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PubMedDate not supplied

Microsphere entrapped bee-venom phospholipase A2 retains specific IgE binding capacity: a possible use for oral specific immunotherapy.

The only specific treatments of allergy are long and exacting desensitization by subcutaneous injections of the allergens. While oral administration of allergens could greatly facilitate these treatments, effective delivery systems are needed to prevent allergen degradation in the gastrointestinal tract and to enable their uptake by Peyer's patches. The potential for bee-venom phospholipase A2 (PLA2) to be used in such oral immunotherapy was tested. For this purpose, PLA2 potential alterations were analysed when encapsulated into poly(D,L-lactide-co-glycolide) microspheres by double emulsion solvent evaporation. It was shown that microencapsulation had only limited effects on the integrity of the entrapped PLA2, which retained its fully specific murine IgE binding capacity. Thus, PLA2 loaded microspheres could represent a potential delivery system for bee venom allergy-specific oral immunotherapy.

Allergens↗
PubMed1994

Severe derangement of the coagulation profile following multiple bee stings in a 2-year-old boy.

Occasionally, insect bites producing systemic complications are the reason for admission to paediatric intensive care. We report an interesting case of multiple bee stings in a 2-year-old boy. The boy, who was stung more than 200 times by honey bees, had a severely deranged coagulation profile with marked elevation of the hepatic enzymes. This complication has not been reported to date. Prompt intensive supportive care led to the child's total recovery.

Alanine Transaminase↗
PubMed2003

Molecular phylogenetics of allodapine bees, with implications for the evolution of sociality and progressive rearing.

Allodapine bees have long been regarded as providing useful material for examining the origins of social behavior. Previous researchers have assumed that sociality arose within the Allodapini and have linked the evolution of sociality to a transition from mass provisioning to progressive provisioning of brood. Early phylogenetic studies of allodapines were based on morphological and life-history data, but critical aspects of these studies relied on small character sets, where the polarity and coding of characters is problematic. We used nucleotide sequence data from one nuclear and two mitochondrial gene fragments to examine phylogenetic structure among nine allodapine genera. Our data set comprised 1506 nucleotide positions, of which 402 were parsimony informative. Maximum parsimony, log determinant, and maximum likelihood analyses produced highly similar phylogenetic topologies, and all analyses indicated that the tropical African genus Macrogalea was the sister group to all other allodapines. This finding conflicts with that of previous studies, in which Compsomelissa + Halterapis formed the most basal group. Changing the basal node of the Allodapini has major consequences for understanding evolution in this tribe. Our results cast doubt on the previous hypotheses that progressive provisioning and castelike social behavior evolved among lineages leading to the extant allodapine taxa. Instead, our results suggest that mass provisioning in Halterapis is a derived feature and that social behavior is an ancestral trait for all allodapine lineages. The forms of social behavior present in extant allodapines are likely to have resulted from a long evolutionary history, which may help explain the complexity of social traits found in many allodapine bees.

Africa↗
PubMed2000

A Cl(-) cotransporter selective for NH(4)(+) over K(+) in glial cells of bee retina.

There appears to be a flux of ammonium (NH(4)(+)/NH(3)) from neurons to glial cells in most nervous tissues. In bee retinal glial cells, NH(4)(+)/NH(3) uptake is at least partly by chloride-dependant transport of the ionic form NH(4)(+). Transmembrane transport of NH(4)(+) has been described previously on transporters on which NH(4)(+) replaces K(+), or, more rarely, Na(+) or H(+), but no transport system in animal cells has been shown to be selective for NH(4)(+) over these other ions. To see if the NH(4)(+)-Cl(-) cotransporter on bee retinal glial cells is selective for NH(4)(+) over K(+) we measured ammonium-induced changes in intracellular pH (pH(i)) in isolated bundles of glial cells using a fluorescent indicator. These changes in pH(i) result from transmembrane fluxes not only of NH(4)(+), but also of NH(3). To estimate transmembrane fluxes of NH(4)(+), it was necessary to measure several parameters. Intracellular pH buffering power was found to be 12 mM. Regulatory mechanisms tended to restore intracellular [H(+)] after its displacement with a time constant of 3 min. Membrane permeability to NH(3) was 13 microm s(-1). A numerical model was used to deduce the NH(4)(+) flux through the transporter that would account for the pH(i) changes induced by a 30-s application of ammonium. This flux saturated with increasing [NH(4)(+)](o); the relation was fitted with a Michaelis-Menten equation with K(m) approximately 7 mM. The inhibition of NH(4)(+) flux by extracellular K(+) appeared to be competitive, with an apparent K(i) of approximately 15 mM. A simple standard model of the transport process satisfactorily described the pH(i) changes caused by various experimental manipulations when the transporter bound NH(4)(+) with greater affinity than K(+). We conclude that this transporter is functionally selective for NH(4)(+) over K(+) and that the transporter molecule probably has a greater affinity for NH(4)(+) than for K(+).

