Transcription profiling of brain from honey bees treated with brood pheromone
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ABSTRACT: Expression profiling of honey bee brains exposed to brood pheromone. Exposure was performed in colonies and young (5 days-old) and old bees (15 days-old) were analyzed .
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:We analyzed the changes in brain gene expression after alarm pheromone exposure. Bees from single-drone inseminated colonies were exposed to alarm pheromone at the hive entrance and collected 1h after exposure for analysis.
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:Sibling care is a hallmark of the social insects, but its evolution remains challenging to explain. The hypothesis that sibling care evolved from ancestral maternal care in the primitively eusocial insects has been elaborated to involve heterochronic changes in gene expression. This elaboration leads to the prediction that workers in these species will show patterns of gene expression more similar to foundress queens, who express maternal care behavior, than to established queens engaged solely in reproductive behavior. We tested this idea in the bumblebee Bombus terrestris using a microarray platform with ca. 4,500 genes. Unlike in the wasp Polistes metricus, in which support for the above prediction has been obtained, we found that patterns of brain gene expression in foundress and queen bumblebees were more similar to each other than to workers. However, comparisons of lists of differentially expressed genes derived from this study and gene lists from microarray studies in Polistes and the honeybee Apis mellifera suggest that there is a shared set of genes involved in the regulation of related social behaviors across independent eusocial lineages. Together, these results suggest that the multiple independent evolutions of eusociality in the insects involved a combination of shared and different mechanisms.
Project description:Brain expression profiling of bees perfroming consistently vibration signal (modulatory signal that stimulates the performance of several different activities in the hive).
Project description:The aim of this work was to extend the previous gene expression analysis ofM- M- nurse and forager gene expression, but using the Apis oligo-array designed from the recently sequenced genome.M- M- This study included 28000 features which included ~11000 predicted genes.M- M- The intial study was done using a microarray design based on PCR products of 5500 features derived from an expressed sequence tag analysis of a brain cDNA library.M- M- The variables studied were age (young and old), cast (nurse and forager) and differential gene expression.
Project description:The genome of the western honey bee (Apis mellifera) harbours ten different major royal jelly protein genes (mrjp1-10) which originate from a single-copy precursor via gene duplication. The evolutionary fate of duplicated genes is eventually determined over time as to result in loss due to pseudogenization, or in preservation due to neo- or sub-functionalization. Both fates were already observed in the mrjp gene cluster, as only mrjp1 - 9 are expressed, whereas mrjp10 was pseudogenized and represents an incomplete gene copy. In contrast, MRJP1 underwent neofunctionalization and developed an essential function within the food jelly of queen larvae, to guaranty the survival of the whole colony. We here show combining quantitative real time PCR with quantitative mass spectrometry that expression of most mrjps (mrjp1-5 and 7) shows an age dependent pattern in worker hypopharyngeal glands as well as in brains. Expression increases after hatching until the nurse bee period and is followed by a decrease in older workers that forage for different plant products. Mrjp6 expression deviates considerably from the expression profiles of the other mrjps and transcript abundance does not correlate with protein amount. Thus, either mrjp6 does fulfil a total different function or it might be on its way to pseudogenization. Furthermore, a tissue-specific function of the proteins MRJP8 and 9 in the hypopharyngeal glands and the brain can be excluded, suggesting a more general physiological than a nutritive function for both gene products.