To get a sense of how the wasp brain evolved over time, she and taxonomist Susanne Schulmeister of the American Museum of Natural History in New York City compared the mushroom bodies of parasitic wasps with those of nonparasitic wasps, which represent the very oldest form of wasp.
Here we found no significant overlap with the wasp brain differentially expressed list; however, when we compared this expanded honey bee aggression list to the wasp "brain caste-associated" genes, we again found significant overlap (Table 3).
There was no significant overlap when we compared to the 63 wasp "brain dominance-associated genes" (data not shown).
We hypothesized that paper wasp brain gene expression patterns would be related to gene expression associated with caste, exposure to queen pheromone and/or aggression in honey bee workers.
To further investigate the potential connection between genes related to dominance (our study) and aggression, we compared our complete wasp brain differentially expressed gene list to microarray studies identifying brain-expressed genes associated with aggression in Drosophila melanogaster fruit flies [ 44] and maternal aggression in mice [ 45].
We did find a significant overlap between wasp brain differentially expressed gene lists and those associated with differences in worker foraging behavior in honey bees in one study [ 42], but this result was not confirmed in comparisons with a second study on the same behavior [ 43].
Lists of genes with significant overlaps are highlighted in bold and a complete list of overlapping transcripts are provided in Additional file 2. We found no significant overlap between wasp brain differentially expressed transcripts and those differentially expressed in honey bees in association with caste differences [ 41] or response to queen pheromone [ 9].
Using a dye that labels neurons, Gal identified stringlike axons stretching between the structures on the stinger and the wasp's brain, further evidence that these axons provide the wasp with information about what it is about to sting.
We extracted each individual wasp's brain and ovary RNA using a PicoPure (Evrogen, Moscow, Russia) kit.
Whereas the immobilized SH3 domain of Abp1 quantitatively affinity purified endogenous N-WASP from brain extracts, both Abp1 ΔSH3 and a mutated version of the SH3 domain (P422L and G425R; [18]) showed no affinity for N-WASP (Figure 4C).