Acid-Base Equilibrium↗
PubMed1976

Role of intracellular calcium and sodium in light adaptation in the retina of the honey bee drone (Apis mellifera, L).

In the honey bee drone, the decrease in sensitivity to light of a retinula cell exposed to background illumination was found to be accurately reflected by the difference in amplitude between the initial transient depolarization and the lowest steady depolarization evoked by the background light. It is shown that both the decrease in sensitivity to light and the accompanying drop in potential from the transient to the plateau can be prevented by injecting EGTA intracellularly. A decrease in duration and amplitude of responses to short test flashes such as observed immediately after illumination was found to occur too when Ca or Na, but not K, Li, or Mg injected into dark-adapted retinula cells. Injection of EGTA into a retinula cell maintained a steady state of light adaptation, was found to cause an increase in amplitude and duration of the response to a short test flash, thus producing the effects of dark adaptation. It is suggested that, in the retina of the honey bee drone, an increase in intracellular calcium concentration plays a central role in light adaptation and that an increase in intracellular sodium concentration, resulting from the influx of sodium ions during the responses to light, could lead to this increase in intracellular free calcium.

Adaptation, Ocular↗
PubMed2004

Different thresholds for detection and discrimination of odors in the honey bee (Apis mellifera).

Naturally occurring odors used by animals for mate recognition, food identification and other purposes must be detected at concentrations that vary across several orders of magnitude. Olfactory systems must therefore have the capacity to represent odors over a large range of concentrations regardless of dramatic changes in the salience, or perceived intensity, of a stimulus. The stability of the representation of an odor relative to other odors across concentration has not been extensively evaluated. We tested the ability of honey bees to discriminate pure odorants across a range of concentrations at and above their detection threshold. Our study showed that pure odorant compounds became progressively easier for honey bees to discriminate with increasing concentration. Discrimination is, therefore, a function of odorant concentration. We hypothesize that the recruitment of sensory cell populations across a range of concentrations may be important for odor coding, perhaps by changing its perceptual qualities or by increasing its salience against background stimuli, and that this mechanism is a general property of olfactory systems.

Animals↗
PubMed1995

Major quantitative trait loci affecting honey bee foraging behavior.

We identified two genomic regions that affect the amount of pollen stored in honey bee colonies and influence whether foragers will collect pollen or nectar. We selected for the amount of pollen stored in combs of honey bee colonies, a colony-level trait, and then used random amplified polymorphic DNA (RAPD) markers and interval mapping procedures with data from backcross colonies to identify two quantitative trait loci (pln1 and pln2, LOD 3.1 and 2.3, respectively). Quantitative trait loci effects were confirmed in a separate cross by demonstrating the cosegregation of marker alleles with the foraging behavior of individual workers. Both pln1 and pln2 had an effect on the amount of pollen carried by foragers returning to the colony, as inferred by the association between linked RAPD marker alleles, D8-.3f and 301-.55, and the individual pollen load weights of returning foragers. The alleles of the two marker loci were nonrandomly distributed with respect to foraging task. The two loci appeared to have different effects on foraging behavior. Individuals with alternative alleles for the marker linked to pln2 (but not pln1) differed with respect to the nectar sugar concentration of their nectar loads.

Animals↗
PubMed1975

Sex determination in bees. IV. Genetic control of juvenile hormone production in Melipona quadrifasciata (Apidae).

Cell number and volume of corpora allata was determined for 8 phases of development, the first prepupal stage to adults 30 days old, in the social Apidae Melipona quadrifasciata. In the second prepupal stage a strong correlation was found between cell number and body weight (r = 0.651), and cell number and corpora allata volume in prepupal stage (r = 0.535), which indicates that juvenile hormone has a definite role in caste determination in Melipona. The distribution of the volume of corpus allatum suggest a 3:1 segregation between bees with high volume of corpora allata against low and medium volume. This implies that genes kappa a and kappa b code for an enzyme that directly participates in juvenile hormone production. It was also concluded that the number of cells in the second prepupal stage is more important than the weight of the prepupa for caste determination. A scheme summarizing the genic control of sex and caste determination in Melipona bees in the prepupal phase is given.

Alleles↗
PubMed1980

The evolution of multiple mating behavior by honey bee queens (Apis mellifera L.).

