3). We then investigated whether Belinostat chemical structure the bacterial infection interfered with ovary activation in the beebread-fed queenless bees. Infection indeed impaired ovary activation, as was shown by a significantly lower number of bees with activated ovaries compared to the non-infected bees on this same diet (Fig.

3, insert). To investigate whether the effects of nutrition and infection extended to other reproduction-related genes (in addition to storage protein and receptor genes), we analyzed the vasa transcripts levels in the bees fed on different diets and challenged with S. marcescens. Significantly higher vasa transcripts levels were observed in the bees fed beebread than in those fed the other diets ( Fig. 4). Like observed for the vg, vgR, and hex 70a genes, bacterial infection impaired the increase in vasa transcript levels in the beebread-fed selleckchem bees ( Fig. 4). In the present study, we explored the costs of bacterial infection on gene transcription, protein storage and ovary activation in honey bee workers in relation to the type of the supplied diet. In a previous study (Lourenço et al., 2009), we used injection rather than oral administration to bacterially infect bees and then analyzed vg and hex 70a expression at 12 h post-infection. The transcript and protein-level responses to bacterial injection

were not distinguishable from those caused by water injection (injury). In the present work, the injury effect was circumvented by orally administering the bacteria via the diet. In addition, we extended the duration of the experiments (to 6 and 9 days) and considered additional parameters, i.e., nutrition and ovary status (activated or non-activated). Three other genes (vgR, apoLpR and vasa) were also investigated in the current study. Notably, the cost of infection on transcription and protein levels was mostly evident in the beebread-fed bees. In these bees, the transcription of vg, vgR, hex 70a and vasa, and the levels of Vg and Hex 70a proteins, were clearly impaired by the infection. These results indicate

that the physiological cost of infection is better evidenced under certain dietary conditions. Furthermore, the dynamic process of Vg storage (in hemolymph) and mobilization (to the fat body) may have been disrupted since the expression of vgR was inhibited in beebread-fed tuclazepam bees as a consequence of the infection. Royal jelly, like beebread, is a rich source of proteins for bees. It might be thought that the proportion of royal jelly in the diet was insufficient to allow increased levels of vg, vgR, hex 70a and vasa transcripts, and the Vg and Hex 70a proteins. Alternatively, the diet could have provided an excess of royal jelly and caused adverse effects on transcription. It is known that high levels of dietary protein consumption negatively correlate with survival in young worker honey bees ( Pirk et al., 2010).