The Grooming Invitation Dance of the Honey Bee

The grooming invitation dance is a striking behavior in honey bee colonies that has not been extensively studied. The objectives of this study were (1) to describe the dance through video analysis, (2) to test the functional hypothesis that it is a grooming solicitation signal, and (3) to analyze the stimuli that cause its production. A worker bee producing the grooming invitation dance stands stationary and vibrates her whole body from side‐to‐side at a frequency of 4.2 ± 0.2 Hz for 9.3 ± 1.0 s. Sometimes the bee mixes bouts of body vibration with brief bouts of self‐grooming (average duration = 1.4 s). Bees that perform the grooming invitation dance have a far higher probability of being quickly groomed by a nest mate than do bees that do not perform the dance. Bees that had chalk dust puffed onto the bases of their wings produced significantly more grooming invitation dances than did control bees that received only puffs of air. This shows that it may be the accumulation of small particles at the bases of the wings that normally triggers the dance. We suggest that the evolutionary origin of this signal is self‐grooming behavior.     

Direct Visual Observation of Wing Movements during the Honey Bee Waggle Dance

Recruitment-related behaviours such as waggle dances enable honey bee foragers to inform their nestmates about the location of important resources. However, it is still not known how the information contained in a dance performed in the darkness of the nest is transferred to followers. Although, there are findings indicating that dancing honey bees produce airborne sounds which may convey the information, there has only been indirect evidence that moving wings are the source of these airborne sounds. In this study, honey bee dances were recorded using a high-speed camera in order to directly observe and precisely measure the frequency of wing beats and abdomen wags of dancers. Dancing bees moved their wings for 40.4% of the duration of a waggle run and for only 8.1% of the duration of a circle run. The episodes of wing movements consisted of one to five wing beats and were separated by intervals of motionless wings. The mean frequency of wing beats was 167.0 Hz and significantly differed depending on the number of wing beats in one episode (p < 0.001) and the position of the wings (p = 0.007). The mean frequency of abdomen wags was 14.6 Hz. The mean number of followers was 7.9 and significantly more of them gathered around the abdomens of dancers than around their heads and thoraxes (p = 0.001). The results of this study support the assumption that moving wings are the source of airborne sounds emitted during honey bee dances.     

Foreword: Expression Profiling Within the Central Nervous System II

Neurochemical Research -     

Reactive Oxygen Species and the Central Nervous System

Radicals are species containing one or more unpaired electrons, such as nitric oxide (NO.). The oxygen radical superoxide (O2.-) and the nonradical hydrogen peroxide (H2O2) are produced during normal metabolism and perform several useful functions. Excessive production of O2.- and H2O2 can result in tissue damage, which often involves generation of highly reactive hydroxyl radical (.OH) and other oxidants in the presence of "catalytic" iron or copper ions. An important form of antioxidant defense is the storage and transport of iron and copper ions in forms that will not catalyze formation of reactive radicals. Tissue injury, e.g., by ischemia or trauma, can cause increased metal ion availability and accelerate free radical reactions. This may be especially important in the brain because areas of this organ are rich in iron and CSF cannot bind released iron ions. Oxidative stress on nervous tissue can produce damage by several interacting mechanisms, including increases in intracellular free Ca2+ and, possibly, release of excitatory amino acids. Recent suggestions that free radical reactions are involved in the neurotoxicity of aluminum and in damage to the substantia nigra in patients with Parkinson's disease are reviewed. Finally, the nature of antioxidants is discussed, it being suggested that antioxidant enzymes and chelators of transition metal ions may be more generally useful protective agents than chain-breaking antioxidants. Careful precautions must be used in the design of antioxidants for therapeutic use.     

