Publications by authors named "Greg J Hunt"

Little is known about the combined effects of stressors on social immunity of honey bees (Apis mellifera) and related gene expression. The interaction between sublethal doses of a neurotoxin, clothianidin, and the ectoparasite, Varroa destructor, was examined by measuring differentially expressed genes (DEGs) in brains, deformed wing virus (DWV) and the proportion and intensity of self-grooming. Evidence for an interaction was observed between the stressors in a reduction in the proportion of intense groomers.

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Honey bee (Apis mellifera) grooming behavior is an important mechanism of resistance against the parasitic mite Varroa destructor. This research was conducted to study associations between grooming behavior and the expression of selected immune, neural, detoxification, developmental and health-related genes. Individual bees tested in a laboratory assay for various levels of grooming behavior in response to V.

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Background: Varroa mites are widely considered the biggest honey bee health problem worldwide. Until recently, Varroa jacobsoni has been found to live and reproduce only in Asian honey bee (Apis cerana) colonies, while V. destructor successfully reproduces in both A.

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Sexual reproduction brings genes from two parents (matrigenes and patrigenes) together into one individual. These genes, despite being unrelated, should show nearly perfect cooperation because each gains equally through the production of offspring. However, an individual's matrigenes and patrigenes can have different probabilities of being present in other relatives, so kin selection could act on them differently.

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Hybrid effects are often exhibited asymmetrically between reciprocal families. One way this could happen is if silencing of one parent's allele occurs in one lineage but not the other, which could affect the phenotypes of the hybrids asymmetrically by silencing that allele in only one of the hybrid families. We have previously tested for allele-specific expression biases in hybrids of European and Africanized honeybees and we found that there was an asymmetric overabundance of genes showing a maternal bias in the family with a European mother.

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Parent-specific gene expression (PSGE) is little known outside of mammals and plants. PSGE occurs when the expression level of a gene depends on whether an allele was inherited from the mother or the father. Kin selection theory predicts that there should be extensive PSGE in social insects because social insect parents can gain inclusive fitness benefits by silencing parental alleles in female offspring.

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Background: Meiotic recombination has traditionally been explained based on the structural requirement to stabilize homologous chromosome pairs to ensure their proper meiotic segregation. Competing hypotheses seek to explain the emerging findings of significant heterogeneity in recombination rates within and between genomes, but intraspecific comparisons of genome-wide recombination patterns are rare. The honey bee (Apis mellifera) exhibits the highest rate of genomic recombination among multicellular animals with about five cross-over events per chromatid.

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The complete mitochondrial genome from an Africanized honey bee population (AHB, derived from Apis mellifera scutellata) was assembled and analyzed. The mitogenome is 16,411 bp long and contains the same gene repertoire and gene order as the European honey bee (13 protein coding genes, 22 tRNA genes and 2 rRNA genes). ND4 appears to use an alternate start codon and the long rRNA gene is 48 bp shorter in AHB due to a deletion in a terminal AT dinucleotide repeat.

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Background: The first generation of genome sequence assemblies and annotations have had a significant impact upon our understanding of the biology of the sequenced species, the phylogenetic relationships among species, the study of populations within and across species, and have informed the biology of humans. As only a few Metazoan genomes are approaching finished quality (human, mouse, fly and worm), there is room for improvement of most genome assemblies. The honey bee (Apis mellifera) genome, published in 2006, was noted for its bimodal GC content distribution that affected the quality of the assembly in some regions and for fewer genes in the initial gene set (OGSv1.

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Varroa mites (V. destructor) are a major threat to honey bees (Apis melilfera) and beekeeping worldwide and likely lead to colony decline if colonies are not treated. Most treatments involve chemical control of the mites; however, Varroa has evolved resistance to many of these miticides, leaving beekeepers with a limited number of alternatives.

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Populations of honey bees in North America have been experiencing high annual colony mortality for 15-20 years. Many apicultural researchers believe that introduced parasites called Varroa mites (V. destructor) are the most important factor in colony deaths.

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A fundamental problem in meta-analysis is how to systematically combine information from multiple statistical tests to rigorously evaluate a single overarching hypothesis. This problem occurs in systems biology when attempting to map genomic attributes to complex phenotypes such as behavior. Behavior and other complex phenotypes are influenced by intrinsic and environmental determinants that act on the transcriptome, but little is known about how these determinants interact at the molecular level.