A model is presented showing that natural selection operating at the individual level can adequately explain the evolution of multiple mating behavior by honey bee queens. Group selection need not be invoked. The fitness of a given female genotype is a function of the number of sex alleles in the population, the number of matings by an individual female and the specific parameters that determine the relationship of brood viability to individual fitness. Even though the exact relationship is not known, it is almost certainly not linear. A nonlinear relationship between worker brood viability and fitness and a significant genetic load associated with the sex-determination system in honey bees are the essential components of this model.

Animals↗
PubMed1999

On the diversity and heterogeneity of H-2(d)-restricted determinants and T cell epitopes from the major bee venom allergen.

One of the main limitations of using synthetic peptides for immunotherapy in allergic patients is the difficulty to delineate the immunodominant T cell epitopes which are necessarily dependent on HLA molecules. We have thus addressed the question of the role of MHC II molecules in immunodominant epitopes selection in the particular case of the major bee venom allergen (API m1). To exhaustively and easily explore it, we used BALB/c mice whose H-2 haplotype is associated with high IgE and IgG responses to API m1. By means of extensive sets of synthetic peptides, we investigated the specificity of polyclonal T cells and monoclonal hybridomas from mice immunized with API m1 and delineated four immunodominant regions, restricted to either the I-E(d) or the I-A(d) molecule. All the peptides were also tested for their capacity to bind to immunopurified MHC II molecules. Eight determinants of high affinity were identified. They clustered into three distinct regions and were largely overlapping. They included all the immunodominant epitopes, but half of them were not capable of stimulating T cells. Strikingly, interacting surfaces with either the TCR or MHC II molecule greatly differed from one determinant to another. In one case, we observed that flanking regions exerted a particular action on T cell stimulation which prevented the fine epitope localization. Our results underline the diversity and complexity of MHC II-restricted determinants and T cell epitopes from the major bee venom allergen, even in a single haplotype. These data also participate in the development of alternative approaches to conventional immunotherapy.

Allergens↗
PubMed1993

Epitope specificity of bee venom phospholipase A2-specific suppressor T cells which produce antigen-binding glycosylation inhibiting factor.

From the spleen cells of BALB/c mice primed with bee venom phospholipase A2 (PLA2), we established seven T cell hybridomas which constitutively secreted glycosylation inhibiting factor (GIF), expressed both CD3 and TCR alpha beta, and responded to antigen-pulsed antigen presenting cells (APC) for the formation of IgE-binding factor. Upon stimulation with antigen-pulsed APC, four of the seven hybridomas produced GIF having affinity for native PLA2. The antigen-binding GIF could suppress the anti-hapten antibody response of BALB/c mice to dinitrophenyl (DNP)-PLA2 conjugates in a carrier-specific manner and bound to immunosorbents coupled with either the mAb 14-12 or anti-TCR alpha chain, H28-710. Analysis of the epitope specificity of the TCR on the GIF-producing T hybridomas indicated that all of the hybridomas which could produce antigen-binding GIF upon antigenic stimulation recognized the synthetic peptide representing amino acid residues 19-34 in PLA2 molecules in the context of the product of the I-Ad subregion and the antigen-binding GIF formed by the cells had affinity for the peptide. The 3-D structure of bee venom PLA2 indicates that the sequence of amino acid 14-24 forms a loop in the PLA2 molecule and represents an external structure of the antigen, while peptide 25-37 forms an alpha helix. Evidence was obtained which suggests that the sequence of 25-34 contains amino acid residues interacting with Ia molecules, while peptide 19-24 contains residues involved in the interaction of p19-34-Ia complexes with TCR on the hybridomas. It was also found that not only the synthetic peptide 19-34, but also the peptides 13-28 and 19-30 inhibited the binding of antigen-binding GIF to PLA2-coupled Sepharose, while peptide 25-40 failed to do so. The results collectively indicate that the antigen-binding GIF and TCR on the cell source of the factor interact with a common epitope which is exposed on the surface of a nominal antigen.

Amino Acid Sequence↗
PubMed2004

Brood pheromone regulates foraging activity of honey bees (Hymenoptera: Apidae).

Brood pheromone modulated the foraging behavior of commercial honey bee, Apis mellifera L., colonies pollinating a 10-ha market garden of cucumber, Cucurbita pepo L., and zucchini, Cucumis saticus L., in Texas in late autumn. Six colonies were randomly selected to receive 2000 larval equivalents of brood pheromone and six received a blank control. The ratio of pollen to nonpollen foragers entering colonies was significantly greater in pheromone-treated colonies 1 h after treatment. Pheromone-treated foragers returned with pollen load weights that were significantly heavier than controls. Pollen returned by pheromone-treated foragers was 43% more likely to originate from the target crop. Number of pollen grains washed from the bodies of nonpollen foragers from pheromone-treated colonies was significantly greater than controls and the pollen was 54% more likely to originate from the target crop. Increasing the foraging stimulus environment with brood pheromone increased colony-level foraging and individual forager efforts. Brood pheromone is a promising technology for increasing the pollination activity and efficiency of commercial honey bee colonies.

