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PubMed1977

Estimation of the number of sex alleles and queen matings from diploid male frequencies in a population of Apis mellifera.

The distribution of diploid males in a population of Apis mellifera was obtained by direct examination of the sexual phenotypes of the larvae. Using these data, estimates are derived for the number of sex alleles and the number or matings undergone by the queen. The number of sex alleles is estimated to be 18.9. The estimate is larger than previous ones, which have ranged between 10 and 12. However, the increase in the number of sex alleles can be explained by the large effective population number for our data. The best estimator of the number of matings by a queen is a maximum likelihood type that assumes a prior distribution on the number of matings. For the data presented here, this estimate is 17.3. This estimate is compared to others in the literature obtained by different approaches.

Alleles↗

PubMed1993

Characterization of (GT)n and (CT)n microsatellites in two insect species: Apis mellifera and Bombus terrestris.

A set of 52 (CT)n and 23 (GT)n microsatellites in honeybee, 24 (CT)n and 2 (GT)n microsatellites in bumble-bee (n > 6) have been isolated from partial genomic libraries and sequenced. On average, (CT)n and (GT)n microsatellites occur every 15 kb and 34 kb in honeybee and every 40 kb and 500 kb in bumble-bee, respectively. The prevailing categories are imperfect repeats for (CT)n microsatellites in bumble-bee, and perfect repeats for both (CT)n and (GT)n microsatellites in honey-bee. Comparisons with data available in vertebrates indicate a lower proportion of perfect repeats in bees but length distributions are very similar regardless the phylum. This result extends to insects the concept of an evolutionary conservation for quantitative and qualitative characteristics of (CT)n and (GT)n microsatellites. Many (CT)n and (GT)n repeats are surrounded with various types of microsatellites, revealing an associative distribution of short repeat sequences. As expected, a high level of intrapopulational polymorphism has been found with one tested honeybee microsatellite. Also, flanking regions of this microsatellite are similar enough to allow PCR amplification in several other species of Apis and Bombus.

Animals↗

PubMed1985

Complete amino acid sequence of cytochrome c from the honeybee, Apis mellifera, and evolutionary relationship of the honeybee to other insects on the basis of the amino acid sequence.

The complete amino acid sequence of cytochrome c purified from the honeybee, Apis mellifera was determined. Only one molecular species of cytochrome c was found in the honeybee throughout its metamorphic stages. On the basis of a comparison of the amino acid sequence of honeybee cytochrome c with those of cytochromes c from other insects, it seems that the bee has evolutionarily appeared earlier than would be expected from the morphological and fossil evidence. If the classical phylogenetic relationships of the honeybee are correct, the evolutionary rate of cytochrome c must have been more rapid in the honeybee than in other insects.

Amino Acid Sequence↗

PubMedDate not supplied

Population structure and Mdh-1 locus variation in Apis mellifera ligustica.

In a wide area of the Piedmont of Italy the apiaries of Apis mellifera ligustica Spin., (the Italian bee) show homogeneous allelic frequency distributions at the Mdh-1 locus, the only one known to be polymorphic in worker bees. This can be explained by considering that an apiary is not a closed genetic system and that among apiaries gene flow is sufficient to overcome the different forces of inbreeding and random genetic drift. Nevertheless there is some evidence for partial subdivision because the pooled samples show a weak Wahlund effect. Moreover, the M allele at the same locus can be used as a diagnostic marker to distinguish A. m. ligustica populations (M absent or at very low frequencies) from A. m. mellifera French populations (monomorphic for M). The two honey-bee varieties, almost entirely separated by the Alps, hybridize with each other in very limited alpine areas. Hybrid populations show intermediate M frequencies.

Animals↗

PubMedDate not supplied

Geographical overlap of two mitochondrial genomes in Spanish honeybees (Apis mellifera iberica).

