Gene expression profiles associated with communication skills in golden ants
Eyal Privman, Daphna Gottlieb
Department of Evolutionary and Environmental Biology, Institute of Evolution, University of Haifa, Israel; Department of Evolutionary and Environmental Biology, Institute of Evolution, University of Haifa, Israel; and Department of Food Quality & Safety Institute for Postharvest and Food Sciences Agricultural Research Organization, Volcani Center, Israel
Many empirical and theoretical studies investigated the frequency at which group members make use of information transfer among them, that is, social information use. Although social information use is considered highly beneficial, in some highly social species some individuals engage exclusively in individual information acquisition. While there has been much empirical research on factors affecting the frequency of social information use, the evolutionary perspective has mainly been theoretically addressed. Here, we conducted behavioral experiments coupled with functional genomic analyses to identify genes underlying the observed variation in social information use in the ant Camponotus sericeus (Forel). C. sericeus workers recruit via tandem running. We predicted that the difference between ants participating in tandem runs and ants foraging alone is associated with differences in their gene expression. We used a tracking system to monitor individually-tagged workers of five colonies as they foraged in a 1.5 m long arena, and analyzed tandem running events. Forty individuals were selected based on their behavioral characteristics to represent three behavioral types: tandem leaders, tandem followers, and solitary foragers. RNA-seq libraries were constructed from total head mRNA extracts and sequenced to produce a total of 1083 million reads, an average of 27 million reads per sample. The reads were mapped to a de novo transcriptome assembly to quantify gene expression. Gene expression analysis identified genes differentially expressed between the behavioral types, as well as association between gene expression levels and behavioral characteristics of the tandem run, which are indicative of the strength of communication between the leader and follower. These results will provide first candidate genes for elucidation of the genetic and evolutionary basis of the sophisticated communication observed in ant societies.