Animals↗
PubMed2006

Human factors facilitating the spread of a parasitic honey bee in South Africa.

Workers of the honey bee subspecies Apis mellifera capensis (Eschscholtz) produce female offspring by thelytokous parthenogenesis and can parasitize colonies of other subspecies. In 1990, translocation of 400 colonies of A. m. capensis into the distribution area of A. m. scutellata by a commercial beekeeper triggered a dramatic parasitic phenomenon. Parasitized colonies died within a few months of infestation, and this resulted in the loss of tens of thousands of colonies by commercial beekeepers in the A. m. scutellata range in South Africa. To deal with the problem and to identify methods that would limit the impact of the social parasite, we investigated the link between beekeeping management and severity of parasitic infestations in terms of colony mortality and productivity. We demonstrate that colonies from apiaries subjected to migrations are very susceptible to infestation and consequently show dramatic mortality. Their productivity is also inferior to sedentary colonies and those in isolated apiaries in terms of honey yield and brood quantity. Furthermore, by concentrating hives in small areas and often in the vicinity of other beekeepers, cross-infestations can easily occur. This can undermine previously parasite-free beekeeping businesses. As a result of our surveys, we propose beekeeping practices based on locally trapped bees, reduced migration, and better control of parasite spread, thus promoting the conservation of these pollinators. If followed by all the South African beekeepers, these measures should limit the spread of the parasite until it is eliminated within a few years, after which full migratory beekeeping practices could resume.

Animal Husbandry↗
PubMed2006

Fine-scale genetic structure and fire-created habitat patchiness in the Australian allodapine bee, Exoneura nigrescens (Hymenoptera: Apidae).

Fire promotes an abundance of nest sites for the stem nesting bee Exoneura nigrescens, which remain viable for approximately 10 years. The finite duration of nesting substrate and localized fire events suggest that migration should minimize genetic structure among suitable habitat patches. Exoneura nigrescens was sampled from 7 localities with a known fire history in southwestern Victoria, Australia. Individual bees were genotyped at 8 microsatellite loci and genic and genotypic analyses applied to examine genetic structure among burn patch localities, within burn patches, and within colonies. Despite relatively short-term availability of nesting substrates, remarkably fine-scale genetic structure was observed both among burn patches and within burn patches. The spatial distribution of relatedness shows a strong pattern of isolation-by-distance at geographic distances to 35 km, suggesting that genetic partitioning among burn patches is, at least in part, a result of dispersal ability. Genetic structure within burn patches includes colonies consisting of close kin with genic partitioning among nests. Relatedness structure within colonies suggests that polygamy, multiple breeding pairs, and a lack of inbreeding typifies the mating system.

Animals↗
PubMed2004

Recent intron gain in elongation factor-1alpha of colletid bees (Hymenoptera: Colletidae).

We discovered the presence of a unique spliceosomal intron in the F1 copy of elongation factor-1alpha (EF-1alpha) restricted to the bee family Colletidae (Hymenoptera: Apoidae). The intron ranges in size from 101 to 1044 bp and shows no positional sliding. Our data also demonstrate the complete absence of this intron from exemplars representing all other bee families, as well as from close hymenopteran relatives. A review of the literature finds that this intron is likewise absent from all other arthropods for which data are available. This provides unambiguous evidence for a relatively recent intron insertion event in the colletid common ancestor and, at least in this specific instance, lends support to the introns-late hypothesis. The comparative distribution of this novel intron also supports the monophyly of Colletidae and the exclusion of the Stenotritidae from this family, providing an example of the potential of some introns to act as robust markers of shared descent.

Amino Acid Sequence↗
PubMedDate not supplied

Mosaic male honey bees produced by queens inseminated with frozen spermatozoa.

Mosaic male honey bees were found as the progeny of queens that had been inseminated with spermatozoa stored in liquid nitrogen. The origins of these mosaics and the genotype of their gametes were determined by using mutant markers. The mosaics probably developed from an egg pronucleus and a sperm pronucleus that did not unite after the latter had entered the egg. Instead, both pronuclei produced haploid tissue independently. The three mosaics that were mated to queens all had mosaic testes. Therefore, these were situations in which a male honey bee produced two types of spermatozoa.

Animals↗
PubMed1988

Should x-rays be ordered to find a bee's stinger?

On several occasions, we have been asked to locate bee stingers so that they could be removed. The studies were negative, and we did not know if identification was even possible. An experiment was done using both film screen studies and xerograms at various techniques to attempt to locate a honey bee stinger. The stinger could not be identified.

Animals↗