Tissue Profiling of the Mammalian Central Nervous System Using Human Antibody-based Proteomics

A need exists for mapping the protein profiles in the human brain both during normal and disease conditions. Here we studied 800 antibodies generated toward human proteins as part of a Human Protein Atlas program and investigated their suitability for detailed analysis of various levels of a rat brain using immuno-based methods. In this way, the parallel, rather limited analysis of the human brain, restricted to four brain areas (cerebellum, cerebral cortex, hippocampus, and lateral subventricular zone), could be extended in the rat model to 25 selected areas of the brain. Approximately 100 antibodies (12%) revealed a distinct staining pattern and passed validation of specificity using Western blot analysis. These antibodies were applied to coronal sections of the rat brain at 0.7-mm intervals covering the entire brain. We have now produced detailed protein distribution profiles for these antibodies and acquired over 640 images that form the basis of a publicly available portal of an antibody-based Rodent Brain Protein Atlas database (www.proteinatlas.org/rodentbrain). Because of the systematic selection of target genes, the majority of antibodies included in this database are generated against proteins that have not been studied in the brain before. Furthermore optimized tissue processing and colchicine treatment allow a high quality, more extended annotation and detailed analysis of subcellular distributions and protein dynamics.The brain is the most complex organ in the mammalian body. It processes sensory information from our external environment; produces behavior, emotions, and memories; and regulates the internal body homeostasis. To fulfill these diverse functions the brain harbors a myriad of neuronal networks processing information and connecting input and output systems. Because of the highly specialized functions, each neuron population is neurochemically specified expressing the necessary sets of proteins. Consequently a large number of genes are expressed in the mammalian brain. Based on microarray and in situ hybridization studies it is estimated that ∼55–80% of all mouse genes are expressed in the brain (1, 2) (gene expression during developmental stages and pathological conditions not included). Interestingly 70% of these genes are expressed in different cell populations each covering less than 20% of the brain, indicating the complexity of the brain and the specialization of individual populations of neurons (1).The success of humans as a species relies on our mental abilities, a result of brain development during evolution. The human brain is distinguished from other mammalian brains by its size; especially the neocortex involved in higher cognitive functions is greatly enlarged in humans. Despite this difference, the human brain has many similarities to brains of other mammalian species, and to some extent mammalian brains have a well preserved basic architecture (basic uniformity) (for reviews, see Refs. 3 and 4). Therefore, most human brain nuclei and connections have orthologs in other mammalian species ranging from great apes to rodents.Genetic variation underpins interspecies variation in gene expression and assembly of proteins. The human and rat genomes encode similar numbers of genes of which the majority have persisted throughout evolution without deletion or duplication (5). It is evident that small changes in protein structure and altered expression levels of proteins influence brain development and form the basis of interspecies differences. However, most human genes have orthologs in rodents, and for most cell types in the brain their neurochemical specification has been preserved throughout evolution. Because of genomic homology and similarity in basic layout of the mammalian brain as well as the preservation of neurochemical specification of subsets of neurons throughout evolution, animal models have shown their value in medical neurosciences (6).Advances in science are largely dependent on the processing of available information and the generation of new concepts and are driven by innovation and availability of new technologies. Recently mRNA-based techniques have emerged as an effective tool for genome wide analysis of expression levels in entire organs or disease-affected tissue. Results obtained from these studies are a source for identification of novel key molecules and have a predictive value to estimate changes in protein synthesis. There are several ongoing initiatives focusing on the expression profiles of the mammalian brain. The Allen Brain Atlas has produced detailed in situ hybridization profiles for over 20,000 genes in the mouse brain (1). The Gene Expression Nervous System Atlas (GENSAT) project uses enhanced green fluorescent protein reporter genes incorporated into bacterial artificial chromosome transgenic mice to visualize the expression profiles of the most important genes (7). This strategy can result in the identification of expressing cell types as the detailed morphology of enhanced green fluorescent protein-expressing cells is apparent. The Brain Maps project has a large collection of mammalian and non-mammalian brain maps using “classical” histochemical techniques but also includes a few protein distribution profiles visualized using immunohistochemistry (8).We previously described the possibilities of using antibodies raised against human proteins on rodent brain tissue (9). Here we show the first efforts to produce detailed proteome wide large scale tissue profiling maps of a mammalian brain using an antibody-based proteomics approach. In addition to the available, mentioned information on mRNA levels (Allen Brain Atlas), gene expression profiles (Gene Expression Nervous System Atlas), and detailed neuroanatomy (Brain Maps), antibody-based proteomics provide new information on cellular and subcellular distribution of gene products. This information will increase general knowledge and understanding of the organization and functioning of the brain. The study is based on antibodies generated as part of the Human Protein Atlas program aimed at exploring the protein expression patterns in normal and cancer tissues using tissue microarray-based immunohistochemistry and fluorescence-based confocal microscopy (10).The Human Proteome Resource center aims to produce monospecific antibodies against every human gene. So far, the distribution profiles of 3,000 proteins in 48 human tissues, including four brain areas (cerebellum, cerebral cortex, the hippocampal formation, and lateral subventricular zone), and 20 cancers are available (Human Protein Atlas). The antibodies generated within the framework of this program are based on antigens selected as unique regions for each individual protein, called protein epitope signature tags (PrESTs)¹ (11, 12). Over 5,000 antibodies have been generated and validated using Western blot analysis and protein arrays (13). The smaller size of the rat brain allows analysis of many brain areas and exposure of the antibodies to a very wide variety of proteins. Furthermore tissue can be processed under perfect conditions optimizing tissue antigenicity with flawless tissue morphology.Here we describe the initial large scale mapping of 89 protein distribution profiles in 25 selected rat brain areas. By exposing systematically sampled rat brain tissue to our collection of monospecific antibodies a more detailed protein atlas of the mammalian brain was produced, expanding the four brain areas available in the human protein atlas to 25 brain areas (Fig. 1) involved in higher cognitive functions, sensation, emotion, maintenance of internal homeostasis, sleep, and motor and sexual behaviors. A database portal has been created to show selected images from the various regions of the brain.Open in a separate windowFig. 1.Schematic overview of the 25 selected brain areas. Included are telencephalon (medial septum, lateral septum, horizontal/vertical diagonal band, prefrontal/cingulate/somatosensory/piriform/entorhinal cortex, ventral pallidum, stria terminalis, globus pallidus, caudate putamen, amygdala (basolateral, central, and medial), hippocampus, and dentate gyrus); diencephalon (preoptic area (A), supraoptic nucleus (A), suprachiasmatic nucleus (A), paraventricular nucleus (A and B), arcuate nucleus (B), median eminence (B), and thalamus); mesencephalon (substantia nigra, ventral tegmental area, and raphe nucleus (dorsal and median)); pons (locus caeruleus (C)); and cerebellum.     

