title: Molecular and social regulation of worker division of labour in fire ants.
abstract: Reproductive and worker division of labour (DOL) is a hallmark of social insect societies. Despite a long-standing interest in worker DOL, the molecular mechanisms regulating this process have only been investigated in detail in honey bees, and little is known about the regulatory mechanisms operating in other social insects. In the fire ant Solenopsis invicta, one of the most studied ant species, workers are permanently sterile and the tasks performed are modulated by the worker's internal state (age and size) and the outside environment (social environment), which potentially includes the effect of the queen presence through chemical communication via pheromones. However, the molecular mechanisms underpinning these processes are unknown. Using a whole-genome microarray platform, we characterized the molecular basis for worker DOL and we explored how a drastic change in the social environment (i.e. the sudden loss of the queen) affects global gene expression patterns of worker ants. We identified numerous genes differentially expressed between foraging and nonforaging workers in queenright colonies. With a few exceptions, these genes appear to be distinct from those involved in DOL in bees and wasps. Interestingly, after the queen was removed, foraging workers were no longer distinct from nonforaging workers at the transcriptomic level. Furthermore, few expression differences were detected between queenright and queenless workers when we did not consider the task performed. Thus, the social condition of the colony (queenless vs. queenright) appears to impact the molecular pathways underlying worker task performance, providing strong evidence for social regulation of DOL in S. invicta.
authors: Department of Entomology, Center for Pollinator Research, The Pennsylvania State University, University Park, PA, 16802, USA; School of Biological Sciences, Royal Holloway University of London, Egham, TW 20 0EX, UK.
authors: Fabio
authors: F
authors: Manfredini
authors: Christophe
authors: C
authors: Lucas
authors: Michael
authors: M
authors: Nicolas
authors: Laurent
authors: L
authors: Keller
authors: Dewayne
authors: D
authors: Shoemaker
authors: Christina M
authors: CM
authors: Grozinger
mesh_terms: D000818:Animals; D001000:Ants / Q000235:genetics* / Q000502:physiology*; D001070:Appetitive Behavior; D001522:Behavior, Animal; D005260:Female; D015870:Gene Expression; D017344:Genes, Insect; D020411:Oligonucleotide Array Sequence Analysis; D012919:Social Behavior; D059467:Transcriptome
keywords: division of labour; fire ants; foraging workers; microarrays; queen pheromone; sociogenomics