Sequencing Analysis Examines Gene Regulatory Networks of Honeybee Soldier, Forager Brains

Gene regulatory networks differ between the brains of honeybees that become soldiers and ones that become foragers, especially when those bees belong to more aggressive colonies, a new study in Nature Ecology & Evolution reports. Unlike some other social insects, the roles of honeybees differ by age, rather than by size, with some older bees becoming soldiers that defend against territorial invasion and others foragers. But what determines the bees' roles is unclear. Building on a previous genome-wide association study that identified genes associated with colony aggression, researchers from the University of Illinois at Urbana-Champaign used bulk and single-cell sequencing to examine the expression of those aggression-linked genes in the brains of soldier and foraging bees. Their transcriptomic and gene regulatory analyses found structural network differences between soldiers and foragers, differences that were more pronounced when they were from aggressive colonies. "While a few studies have found potential heritable differences between soldiers and foragers, this study demonstrates that older honeybees may have the potential to take on either role," senior author Gene Robinson, director of the Carl R. Woese Institute for Genomic Biology at UIUC, says in a statement. "In colonies that are more aggressive, likely due to increased danger in the environment, older bees may just be more predisposed to become soldiers to help defend the colony."