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Eamonn B Mallon - One of the best experts on this subject based on the ideXlab platform.

  • Allele specific expression and methylation in the bumblebee, Bombus terrestris
    PeerJ, 2017
    Co-Authors: Zoë N. Lonsdale, Harindra E Amarasinghe, Despina Nathanael, Kate Lee, Maria Kyriakidou, Catherine J. O’connor, Eamonn B Mallon
    Abstract:

    The social hymenoptera are emerging as models for epigenetics. DNA methylation, the addition of a methyl group, is a common epigenetic marker. In mammals and flowering plants methylation affects allele specific expression. There is contradictory evidence for the role of methylation on allele specific expression in social insects. The aim of this paper is to investigate allele specific expression and monoallelic methylation in the bumblebee, Bombus terrestris. We found nineteen genes that were both monoallelically methylated and monoallelically expressed in a single bee. Fourteen of these genes express the hypermethylated allele, while the other five express the hypomethylated allele. We also searched for allele specific expression in twenty-nine published RNA-seq libraries. We found 555 loci with allele-specific expression. We discuss our results with reference to the functional role of methylation in gene expression in insects and in the as yet unquantified role of genetic cis effects in insect allele specific methylation and expression.

  • Allele specific expression in worker reproduction genes in the bumblebee Bombus terrestris
    2015
    Co-Authors: Harindra E Amarasinghe, Bradley J Toghill, Despina Nathanael, Eamonn B Mallon
    Abstract:

    Methylation has previously been associated with allele specific expression in ants. Recently, we found methylation is important in worker reproduction in the bumblebee Bombus terrestris. Here we searched for allele specific expression in twelve genes associated with worker reproduction in bees. We found allele specific expression in Ecdysone 20 monooxygenase and IMP-L2-like. Although we were unable to confirm a genetic or epigenetic cause for this allele specific expression, the expression patterns of the two genes match those predicted for imprinted genes.

  • Allele specific expression in worker reproduction genes in the bumblebee Bombus terrestris
    2015
    Co-Authors: Harindra E Amarasinghe, Bradley J Toghill, Eamonn B Mallon
    Abstract:

    Genomic imprinting is the differential expression of alleles, with the expression being dependent upon the sex of the parent from which it was inherited. Hymenopteran insects (ants, bees and wasps) are emerging as potential models for genomic imprinting and epigenetics. As a first step in establishing the possibility of genomic imprinting in the bumblebee, Bombus terrestris, we search for allele specific expression in twelve genes associated with worker reproduction. We found that the patrigene (allele from the father) is more expressed than the matrigene (allele from the mother) in Ecdysone 20 monooxygenase. This enzyme catalyses the reaction which turns the ecdysteroid ecdysone into 20-hydroxyecdysone, also an ecdysteroid. Both of these ecdysteroids are important for worker reproduction in the bumblebee.

  • Methylation and worker reproduction in the bumble-bee (Bombus terrestris)
    Proceedings of The Royal Society B: Biological Sciences, 2014
    Co-Authors: Harindra E Amarasinghe, Crisenthiya I. Clayton, Eamonn B Mallon
    Abstract:

    Insects are at the dawn of an epigenetics era. Numerous social insect species have been found to possess a functioning methylation system, previously not thought to exist in insects. Methylation, an epigenetic tag, may be vital for the sociality and division of labour for which social insects are renowned. In the bumble-bee Bombus terrestris, we found methylation differences between the genomes of queenless reproductive workers and queenless non-reproductive workers. In a follow up experiment, queenless workers whose genomes had experimentally altered methylation were more aggressive and more likely to develop ovaries compared with control queenless workers. This shows methylation is important in this highly plastic reproductive division of labour. Methylation is an epigenetic tag for genomic imprinting (GI). It is intriguing that the main theory to explain the evolution of GI predicts that GI should be important in this worker reproduction behaviour.

  • Behavioural interactions, kin and disease susceptibility in the bumblebee Bombus terrestris.
    Journal of Evolutionary Biology, 2004
    Co-Authors: Eamonn B Mallon, Paul Schmid-hempel
    Abstract:

    Behavioural interactions are often analysed in terms of their costs and benefits to the actors [Hamilton, (1964) J. Theor. Biol. 7 1–16; Gadagkar, (1993) Trends Ecol. Evol. 8 232–234; Foster et al., (2001) Ann. Zool. Fenn. 38 229–238]. Using the bumblebee Bombus terrestris, we wish to distinguish between two possible determinants of interaction behaviour between conspecifics, namely kindirected behaviour that reflects genetic distance between individuals, or, alternatively, interactions guided by a functional distance between individuals, specifically, with respect to disease susceptibility. We find no relationship between contact rate of individuals and the genetic distance of their respective colonies. Interestingly, we do find a significant negative correlation between contact rate and the distance between the two colonies in susceptibility to a spectrum of parasite strains. This cannot be explained by either of the a priori alternatives so we propose two further testable hypotheses to explain our results.

Paul Schmidhempel - One of the best experts on this subject based on the ideXlab platform.

  • foraging activity and immunocompetence in workers of the bumble bee Bombus terrestris l
    Proceedings of The Royal Society B: Biological Sciences, 1995
    Co-Authors: Cornelia Konig, Paul Schmidhempel
    Abstract:

    A fundamental assumption of coevolutionary models of host-parasite relations is that resistance is costly. Costs are envisioned as phenotypic or genetic trade-offs in the allocation of limited resources to specific tasks. Using workers of the bumble bee Bombus terrestris L., we tested experimentally whether foraging effort, an energetically costly and crucially important task that ensures colony growth, survival and reproduction, is costly in terms of reduced resistance against parasite attack. The experiment showed that indeed workers allowed to forage showed lower levels of immunocompetence, as measured by the degree of encapsulation of a novel antigen, than workers prevented from foraging activity.

Js Birnbaum - One of the best experts on this subject based on the ideXlab platform.

Wittko Francke - One of the best experts on this subject based on the ideXlab platform.

Cornelia Konig - One of the best experts on this subject based on the ideXlab platform.

  • foraging activity and immunocompetence in workers of the bumble bee Bombus terrestris l
    Proceedings of The Royal Society B: Biological Sciences, 1995
    Co-Authors: Cornelia Konig, Paul Schmidhempel
    Abstract:

    A fundamental assumption of coevolutionary models of host-parasite relations is that resistance is costly. Costs are envisioned as phenotypic or genetic trade-offs in the allocation of limited resources to specific tasks. Using workers of the bumble bee Bombus terrestris L., we tested experimentally whether foraging effort, an energetically costly and crucially important task that ensures colony growth, survival and reproduction, is costly in terms of reduced resistance against parasite attack. The experiment showed that indeed workers allowed to forage showed lower levels of immunocompetence, as measured by the degree of encapsulation of a novel antigen, than workers prevented from foraging activity.