Scientists have identified more than 1,500 genetic differences between migratory and non-migratory flies.
The University of Exeter-led team captured migrating insects as they flew over a mountain pass and sequenced the active genes to determine what determines migratory behaviour.
This genetic information was then compared to that of non-migrating summer flies.
“We identified 1,543 genes whose activity levels differed among migrants,” said lead author Toby Doyle, from the Center for Ecology and Conservation at Exeter’s Penryn Campus in Cornwall.
“What really struck us was the remarkable range of roles that these genes play.
“Migration is very demanding from an energetic point of view, so finding genes for metabolism was not a surprise, but we also identified genes involved in muscle structure and function, hormonal regulation of physiology, immunity, stress resistance, flight and feeding behavior, sensory perception and for increasing longevity. “
Every autumn, billions of migratory flies leave northern Europe and make the long journey south.
Their journey goes through the Pyrenees, where they concentrate through high mountain passes.
“It’s an amazing sight to see, an endless flow of hundreds of thousands of people over a 30-meter pass,” said Dr. Carl Wotton.
When the researchers began to sequence these genes by function, they found that sets of genes were activated in concert: insulin signals for longevity, pathways for immunity, and genes that lead to the production of octopamine, the equivalent of adrenaline, the fight-or-flight hormone in insects, over long periods of time. – flight range.
“These pathways have been integrated into migratory hoverflies and modified by evolution to allow long-distance movement,” Dr Wotton said.
The work provides a powerful genomic resource and theoretical framework to guide future research on the evolution of migration.
Dr Wotton added: “This is an exciting time to be studying the genetics of migration.
“Our research has already identified several genes previously associated with butterfly migration, suggesting the existence of a common ‘migratory gene package’ that controls migration between multiple animals.”