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PubMed1988

Isolation and partial characterization of insulin of the honeybee (Apis mellifica).

In the honeybee (Apis mellifica), insulin-like material was partially purified with acid ethanol extractions by a classic method for recovering insulin and following gel filtration on a Sephadex G-50 column. The preparations were characterized by their ability to cross-react with porcine insulin antibodies. Insulin-like biological activity was demonstrated using the insulin bioassay. Stimulation of glucose oxidation or lipogenesis was measured by isolated rat adipocytes. Insulin seems to be more widespread in invertebrates than was previously assumed.

Adipose Tissue↗

PubMed1971

Analysis of the organization and overlap of the visual fields in the compound eye of the honeybee (Apis mellifera).

Using the results of an optical analysis, a digital computer technique was developed to analyze the relative excitation produced by arbitrary figures at the rhabdom of the receptors of a compound eye. This technique was applied to several sets of figures for the honeybee (Apis mellifera) and a reasonable agreement was found with behavioral data. Similarly, the significance of a fixed cutoff angle for a visual field was investigated. It is concluded that overlap between neighboring ommatidia is highly significant for visual processing in the apposition eye, contrary to the assumptions of the mosaic theory.

Animals↗

PubMed1981

Diffusion and consumption of oxygen in the superfused retina of the drone (Apis mellifera) in darkness.

Double-barreled O2 microelectrodes were used to study O2 diffusion and consumption in the superfused drone (Apis mellifera) retina in darkness at 22 degrees C. Po2 was measured at different sites in the bath and retinas. It was found that diffusion was essentially in one dimension and that the rate of O2 consumption (Q) was practically constant (on the macroscale) down to Po2 s less than 20 mm Hg, a situation that greatly simplified the analysis. The value obtained for Q was 18 +/- 0.7 (SEM) microliter O2/cm3 tissue . min (n = 10), and Krogh's permeation coefficient (alpha D) was 3.24 +/- 0.18 (SEM) X 10(-5) ml O1/min . atm . cm (n = 10). Calculations indicate that only a small fraction of this Q in darkness is necessary for the energy requirements of the sodium pump. the diffusion coefficient (D) in the retina was measured by abruptly cutting off diffusion from the bath and analyzing the time-course of the fall in Po2 at the surface of the tissue. The mean value of D was 1.03 +/- 0.08 (SEM) X 10(-5) cm2/s (n = 10). From alpha D and D, the solubility coefficient alpha was calculated to be 54 +/- 4.0 (SEM) microliter O2 STP/cm3 . atm (n = 10), approximately 1.8 times that for water.

Animals↗

PubMed1993

Characterization of an unusually conserved AluI highly reiterated DNA sequence family from the honeybee, Apis mellifera.

An AluI family of highly reiterated nontranscribed sequences has been found in the genome of the honeybee Apis mellifera. This repeated sequence is shown to be present at approximately 23,000 copies per haploid genome constituting about 2% of the total genomic DNA. The nucleotide sequence of 10 monomers was determined. The consensus sequences is 176 nucleotides long and has an A + T content of 58%. There are clusters of both direct and inverted repeats. Internal subrepeating units ranging from 11 to 17 nucleotides are observed, suggesting that it could have evolved from a shorter sequence. DNA sequence data reveal that this repeat class is unusually homogeneous compared to the other class of invertebrate highly reiterated DNA sequences. The average pairwise sequence divergence between the repeats is 2.5%. In spite of this unusual homogeneity, divergence has been found in the repeated sequence hybridization ladder between four different honeybee subspecies. Therefore, the AluI highly reiterated sequences provide a new probe for fingerprinting in A. m. mellifera.

Animals↗

PubMed1995

Microsatellite variation in honey bee (Apis mellifera L.) populations: hierarchical genetic structure and test of the infinite allele and stepwise mutation models.

Samples from nine populations belonging to three African (intermissa, scutellata and capensis) and four European (mellifera, ligustica, carnica and cecropia) Apis mellifera subspecies were scored for seven microsatellite loci. A large amount of genetic variation (between seven and 30 alleles per locus) was detected. Average heterozygosity and average number of alleles were significantly higher in African than in European subspecies, in agreement with larger effective population sizes in Africa. Microsatellite analyses confirmed that A. mellifera evolved in three distinct and deeply differentiated lineages previously detected by morphological and mitochondrial DNA studies. Dendrogram analysis of workers from a given population indicated that super-sisters cluster together when using a sufficient number of microsatellite data whereas half-sisters do not. An index of classification was derived to summarize the clustering of different taxonomic levels in large phylogenetic trees based on individual genotypes. Finally, individual population x loci data were used to test the adequacy of the two alternative mutation models, the infinite allele model (IAM) and the stepwise mutation models. The better fit overall of the IAM probably results from the majority of the microsatellites used including repeats of two or three different length motifs (compound microsatellites).

Alleles↗

PubMed1972

The P-3 and EST loci in the honeybee Apis mellifera.

Data for Apis mellifera indicate that the P-3 proteins and one esterase enzyme are controlled by two genes, P-3 and Est, with two alleles each. The frequency of the P-3 alleles is different in the two subspecies (adansonii and ligustica), that for P-3(F) in Italian bees being 46.9% and in African 0.5%. The frequency of Est(F) is 2.8% in both populations. The Est locus has two codominant alleles and the locus P-3 has two incompletely dominant alleles; the heterozygote P-3( S)/P-3(F) shows only an intermediate band. The two loci are not genetically linked.

Alleles↗

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↗