Restriction enzyme cleavage maps of mitochondrial DNA from the Spanish honeybee, Apis mellifera iberica (Hymenoptera: Apidae), were compared with those from the European subspecies A. m. mellifera, A. m. ligustica, and A. m. carnica, and the African subspecies A. m. intermissa and A. m. scutellata. The mitochondrial DNA (mtDNA) of the two African subspecies can be distinguished by restriction fragment polymorphisms revealed by Hinf I digests. Two distinct mtDNA types were found among Spanish honeybees: a west European mellifera-like type, which predominates in the north of Spain, and an African intermissa-like type, which predominates in the south. Spain appears to be a region of contact and hybridization between the two subspecies A. m. intermissa and A. m. mellifera, which respectively represent African and west European honeybee lineages. This natural boundary between European and African honeybee populations in the Old World may provide a model for predicting the eventual outcome of the colonization of North America by introduced African honeybees.

Africa↗

PubMedDate not supplied

Allozyme polymorphisms in Spanish honeybees (Apis mellifera iberica).

Earlier studies have shown two types of mitochondrial DNA in Spanish honeybees (Apis mellifera iberica): a western European or A. m. mellifera type, which predominates in northern Spain, and a north African or A. m. intermissa type, which predominates in southern Spain. Adult workers from 28 colonies sampled in northern and southern Spain were surveyed for polymorphisms at eight allozyme loci. Polymorphisms were found in Mdh1 (two alleles) and Pgm (five alleles). Three of the Pgm alleles have not been described previously. The frequencies of Mdh1 alleles in northern and southern samples are significantly different: Mdh1(80) = 0.94 in the north and 0.75 in the south. The frequencies of Pgm alleles in northern and southern samples do not differ significantly. The Hk allele (Hk100) found in all Spanish samples is the same as that found in other European populations. The results are consistent with the presence of a hybrid zone between African and west European honeybee subspecies in the Iberian peninsula or north Africa. The high number and frequency of novel Pgm alleles in the Spanish bees resembles the "rare allele" phenomenon observed in other hybrid populations.

Animals↗

PubMedDate not supplied

Characterization of honeybee (Apis mellifera L.) chromosomes using repetitive DNA probes and fluorescence in situ hybridization.

Two different repetitive DNA probes of Apis mellifera and ribosomal DNA from Drosophila melanogaster were used to characterize the chromosomal set of the honeybee (n = 16). The probes were hybridized to chromosome preparations of haploid testis tissue from drone larvae using fluorescence in situ hybridization (FISH). The honeybee probes hybridized to the telomeric (Alu I family) and centromeric region (Ava I family) of most chromosomes. The rDNA probe labeled two chromosomes only. Combination of the three probes yielded labeled patterns allowing us to identify each chromosome of the honeybee individually. This is the first report of an unambiguous identification of the chromosomal set of the honeybee, since classical banding techniques failed to yield clear patterns for identification. The consensus sequence of the centromeric reiterated probe (Ava I family) has a length of about 550 nucleotides and shows no homology to other known sequences. However, the structural organization of a 130-nucleotides long motif forming the unusually homogeneous 550 nucleotides repeat is similar to those found in mammals' repetitive DNAs.

Animals↗

PubMed1991

Differential response of Apis mellifera acetylcholinesterase towards pirimicarb.

The kinetic analysis of Apis mellifera acetylcholinesterase inhibition by the carbamate pirimicarb showed that native and detergent-solubilized membrane enzyme exhibited slightly different carbamylation kinetics. The acetylcholinesterase form sensitive to phosphatidylinositol-specific phospholipase C (PI-PLC) was carbamylated more rapidly (kapp = 36.4 X 10(-3) min-1) than the PI-PLC-resistant counterpart (kapp = 10.13 X 10(-3) min-1) which had a behavior close to that of the soluble tryptic enzyme (kapp = 11.89 X 10(-3) min-1). A difference in acetylcholinesterase sensitivity towards pirimicarb was also observed between foraging and emerging bees. These results show that the molecular structure, the mode of preparation and the source of acetylcholinesterase from the bee head should be taken into account in accurate toxicological studies.

Acetylcholinesterase↗

PubMed1977

Biochemical typing of urinary Escherichia coli strains by means of the API 20 E enterobacteriaceae system.