Prologue: Expression Profiling Within the Central Nervous System,Part II

Neurochemical Research -     

Foreword: Special Issue on Expression Profiling Within the Central Nervous System

Neurochemical Research -     

The Honey Bee Pathosphere of Mongolia: European Viruses in Central Asia

Parasites and pathogens are apparent key factors for the detrimental health of managed European honey bee subspecies, Apis mellifera. Apicultural trade is arguably the main factor for the almost global distribution of most honey bee diseases, thereby increasing chances for multiple infestations/infections of regions, apiaries, colonies and even individual bees. This imposes difficulties to evaluate the effects of pathogens in isolation, thereby creating demand to survey remote areas. Here, we conducted the first comprehensive survey for 14 honey bee pathogens in Mongolia (N = 3 regions, N = 9 locations, N = 151 colonies), where honey bee colonies depend on humans to overwinter. In Mongolia, honey bees, Apis spp., are not native and colonies of European A. mellifera subspecies have been introduced ~60 years ago. Despite the high detection power and large sample size across Mongolian regions with beekeeping, the mite Acarapis woodi, the bacteria Melissococcus plutonius and Paenibacillus larvae, the microsporidian Nosema apis, Acute bee paralysis virus, Kashmir bee virus, Israeli acute paralysis virus and Lake Sinai virus strain 2 were not detected, suggesting that they are either very rare or absent. The mite Varroa destructor, Nosema ceranae and four viruses (Sacbrood virus, Black queen cell virus, Deformed wing virus (DWV) and Chronic bee paralysis virus) were found with different prevalence. Despite the positive correlation between the prevalence of V. destructor mites and DWV, some areas had only mites, but not DWV, which is most likely due to the exceptional isolation of apiaries (up to 600 km). Phylogenetic analyses of the detected viruses reveal their clustering and European origin, thereby supporting the role of trade for pathogen spread and the isolation of Mongolia from South-Asian countries. In conclusion, this survey reveals the distinctive honey bee pathosphere of Mongolia, which offers opportunities for exciting future research.     

