Abstract

not-yet-known not-yet-known not-yet-known unknown The expression of circadian clock genes shifts with changes in behavior. We examined the association of clock genes and those associated with behavioral plasticity in the diurnal, desert harvester ant, Pogonomyrmex barbatus and in a distantly related, tropical nocturnal species, Camponotus floridanus. A comparison of daily transcriptome in light-dark (LD) and total dark (DD) of ants in a laboratory colony of P. barbatus showed that most genes were expressed in both LD and DD at about the same level, while 460 genes were expressed only in LD, including many associated with olfaction and juvenile hormone signaling. Network analysis identified eleven modules of co-expressed genes under LD conditions; one module (C2) contained most of the clock-controlled genes that show circadian expression in both LD and DD, including Period and Clock. The clock-controlled genes in module C2, and in another neighboring module (C1) with circadian rhythms in DD only, showed significant overlap with those found in previous work to be associated in P. barbatus with plasticity in the regulation of foraging activity to manage water loss. The set of genes expressed in the ant brains with 24h rhythms were similar in P. barbatus and C. floridanus. The P. barbatus modules C2 and C1 showed a strong overlap with C. floridanus genes previously shown to differ in their periodicity of daily rhythms in nurses and foragers. The results suggest that genes associated with both circadian clock and behavioral plasticity may be broadly conserved in ants.