Quit bugging me: Phorid fly parasitoids affect expression of an immune gene in foraging fire ant workers

This data contains RT-qPCR and diet measurements for quantifying gene expression of red imported fire ant, Solenopsis invicta workers in the presence and absence of the parasitoid fire ant decapitating fly, Pseudacteon curvatus, and assessing the amount of food after exposure to P. curvatus, respectively. The genes investigated were the Solenopsis invicta foraging gene (Sifor), odorant binding protein 11 (OBP-11), abaecin, defensin-2 (Def-2), cytochrome P450 4C1-like (CYP4C1-like), and hymenoptaecin (hym). Ribosomal Protein 18 (RPL18) was used as the reference gene. These genes of S. invicta workers of unknown infection status in fire ant colonies exposed to decapitating flies and control colonies were observed over a 48-h period. Two diets were measured before and after in control and treatment colonies (i.e., colonies exposed to P. curvatus).

Methods
Fire ant (S. invicta) colonies were collected and split into two sub-colonies. Containers were designed and created to serve as behavioral assay arenas. Behavioral assays were conducted in a climate-controlled laboratory, started between 13:30 and 14:20 pm, and performed over 48 hours. Each treatment colony was exposed to 10 decapitating flies (P. curvatus). Each experiment lasted 48 hours.

Food was measured in grams (g) using a scale. Data was hand-collected and then transferred to Excel where basic statistics were performed (t-tests). Fire ant workers were collected during each experiment at hours: 0, 6, 24, 30, and 48 h. They were snap-frozen on dry ice and stored at -80°C prior to RNA extraction. We assayed relative expression of Sifor, OBP11, Hym, CYP4C1-like, abaecin, and Def-2, mRNA from pooled whole body fire ant workers/foragers relative to RPL18 (an endogenous control gene) using real-time qPCR techniques on a QuantStudioTM Pro System with PowerUpTM SYBRTM Green Master Mix and manufacturer’s protocols.

Statistical analyses were conducted using paired t-tests of the DCt scores to compare differences in gene expression levels in fire ant workers at each sampling time point in the control (i.e., decapitating flies absent) and treatment (i.e., decapitating flies present) colonies.