Age-Related Changes of Ribonuclease Activities in Various Regions of the Rat Central Nervous System

Acid (pH 5.5), free, and latent alkaline (pH 7.4) RNases were assayed in homogenates of temporal cortex, hypothalamus, hippocampus, and cervicothoracic segments of spinal cord of rats at three different ages (5, 14, and 25 months old). Free alkaline RNase activity was lower (two- to fivefold) than the acid activity. Both free and inhibitor-bound alkaline RNases remained unchanged with age in all CNS regions examined. This result also indirectly indicates no change of RNase-inhibitor complex throughout aging. In contrast, the acid RNase activity showed a significant increase during aging in all tissues, with exception of the hypothalamus. Because this enzyme is localized mainly in the lysosomes, this result might be due to an increased lysosomal activity and/or to the release of hydrolases into the cytoplasm from these organelles, undergoing shrinkage and degeneration in aged animals.     

A Game Theoretical Analysis of the Mating Sign Behavior in the Honey Bee

Queens of the honey bee, Apis mellifera (L.), exhibit extreme polyandry, mating with up to 45 different males (drones). This increases the genetic diversity of their colonies, and consequently their fitness. After copulation, drones leave a mating sign in the genital opening of the queen which has been shown to promote additional mating of the queen. On one hand, this signing behavior is beneficial for the drone because it increases the genetic diversity of the resulting colony that is to perpetuate his genes. On the other hand, it decreases the proportion of the drone??s personal offspring among colony members which is reducing drone fitness. We analyze the adaptiveness and evolutionary stability of this drone??s behavior with a game-theoretical model. We find that theoretically both the strategy of leaving a mating sign and the strategy of not leaving a mating sign can be evolutionary stable, depending on natural parameters. However, the signing strategy is not favored for most scenarios, including the cases that are biologically plausible in reference to empirical data. We conclude that leaving a sign is not in the interest of the drone unless it serves biological functions other than increasing subsequent queen mating chances. Nevertheless, our analysis can also explain the prevalence of such a behavior of honey bee drones by a very low evolutionary pressure for an invasion of the nonsigning strategy.     

Down-Regulation of Honey Bee IRS Gene Biases Behavior toward Food Rich in Protein

Food choice and eating behavior affect health and longevity. Large-scale research efforts aim to understand the molecular and social/behavioral mechanisms of energy homeostasis, body weight, and food intake. Honey bees (Apis mellifera) could provide a model for these studies since individuals vary in food-related behavior and social factors can be controlled. Here, we examine a potential role of peripheral insulin receptor substrate (IRS) expression in honey bee foraging behavior. IRS is central to cellular nutrient sensing through transduction of insulin/insulin-like signals (IIS). By reducing peripheral IRS gene expression and IRS protein amount with the use of RNA interference (RNAi), we demonstrate that IRS influences foraging choice in two standard strains selected for different food-hoarding behavior. Compared with controls, IRS knockdowns bias their foraging effort toward protein (pollen) rather than toward carbohydrate (nectar) sources. Through control experiments, we establish that IRS does not influence the bees'' sucrose sensory response, a modality that is generally associated with food-related behavior and specifically correlated with the foraging preference of honey bees. These results reveal a new affector pathway of honey bee social foraging, and suggest that IRS expressed in peripheral tissue can modulate an insect''s foraging choice between protein and carbohydrate sources.     

Glycine,Serine, and Leucine Metabolism in Different Regions of Rat Central Nervous System

We have investigated the glycine, serine and leucine metabolism in slices of various rat brain regions of 14-day-old or adult rats, using [1-¹⁴C]glycine, [2-¹⁴C]glycine, L-[3-¹⁴C]serine and L-[U-¹⁴C]leucine. We showed that the [1-¹⁴C]glycine oxidation to CO₂ in all regions studied occurs almost exclusively through its cleavage system (GCS) in brains of both 14-day-old and adults rats. In 14-day-old rats, the highest oxidation of [1-¹⁴C]glycine was in cerebellum and the lowest in medulla oblongata. In these animals, the L-[U-¹⁴C]leucine oxidation was lower than the [1-¹⁴C]glycine oxidation, except in medulla oblongata where both oxidations were the same. Serine was the amino acid that showed lowest oxidation to CO₂ in all structure studied. In adult rats brains, the highest oxidation of [1-¹⁴C]glycine was in cerebral cortex and the lowest in medulla oblongata. We have not seen difference in the lipid synthesis from both glycine labeled, neither in 14-day-old rats nor in adult ones, indicating that the lipids formed from glycine were not neutral. Lipid synthesis from serine was significantly high than lipid synthesis and from all other amino acids studied in all studied structures. Protein synthesis from L-[U-¹⁴C]leucine was significantly higher than that from glycine in all regions and ages studied.     

