhythm Of Life - Genetics Tells Us Why Italian And English Flies Act Differently

Italian flies behave completely differently from English ones – and the difference lies in their genes, a new study from the University of Leicester has discovered.

The finding in the world renowned Department of Genetics at the University of Leicester has shed new light on the rhythm of life.

The Leicester team has published its findings in two back-to-back papers in the journal Science and further develops a decade-old Leicester discovery.

The Leicester research relates to two important aspects of life:

- The 24-hour body clock known as the circadian cycle

- The seasonal cycle (hibernation) known as diapause in insects

Professor Bambos Kyriacou and his team in Genetics found for the first time a connection between these two cycles in a single gene. Their finding settles a decades-old argument about the correlations between the two cycles.

This gene, called timeless, was found to control the 24-hour rhythm of the fruifly as well as its seasonal cycle.

Professor Kyriacou said: “The story begins in 1997 with a discovery by Dr Ezio Rosato, now Reader in the Genetics department, but then a postdoc in my lab. He found that the timeless gene came in two different versions L-tim and S-tim. In collaboration with Professor Rudi Costa’s group in Padova Italy, a study of natural European fly populations revealed that the L-tim variant was found predominantly in the south of Europe, and S-tim in the north.

“Dr Eran Tauber, now Lecturer in Genetics, but also formerly a postdoc in my laboratory, then showed that L-tim had been derived from S-tim by a mutation that occurred about 8000 years ago in southeastern Italy, and then had spread by natural selection in all directions.”

Professor Kyriacou explained that this occurred as a result of the different environments, particularly daylight conditions and temperature, between northern and southern Europe.

“These studies are important, not just because they show that the timeless gene connects the two major biological cycles on our planet, but as a pretty complete evolutionary story,” he said.

Source: University of Leicester