Transcription profiling of brains of 10 day old virgin queen, sterile worker, and reproductive worker honey bees
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ABSTRACT: We used microarrays to monitor expression patterns of several thousand genes in the brains of same-aged (10 day old) virgin queens, sterile workers, and reproductive workers in honey bees (Apis mellifera).
Project description:This experiment compared gene expression in individual brains of field collected Polistes metricus in four adult behavioral states: solitary foundresses, foraging workers, queens, and pre-overwintering gynes.
Project description:Mating is fundamental to the success and reproduction of most organisms, although the physiological and transcriptional changes associated with this process have been largely characterized only in Drosophila. In this study, we use honey bees as a model system since their queens undergo massive and permanent physiological and behavioral changes following mating. Previous studies have identified changes associated with the transition from a virgin queen to a fully-mated, egg-laying queen. Here, we further uncouple the mating process to examine the effects of natural mating vs. instrumental insemination and saline vs. semen insemination. We observed significant overlap between our study and analogous studies in Drosophila, suggesting that some post-mating mechanisms are conserved across insect orders.
Project description:In honey bees (Apis mellifera), the reproductive queen produces a pheromonal signal that regulates many aspects of worker behavior and physiology and is critical for maintaining colony organization. Queen mandibular pheromone (QMP) inhibits worker reproduction, attracts workers from a short distance (retinue response), inhibits the rearing of new queens, modulates age-related division of labor and globally alters brain gene expression in worker bees. Interestingly, substantial variation in worker retinue responses to QMP has been found between colonies, but the molecular and physiological bases for variation in individual responses to the queen have not been characterized. Here, we demonstrate that individual retinue response is negatively correlated with traits associated with reproductive potential. Workers with low response to QMP have more ovarioles and higher levels of vitellogenin transcripts than workers with a high response to QMP, suggesting that workers with greater reproductive potential may be attempting to escape queen control. Retinue response appears to be associated with a suite of behavioral and physiological traits that may be pleiotropically linked. However, while these phenotypes are all correlated at the organismal level, the underlying brain expression patterns and gene networks associated with each trait are independent, suggesting that these phenotypes are uncoupled at the molecular level in adult bees. These studies provide insights into the ultimate and proximate causes of natural variation in pheromone response in honey bees.
Project description:We characterized and compared hemolymph proteome of Royal Jelly bees (RJbs), a stock selected for increasing RJ output from Italian bees (ITbs) and ITbs across the larval and adult ages. Unprecedented depth of proteome was attained by identifying 3394 hemolymph proteins in both bee lines. The proteome supports the general function of hemolymph to drive development and immunity across different phases in both bees. However, age-specific proteome settings have adapted to prime the distinct physiology for larvae and adult bees. In larvae, proteome are thought to drive the temporal immunity, rapid organogenesis, and reorganization of larval structures. In adults, proteome play key roles to prompt tissues development and immune defense in NEBs, glands maturity in NBs and carbohydrate energy production in FBs. Comparing the proteome between the same aged larval and adult samples, RJbs and ITbs have tailored distinct hemolymph proteome programs to drive their physiology. Particularly, in day 4 larvae and NBs, a large number of highly abundant proteins enriched in protein synthesis and energy metabolism in RJbs relative to ITbs imply that RJb larvae and NBs have reprogrammed their proteome to initiate different developmental trajectory and high RJ secretion in response to the enhanced RJ production by selection. Our hitherto depth of proteome coverage gains novel sight on molecular details in driving hemolymph function and high RJ production by RJbs.
Project description:Complemented carm1-/- MEFs with CARM1 wt were left untreated or were stimulated for 3hours with 10ng/ml mTNFa. mTNFa-induced NF-kB dependent gene expression was analyzed on a custom array for specific NF-kB target genes
Project description:This experiment examines gene expression profiles in individual honey bee brains (adult worker Apis mellifera). The purpose is to test whether behavioral phenotype can be predicted by expression profiles in individual brains in a naturalistic context (i.e., colonies in the field). The two behavioral phenotypes examined are 'nurse' and 'forager'. Other factors examined are age, genotype (full-sister group), and colony environment.<br><br> An additional processed data file is available on the FTP site for this experiment.
