Signatures of evolution in the honeybee genome

Genetic changes that helped honeybees adapt to their local environment over 300,000 years ago are reported in a study published online this week in Nature Genetics. The findings provide an important resource to study the impact of climate change and disease on honeybees.

The honeybee, Apis mellifera, is an important pollinator species that has recently suffered significant colony loss. Though the cause of this is unknown, it has been suggested that it may be related to climate change or the spread of species specific disease. Studying the genetic variations between honeybee populations may help scientists understand how bees have adapted to different environments and why some bee populations are able to resist disease.

Matthew Webster and colleagues sequenced the genomes of 140 honeybees from 14 populations representing Europe, Africa, the Middle East, the US and Brazil. They found nearly 3,000 genes that showed evidence of adaptive evolution. These genes were involved in many important functions, such overwintering and immunity. The authors also found that changes in the climate over the last 300,000 years affected the size of honeybee populations. For instance, African populations peaked during glacial periods while European populations peaked during interglacial periods.