Honeybees are increasingly under threat, even recently making it onto the endangered species list in the US for the first time. In a development that could help save these vital creatures from extinction, researchers from York University have identified a group of genes that appear to be related to how hygienic a particular colony of bees is, and selective breeding for these genes could help fight colony collapse.

In the last few years, populations of bees have drastically fallen across much of the world. No single cause has been agreed upon yet, but plenty of possible explanations have been proposed, including infections of parasites or our overzealous use of pesticides. Whatever the reason, the serious problem is that bees are one of the bottom blocks in the Jenga tower of natural ecosystems. Once they're gone, plants that rely on bees for pollination will follow, and so will the animals that eat those plants, and so on.

For the new study, the York researchers investigated a positive trait that certain colonies seem to have. Some beehives seem to be generally "cleaner" than others, and worker bees in these colonies have been observed removing the sick and the dead from the hive. These hygienic behaviors have been linked with higher chances of survival for the colony as a whole, since the pathogens are likely being taken out too.

Ideally, breeding colonies to be cleaner could make for hardier bees, offsetting some of the rapid decline of several species. So the York team sequenced the genomes of three populations of honeybees – two of which had been bred to be highly hygienic, while the third colony had more normal levels of cleanliness.

The difference is clear between "unhygienic" bee colonies (left) and hygienic ones (right) York University

When they compared the three genomes, the team was able to identify at least 73 genes that seemed to be related to hygiene behaviors. With those candidates found, the researchers plan to develop tools that help beekeepers breed cleaner bees, which ultimately may help reduce the number of colonies that go on to collapse.

"Social immunity is a really important trait that beekeepers try to select in order to breed healthier colonies," says Professor Amro Zayed, corresponding author of the study. "Instead of spending a lot of time in the field measuring the hygienic behavior of colonies, we can now try breeding bees with these genetic mutations that predict hygienic behavior."

The research was published in the journal Genome Biology and Evolution.

Source: York University