Actinomycetes seem to combat primarily Escovopsis spp., but inhibitory effects of lower intensity have been demonstrated against other fungi, including entomopathogenic fungi ( Haeder et al., 2009). Under more vulnerable conditions, where the immune system of younger workers is less active, actinobacteria may offer protection against pathogens. I-BET-762 clinical trial It has been demonstrated that other insects can be protected by symbiotic actinobacteria against pathogens, parasitoids or predators. The actinomycetes’ ability to produce a wide range of secondary metabolites, including several with antibiotic

properties, partially accounts for this trend in insect-actinomycetes symbioses ( Kaltenpoth, 2009). From Hydra to humans, we can find examples of epithelia selecting the bacterial community to live on them ( Fraune and Bosch, 2010). In Attini ants, actinomycetes live in specialized structures that are elaborate cuticular crypts with associated exocrine glands ( Currie et al., 2006). Their abundance is age-dependent, and their dependence on metapleural gland secretion supports the hypothesis of active mechanisms regulating their presence ( Poulsen et al., 2003b). Thus, another hypothesis to be tested consists of verifying an increase of ectosymbionts when the workers are immunocompromised. In our study, external workers

exhibited a more elevated respiratory rate than did workers with actinobacteria. Although it is not possible to separate the fraction of energy due to the presence actinomycetes, it is at least evident that actinomycetes do not pose selleck chemical a high energy cost to workers. Our data support a pattern of increase of metabolic rate as Acromyrmex Clomifene workers age and their immune system achieves maturation, and at this point, they are able to perform external activities. Actinobacteria do not change the cuticular profile or the hydrocarbon quantities of the host ant; this is in contrast

to the fungus symbiont, which is important in colonial recognition (Viana and Lenoir, 1996). This indicates that nestmate recognition is not modified, which was expected because foragers and some internal ants do not have the actinobacteria. Workers with and without ectosymbionts cannot be discriminated based on cuticular odors. Some hydrocarbons found on the actinobacteria culture may be general for all bacteria membranes and may have contaminated the gelose. Hydrocarbon production is very low and most likely is not important compared to ant cuticle production, indicating that the ant cuticular hydrocarbons do not originate from the actinobacteria. Nevertheless, actinobacteria also produce some hydrocarbons that may be a signal for recognition by ants, as Zhang et al. (2007) have recently shown that workers are able to recognize their own bacterial strain.