With the API 20 E Enterobacteriaceae system of biochemical testing, a biotype, coded numerically, was determined for each of 574 strains of Escherichia coli isolated from patients with urinary tract infection. The serotypes of the strains were also determined. Fifty-five different biotypes were identified, two accounting together for 42% of the strains examined and seven others each accounting for between 8.4 and 1.9%. There was little correlation between biotype and serotype. Fifty pairs of strains were isolated from patients before treatment. In 43 the biotype and serotype of both strains of each pair were the same. In six pairs the biotype, but not the serotypes, differed, the difference being limited to the results of the tests for lysine decarboxylase. The biotypes of the strains of the remaining pair differed widely although their serotypes were the same. It is suggested that this method of biotyping offers a simple but accurate way of discriminating between recrudescent urinary tract infection caused by E. coli and that due to reinfection.

Bacteriuria↗

PubMed1992

Evolutionary history of the honey bee Apis mellifera inferred from mitochondrial DNA analysis.

Variability of mitochondrial DNA (mtDNA) of the honey bee Apis mellifera L. has been investigated by restriction and sequence analyses on a sample of 68 colonies from ten different subspecies. The 19 mtDNA types detected are clustered in three major phylogenetic lineages. These clades correspond well to three groups of populations with distinct geographical distributions: branch A for African subspecies (intermissa, monticola, scutellata, andansonii and capensis), branch C for North Mediterranean subspecies (caucasica, carnica and ligustica) and branch M for the West European populations (mellifera subspecies). These results partially confirm previous hypotheses based on morphometrical and allozymic studies, the main difference concerning North African populations, now assigned to branch A instead of branch M. The pattern of spatial structuring suggests the Middle East as the centre of dispersion of the species, in accordance with the geographic areas of the other species of the same genus. Based on a conservative 2% divergence rate per Myr, the separation of the three branches has been dated at about 1 Myr BP.

Animals↗

PubMed1984

The purification and characterisation of hyaluronidase from the venom of the honey bee, Apis mellifera.

Hyaluronidase has been purified from the venom of the honey bee, Apis mellifera. The purification proved remarkably difficult, requiring a large number of chromatographic steps culminating in the removal of traces of phospholipase A2 with an affinity purified rabbit anti-phospholipase A2 immunosorbent column. The purified enzyme showed a 1143-fold increase in specific activity and was homogeneous. Electrophoresis in polyacrylamide gels (12%) containing sodium dodecyl sulphate (pH 8.9) or urea (pH 2.8) and electrofocusing in polyacrylamide (5%) gave a single band. The final product contained less than 0.1% phospholipase A2 and less than 1.5% acid phosphatase and gave a single line of precipitation against rabbit anti-hyaluronidase but was not precipitated by rabbit anti-phospholipase A2. Previous reports of instability were not confirmed, and we found the enzyme to be highly stable over a wide range of temperature and pH, and to denaturing agents. Purified hyaluronidase was found to be 'sticky' when highly pure and at low concentration, and adhered strongly to Sephadex G-75. The relative molecular mass was estimated at 35 000-37 000 by gel filtration, and at 41 000 by sodium dodecyl sulphate/polyacrylamide gel electrophoresis. A value of 50 000 was obtained by ultracentrifugation assuming a partial specific volume of 0.73 cm3/g. Hyaluronidase was found to be a minor allergen in bee venom allergic patients.

Amino Acids↗

PubMed1990

Isolation and characterization of abaecin, a major antibacterial response peptide in the honeybee (Apis mellifera).

Honeybee (Apis mellifera) are frequently exposed to and likely to be infected by plant-associated bacteria. We mimicked this process by injecting bees with live bacteria and isolated five induced antibacterial substances by comparative liquid chromatographic mapping of the hemolymph. Three of these antibiotics belong to a unique family of small (18 amino acids) peptides: the apidaecins [Casteels et al. (1989) EMBO J. 8, 2387-2391]. We have now characterized a fourth bee immune response peptide. The complete sequence was established by Edman degradation of the peptide and fragments thereof. It is 34 amino acids long and contains 10 proline residues. The amino-terminal half is related to the apidaecins; similar proline motifs are also present in the amino-terminal quarter of the much longer fly diptericins. The newly identified peptide's broad spectrum, lower specific activities against Gram-negative plant pathogens and its inability to inhibit bacterial growth at medium ionic strength are different from the apidaecins. Moreover, the highest observed specific activity was against an apidaecin-resistant Xanthomonas strain. In contrast to the immediate action of apidaecins, bactericidal activity is delayed. We propose the name 'abaecin' for this new antibacterial response peptide.

