32 research outputs found
Data from: Colony-level behavioral variation correlates with differences in expression of the foraging gene in red imported fire ants
Among social insects, colony-level variation is likely to be widespread and have significant ecological consequences. Very few studies, however, have documented how genetic factors relate to behavior at the colony level. Differences in expression of the foraging gene have been associated with differences in foraging and activity of a wide variety of organisms. We quantified expression of the red imported fire ant foraging gene (sifor) in workers from 21 colonies collected across the natural range of Texas fire ant populations, but maintained under standardized, environmentally controlled conditions. Colonies varied significantly in their behavior. The most active colonies had up to 10 times more active foragers than the least active colony and more than 16 times as many workers outside the nest. Expression differences among colonies correlated with this colony-level behavioral variation. Colonies with higher sifor expression in foragers had, on average, significantly higher foraging activity, exploratory activity, and recruitment to nectar than colonies with lower expression. Expression of sifor was also strongly correlated with worker task (foraging versus working in the interior of the nest). These results provide insight into the genetic and physiological processes underlying collective differences in social behavior. Quantifying variation in expression of the foraging gene may provide an important tool for understanding and predicting the ecological consequences of colony-level behavioral variation
Recommended from our members
What Goes Up Might Come Down: the Spectacular Spread of an Endosymbiont Is Followed by Its Decline a Decade Later
Facultative, intracellular bacterial symbionts of arthropods may dramatically affect host biology and reproduction. The length of these symbiont-host associations may be thousands to millions of years, and while symbiont loss is predicted, there have been very few observations of a decline of symbiont infection rates. In a population of the sweet potato whitefly species (Bemisia tabaci MEAM1) in Arizona, USA, we documented the frequency decline of a strain of Rickettsia in the Rickettsia bellii clade from near-fixation in 2011 to 36% of whiteflies infected in 2017. In previous studies, Rickettsia had been shown to increase from 1 to 97% from 2000 to 2006 and remained at high frequency for at least five years. At that time, Rickettsia infection was associated with both fitness benefits and female bias. In the current study, we established matrilines of whiteflies from the field (2016, Rickettsia infection frequency = 58%) and studied (a) Rickettsia vertical transmission, (b) fitness and sex ratios associated with Rickettsia infection, (c) symbiont titer, and (d) bacterial communities within whiteflies. The vertical transmission rate was high, approximately 98%. Rickettsia infection in the matrilines was not associated with fitness benefits or sex ratio bias and appeared to be slightly costly, as more Rickettsia-infected individuals produced non-hatching eggs. Overall, the titer of Rickettsia in the matrilines was lower in 2016 than in the whiteflies collected in 2011, but the titer distribution appeared bimodal, with high- and low-titer lines, and constancy of the average titer within lines over three generations. We found neither association between Rickettsia titer and fitness benefits or sex ratio bias nor evidence that Rickettsia was replaced by another secondary symbiont. The change in the interaction between symbiont and host in 2016 whiteflies may explain the drop in symbiont frequency we observed.12 month embargo; published online: 12 August 2019This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]