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In order to identify genes that are influencing defensive behaviors, we have taken a new approach by dissecting colony-level defensive behavior into individual behavioral measurements using two families containing backcross workers from matings involving European and Africanized bees. We removed the social context from stinging behavior by using a laboratory assay to measure the stinging response of individual bees. A mild shock was given to bees using a constant-current stimulator.

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Populations of honey bees and other pollinators have declined worldwide in recent years. A variety of stressors have been implicated as potential causes, including agricultural pesticides. Neonicotinoid insecticides, which are widely used and highly toxic to honey bees, have been found in previous analyses of honey bee pollen and comb material.

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A prominent theory states that animal phenotypes arise by evolutionary changes in gene regulation, but the extent to which this theory holds true for behavioral evolution is not known. Because "nature and nurture" are now understood to involve hereditary and environmental influences on gene expression, we studied whether environmental influences on a behavioral phenotype, i.e.

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Invertebrate models have greatly furthered our understanding of ethanol sensitivity and alcohol addiction. The honey bee (Apis mellifera), a widely used behavioral model, is valuable for comparative studies. A quantitative trait locus (QTL) mapping experiment was designed to identify QTL and genes influencing ethanol vapor sensitivity.

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Several candidate genes identified from quantitative trait loci (QTL) for defensive behavior in honey bees (Apis mellifera L.) are homologous to genes known to influence ethanol sensitivity in other organisms. To investigate this possible link between aggression/defense and ethanol sensitivity, assays were developed to evaluate ethanol vapor responses in worker bees from a low-defensive (gentle) colony and a high-defensive colony.

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This study was conducted to analyze the stinging response thresholds of individual European and Africanized worker honeybees (Apis mellifera L.) to electrical stimulation. Newly emerged workers were identified, and either were placed into an incubator, into their natal colonies, or cross-fostered in common colonies of European or Africanized ancestry.

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The honeybee has been the most important insect species for study of social behavior. The recently released draft genomic sequence for the bee will accelerate honeybee behavioral genetics. Although we lack sufficient tools to manipulate this genome easily, quantitative trait loci (QTLs) that influence natural variation in behavior have been identified and tested for their effects on correlated behavioral traits.

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We have sequenced an 81-kb genomic region from the honey bee, Apis mellifera, associated with a quantitative trait locus (QTL) sting-2 for aggressive behavior. This sequence represents the first extensive study of the honey-bee genome structure encompassing putative genes in a QTL for a behavioral trait. Expression of 13 putative genes, as well as two transcripts that were present in a honey-bee EST database, was confirmed through reverse transcription analysis of mRNA from the honey-bee head.

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One key advantage of eusociality is shared defense of the nest, brood, and stored food; nest defense plays an important role in the biology of eusocial bees. Recent studies on honey bees, Apis mellifera, have focused on the placement of defensive activity in the overall scheme of division of labor, showing that guard bees play a unique and important role in colony defense. Alarm pheromones function in integrating defensive responses; honey bee alarm pheromone is an excellent example of a multicomponent pheromonal blend.

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This study was conducted to test for the effect of three stinging behaviors QTLs (sting-1, sting-2 and sting-3) on the expression of guarding and stinging behavior of individual honey bees, and to determine if results of defensive behavior QTLs found in studies with Africanized honey bees could be extended to other populations of bees. Samples of guards, stingers, foragers and nurse bees were taken from two backcross colonies derived from a defensive colony and a gentle colony. The genotype of each bee for both types of colonies was determined for two sequence tagged site (STS) markers linked to sting-1 and for another two STSs, one linked to sting-2 and one linked to sting-3.

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We analyzed the alarm pheromone components from five colonies of Africanized honeybees and three colonies of European honeybees collected in Mexico. Analyses revealed a novel alarm pheromone component that was only present in appreciable quantities in the Africanized bee samples. Analysis of the mass spectrum and subsequent synthesis confirmed that this compound is 3-methyl-2-buten-1-yl acetate (3M2BA), an unsaturated derivative of IPA.

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The stinging and guarding components of the defensive behavior of European, Africanized, hybrid, and backcross honeybees (Apis mellifera L.) were compared and analyzed at both colony and individual levels. Hybrid and Africanized backcross colonies stung as many times as Africanized ones.

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