Amino Acid Sequence↗

PubMed1991

GDP-fucose: beta-N-acetylglucosamine (Fuc to (Fuc alpha 1----6GlcNAc)-Asn-peptide)alpha 1----3-fucosyltransferase activity in honeybee (Apis mellifica) venom glands. The difucosylation of asparagine-bound N-acetylglucosamine.

Incubation of honeybee (Apis mellifica) venom-gland extracts with GDP-[14C]fucose and GlcNAc beta 1----2Man alpha 1----6(GlcNAc beta 1----2Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4(Fuc alpha 1----6)GlcNAc beta 1----N-Asn-peptide(NAc) gave a labeled product in 40% yield. Analysis by 500-MHz 1H-NMR spectroscopy indicated the transferred fucose-(Fuc) residue to be alpha 1----3-linked to the Asn-bound GlcNAc. Further proof was provided by one-dimensional and two-dimensional 1H-NMR analysis of the incubation mixture, after incubation with beta-N-acetylhexosaminidase. The established carbohydrate structure (formula; see text) proves the existence of a novel alpha 1----3-fucosyltransferase with the ability to effect difucosylation of the Asn-bound GlcNAc in N-glycans.

Acetylglucosamine↗

PubMed1997

Characterisation of the ultraviolet-sensitive opsin gene in the honey bee, Apis mellifera.

The cDNA sequence of the ultraviolet-sensitive opsin in the honey-bee, Apis mellifera, with associated 5' and 3' untranslated regions, is presented. The analysis of genomic structure reveals seven introns in the coding region of the gene, with six at novel positions for an insect opsin gene. The equivalent site to the counterion in vertebrate opsins is occupied by a Tyr residue. This contrasts with the presence of Phe at this site in the ultraviolet-sensitive opsins of Drosophila sps. A comparison of the amino acid sequence within the seven alpha-helical transmembrane regions of insect ultraviolet/blue-sensitive opsins identifies substitution at five sites that involve either replacement of a polar with a non-polar residue, or a change in charge. Such changes are known to result in spectral shifts in vertebrate pigments. Phylogenetic analysis indicates that the ultraviolet-sensitive pigments represent an ancient class of insect opsins.

Amino Acid Sequence↗

PubMed1995

The nitric oxide/cGMP system in the antennal lobe of Apis mellifera is implicated in integrative processing of chemosensory stimuli.

The high concentration and the localization of nitric oxide synthase in the olfactory system of both vertebrates and invertebrates suggest that the diffusible messenger nitric oxide plays a central role in the processing of chemosensory information. This paper describes the nitric oxide releasing system in the antenna and the antennal lobes of Apis mellifera using the NADPH diaphorase technique, and analyses the contribution of the nitric oxide system in the neuronal processing of chemosensory signals using a behavioral assay in vivo. In the antenna the strongest NADPH diaphorase staining is found in non-neuronal auxiliary and/or epithelial cells, while the sensory cells and the antennal nerve are stained at a low level. At the major site of chemosensory signal integration, the antennal lobes, the highest nitric oxide synthase activity is located in the glomeruli, which are ideally suited to act as diffusion compartments. We demonstrate that inhibition of nitric oxide synthase in the antennal lobes specifically interferes with neuronal processing of repetitive chemosensory stimuli but does not affect the response to single stimuli, and is independent of parameters such as satiation level, stimulus strength, interstimulus interval and duration of sensory stimuli. Since inhibition of the soluble guanylate cyclase, a major target of nitric oxide, also particularly affects the adaptive component, the physiological effects of nitric oxide appear to be mediated by the action of cGMP. These findings suggest that the nitric oxide/cGMP system in the antennal lobes is a component of the molecular machinery involved in adaptive and/or integrative mechanisms during chemosensory information processing in vivo.

Animals↗

PubMed1998

Odour coding is bilaterally symmetrical in the antennal lobes of honeybees (Apis mellifera).