Microbial Communities of Three Sympatric Australian Stingless Bee Species

Bacterial symbionts of insects have received increasing attention due to their prominent role in nutrient acquisition and defense. In social bees, symbiotic bacteria can maintain colony homeostasis and fitness, and the loss or alteration of the bacterial community may be associated with the ongoing bee decline observed worldwide. However, analyses of microbiota associated with bees have been largely confined to the social honeybees (Apis mellifera) and bumblebees (Bombus spec.), revealing – among other taxa – host-specific lactic acid bacteria (LAB, genus Lactobacillus) that are not found in solitary bees. Here, we characterized the microbiota of three Australian stingless bee species (Apidae: Meliponini) of two phylogenetically distant genera (Tetragonula and Austroplebeia). Besides common plant bacteria, we find LAB in all three species, showing that LAB are shared by honeybees, bumblebees and stingless bees across geographical regions. However, while LAB of the honeybee-associated Firm4–5 clusters were present in Tetragonula, they were lacking in Austroplebeia. Instead, we found a novel clade of likely host-specific LAB in all three Australian stingless bee species which forms a sister clade to a large cluster of Halictidae-associated lactobacilli. Our findings indicate both a phylogenetic and geographical signal of host-specific LAB in stingless bees and highlight stingless bees as an interesting group to investigate the evolutionary history of the bee-LAB association.     

Vimentin in the Central Nervous System

Intermediate filament proteins were identified by two-dimensional gel electrophoresis in urea extracts of rat optic nerves undergoing Wallerian degeneration and in cytoskeletal preparations of rat brain and spinal cord during postnatal development. The glial fibrillary acidic (GFA) protein and vimentin were the major optic nerve proteins following Wallerian degeneration. Vimentin was a major cytoskeletal component of newborn central nervous system (CNS) and then progressively decreased until it became barely identifiable in mature brain and spinal cord. The decrease of vimentin occurred concomitantly with an increase in GFA protein. A protein with the apparent molecular weight of 61,000 and isoelectric point of 5.6 was identified in both cytoskeletal preparations of brain and spinal cord, and in urea extracts of normal optic nerves. The protein disappeared together with the polypeptides forming the neurofilament triplet in degenerated optic nerves.     

Vast Differences in Strain-Level Diversity in the Gut Microbiota of Two Closely Related Honey Bee Species

1. Download : Download high-res image (191KB)
2. Download : Download full-size image

     

Central Nervous System Manifestations of Chickenpox

A study of 57 cases of affection of the central nervous system associated with chickenpox diagnosed and treated at The Hospital for Sick Children in Toronto between 1956 and 1967, inclusive, is presented. The commonest type, the cerebellar variety (50%), had an excellent prognosis. In the next commonest, the cerebral type (40%), the mortality rate was 35% but there was a low incidence of permanent sequelae in the surviving patients. A small group classed as aseptic meningitis was defined and one case of myelitis was reviewed.     

A Study of Polymorphisms in Three Loci Known to Influence Defensive Behavior Using PCR-SSCP and Direct Sequencing in the Iranian Honey Bee Population

Polymerase Chain Reaction (PCR) and subsequent separation of PCR products on polyacrylamide gels to find Single Stranded Conformation Polymorphisms (SSCP) was used for three loci, known from studies in North America to affect defensive behavior (Quantitative Trait Loci (QTL) sting1–3), on samples of Iranian honey bee (Apis mellifera L.). In the present study these loci were amplified with specific primers for sting1–3. The analysis of these loci using SSCP, created different patterns among samples. The polymorphisms observed in this study of the Iranian population of honey bees are a first step toward the eventual implementation of a genetic marker-based selection program to reduce defensive behavior. Now, because of this study, the markers are available to conduct more research so that the association of these polymorphic loci and aggressive traits in the Iranian honey bee population can be determined.