Project description:We performed a whole-genome transcriptomic analysis of pleometrotic queens infected by SINV-1, SINV-2 or co-infected with both viruses, to characterize patterns of gene expression associated with viral infection and identify genes responding differentially to the two viruses. We sampled fire ant queens in Gainesville, Florida, immediately after a mating flight. We arranged them in pairs based on having similar weights (range ±0.2 mg) to allow pleometrotic colony founding. We housed paired queens in nesting tubes in claustral conditions (no food or water) for one month. Thereafter, we collected queens in dry ice, we isolated total RNA from whole bodies and used it to quantify SINV-1 and SINV-2 viruses with real-time PCR. We selected 2 queens that were virus-free as controls, 3 SINV-1-infected, 4 SINV-2-infected and 11 co-infected by both viruses. These samples were processed for microarrays analysis.
Project description:Will be added/updated once the manuscript is finalized. Cardiocondyla obscurior queens. Three treatments: virgin queens, queens mated by real males, queens sham-mated (by sterile males). Queens collected 1 week and 8 week after mating. seven loops for queens collected 1 week after mating; nine loops for queens collected 8 weeks after mating. Five direct comparisons (with dye-swaps... so 10 arrays) were done of between 1 week and 8 week samples of queens mated by real males. Each sample is RNA from two queens (from different colonies). Samples were hybridized against Solenopsis invicta microarrays (signal was detectable for most clones!)
Project description:The evolution of eukaryotic organisms is often strongly influenced by microbial symbionts that confer novel traits to their hosts. Here we describe the intracellular Enterobacteriaceae symbiont of the invasive ant Cardiocondyla obscurior, 'Candidatus Westeberhardia cardiocondylae'. Upon metamorphosis, Westeberhardia is found in gut-associated bacteriomes that deteriorate following eclosion. Only queens maintain Westeberhardia in the ovarian nurse cells from where the symbionts are transmitted to late-stage oocytes during nurse cell depletion. Functional analyses of the streamlined genome of Westeberhardia (533?kb, 23.41% GC content) indicate that neither vitamins nor essential amino acids are provided for the host. However, the genome encodes for an almost complete shikimate pathway leading to 4-hydroxyphenylpyruvate, which could be converted into tyrosine by the host. Taken together with increasing titers of Westeberhardia during pupal stage, this suggests a contribution of Westeberhardia to cuticle formation. Despite a widespread occurrence of Westeberhardia across host populations, one ant lineage was found to be naturally symbiont-free, pointing to the loss of an otherwise prevalent endosymbiont. This study yields insights into a novel intracellular mutualist that could play a role in the invasive success of C. obscurior.
Project description:Fire ant queens were collected immediately after a nuptial mating flight and split into two groups: paired queens (pleometrosis) and individual queens(haplometrosis). All the queens were provided with a nesting chamber consisting of a glass tube half-filled with water, which was covered by a cotton ball and a layer of dental plaster. Tubes were sealed with a loose cap to provide air flow. Specimens were reared in the dark at 28C, 70% relative humidity under claustral conditions (no food and no water) for 1 month. After the eclosion of the first batch of workers (minims), incipient colonies were provided with water, sugar water and frozen crickets. Glass tubes were set open in pencil boxes coated with Fluon to prevent escape. Queens were subsequently monitored daily until it was possible to identify the social rank of the two cofoundresses in pleometrotic couples.