The primary olfactory neuropil, the antennal lobe (AL) in insects, is organized in glomeruli. Glomerular activity patterns are believed to represent the across-fibre pattern of the olfactory code. These patterns depend on an organized innervation from the afferent receptor cells, and interconnections of local interneurons. It is unclear how the complex organization of the AL is achieved ontogenetically. In this study, we measured the functional activity patterns elicited by stimulation with odours in the right and the left AL of the same honeybee (Apis mellifera) using optical imaging of the calcium-sensitive dye calcium green. We show here that these patterns are bilaterally symmetrical (n=25 bees). This symmetry holds true for all odours tested, irrespective of their role as pheromones or as environmental odours, or whether they were pure substances or complex blends (n=13 odours). Therefore, we exclude that activity dependent mechanisms local to one AL determine the functional glomerular activity. This identity is genetically predetermined. Alternatively, if activity dependent processes are involved, bilateral connections would have to shape symmetry, or, temporal constraints could lead to identical patterns on both sides due to their common history of odour exposure.

Acyclic Monoterpenes↗

PubMed1983

Modification of potassium movement through the retina of the drone (Apis mellifera male) by glial uptake.

Intracellular recordings were made in photoreceptors and glial cells (outer pigment cells) of the superfused cut head of the honey-bee drone (Apis mellifera male). When the [K+] in the superfusate was abruptly increased from 3.2 mM to 17.9 mM both photoreceptors and glial cells depolarized. The time course of the depolarization of the photoreceptors was slower with increasing depth from the surface. Half time of depolarization was plotted against depth: this graph was compatible with the arrival of K+ being exclusively by diffusion through the extracellular clefts. However, as we then showed, this interpretation is inadequate. The time course of depolarization of the glial cells was almost the same at all depths. This indicates that they are electrically coupled. Consequently, current-mediated K+ flux (spatial buffering) through glial cells will contribute to the transport of K+ through the tissue: K+ ions enter the glial syncytium in the region of high external potassium concentration, [K+]0, and an equivalent quantity of K+ ions leave in regions of low [K+]0. Intracellular K+ activity (aiK) was measured with double-barrelled K+-sensitive micro-electrodes in slices of retina superfused on both faces. When [K+] in the superfusate was increased from 7.5 mM to 17.9 mM an increase in aiK was observed in glial cells at all depths in the slice (initial rate 1.7 mM min-1, S.E. of the mean = 0.2 mM min-1), but there was little increase in the photoreceptors (0.3 +/- 0.2 mM min-1). The increase in aiK in glial cells near the centre of the slice could not have been caused by spatial buffering; it presumably resulted from net uptake. We conclude that when [K+] is increased at the surface of this tissue, the build up of K+ in the extracellular clefts depends on extracellular diffusion, spatial buffering and net uptake. The latter two processes, which have opposing effects, involve about 10 times as much K+ as the first. This is in rough agreement with less direct experiments on mammalian brain (Gardner-Medwin, 1977, 1983b).

Animals↗

PubMed1992

Use of the API rapid NFT system for identifying nonfermentative and fermentative marine bacteria.

Thirty-five American Type Culture Collection type strains of marine bacteria were used to evaluate the Rapid NFT system (API Analab Products, Plainview, N.Y.) for use in identifying heterotrophic marine bacteria. The 21 biochemical and assimilation tests on the Rapid NFT test strips were treated according to the manufacturer's protocol, which included use of AUX medium (provided with the Rapid NFT system) for preparing assimilation tests, and by substituting phenol red broth base (BBL Microbiology Systems, Cockeysville, Md.) with and without an oil overlay for the AUX medium. A seven-digit numerical profile was obtained for each NFT test strip from each of the three procedures and matched to its corresponding number in the Rapid NFT identification codebook. Also, all biochemical and assimilation test results were analyzed with SASTAXAN and SAS/GRAPH programs (SAS Institute, Inc., Cary, N.C.); similarity matrices were computed for all 35 strains. For comparison purposes, bacterial strains were grouped at a similarity level of 70%. The results indicated a low efficacy of identification for all three procedures. In addition, similarity matrix analysis showed more cohesive grouping based on results of phenol red broth base-treated strains than for the AUX medium provided by the manufacturer. However, none of the three treatments provided exclusive grouping of type strains at the genus level. Thus, the reliability of the data obtained from the NFT system and modifications thereof should be evaluated carefully when environmental isolates are characterized.

Bacteria↗