Project description:As a matter of fact, honeybees are vital for the pollination of more than 80 crops of agricultural interest. However, population decline has become an important global issue causing significant concerns among agricultural experts and the broader public. For this, parasites are known to be the major culprits responsible for the losses of millions of honeybee colonies so far. Among these parasites, Varroa destructor has been identified as a major cause for global losses in Western honeybee (Apis mellifera) colonies. Hygienic behavior (HB), on the other hand, is a collective response by adult honeybees to defend against parasites and diseases that is known to involve in resistance towards Varroosis. Even with the efforts made to elucidate the molecular mechanism underlying HB, it is still not understood. In our study, we have studied the proteomic correlates to HB using a honeybee line (selected for Varroa-specific HB for over a decade in Germany). We sampled individual worker bees from this line that showed HB after closer infrared video observations and compared the proteomes of their mushroom bodies and antennae with those of workers that came from the same set of colonies but didn't show the behaviour. Furthermore, we compared the pupal hemolymph for worker bees of the selected HB line and a control line using state-of-the art techniques of proteomics. We identified a total of 8609 proteins (covered >55% of the honeybee proteome) from these three honeybee tissues. This is the most comprehensive proteomic study of the honeybee HB to date, and the first to focus on individual bees expressing Varroa-specific HB. These results have significantly advanced our knowledge on the biology underlining HB to a new level. The uniquely found functional classes and pathways by the proteins identified in each tissue suggest that hygienic bees have shaped distinct proteome settings to underpin the HB. Moreover, during analysis of pupal hemolymph proteome, the HB-line has adapted a unique strategy to boost an individual and social immunity and drove pupal organogenesis via energy metabolism and protein biosynthesis. Moreover, in the mushroom bodies of different HB phenotypic worker bees, the hygienic bees have enhanced their neuronal sensitivity to promote the execution of HB by activation of synaptic vesicles and calcium channel activities. Moreover, in the antennae of two HB phenotypic worker bees, the hygienic bees have demonstrated strengthening of their sensitivity associated with olfactory senses and signal transmissions, which is important to input a strong signal to the mushroom bodies and initiate HB. In conclusion, our novel findings have significantly extended our understandings of the molecular mechanisms that underline the HB to combat Varroa infestation. Furthermore, we identified a wide array of novel markers that are useful for accelerating marker associated selection of HB to aid in the natural resistance to a parasite blamed for a global decline in honeybee health.
Project description:BACKGROUND: Social insects, such as honey bees, use molecular, physiological and behavioral responses to combat pathogens and parasites. The honey bee genome contains all of the canonical insect immune response pathways, and several studies have demonstrated that pathogens can activate expression of immune effectors. Honey bees also use behavioral responses, termed social immunity, to collectively defend their hives from pathogens and parasites. These responses include hygienic behavior (where workers remove diseased brood) and allo-grooming (where workers remove ectoparasites from nestmates). We have previously demonstrated that immunostimulation causes changes in the cuticular hydrocarbon profiles of workers, which results in altered worker-worker social interactions. Thus, cuticular hydrocarbons may enable workers to identify sick nestmates, and adjust their behavior in response. Here, we test the specificity of behavioral, chemical and genomic responses to immunostimulation by challenging workers with a panel of different immune stimulants (saline, Sephadex beads and Gram-negative bacteria E. coli). RESULTS: While only bacteria-injected bees elicited altered behavioral responses from healthy nestmates compared to controls, all treatments resulted in significant changes in cuticular hydrocarbon profiles. Immunostimulation caused significant changes in expression of hundreds of genes, the majority of which have not been identified as members of the canonical immune response pathways. Furthermore, several new candidate genes that may play a role in cuticular hydrocarbon biosynthesis were identified. Finally, we identified common genes regulated by pathogen challenge in honey bees and other insects, suggesting that immune responses are conserved at the molecular level. CONCLUSIONS: These studies suggest that honey bee genomic responses to immunostimulation are substantially broader than expected, and may mediate the behavioral changes associated with social immunity by orchestrating changes in chemical signaling.
Project description:Responses to social cues, such as pheromones, can be modified by genotype, physiology, or environmental context. Honey bee queens produce a pheromone (queen mandibular pheromone; QMP) which regulates many aspects of worker bee behavior and physiology. Forager honey bees are less responsive to QMP than young nurse bees engaged in brood care, suggesting that physiological changes associated with behavioral maturation may modulate response to this pheromone. Since cGMP is a major regulator of behavioral maturation in honey bee workers, we examined its role in modulating worker responses to QMP. Treatment with a cGMP analog, 8-Br-cGMP, resulted in significant reductions in both behavioral and physiological responses to QMP in young caged workers. Treatment significantly reduced attraction to QMP (the retinue response) and inhibited the QMP-mediated increase in vitellogenin levels in the fat bodies of worker bees. Genome-wide analysis of brain gene expression patterns demonstrated that cGMP has a larger effect on expression levels than QMP, and that QMP has specific effects in the presence of cGMP, suggesting that some responses to QMP may be dependent on an individual beesM-^R physiological state. Several functional gene categories were significantly differentially expressed, including genes involved in regulating GTPase activity, phototransduction, immunity, and carboxylic acid transmembrane transporter activity. Overall, our data suggest that cGMP-mediated processes play a large role in modulating responses to queen pheromone in honey bees, at the behavioral, physiological and molecular levels.