Genome-wide analysis of genes related to ovary activation in worker honey bees

Authors

  • G. J. Thompson,

    1. Behaviour and Genetics of Social Insects Laboratory, School of Biological Sciences, University of Sydney, Sydney, NSW, Australia; and
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  • R. Kucharski,

    1. Molecular Genetics & Evolution and ARC Center for the Molecular Genetics of Development, Research School of Biological Sciences, Australian National University, ACT, Australia
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  • R. Maleszka,

    1. Molecular Genetics & Evolution and ARC Center for the Molecular Genetics of Development, Research School of Biological Sciences, Australian National University, ACT, Australia
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    • Authors contributed equally.

  • B. P. Oldroyd

    1. Behaviour and Genetics of Social Insects Laboratory, School of Biological Sciences, University of Sydney, Sydney, NSW, Australia; and
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    • Authors contributed equally.


Graham J Thompson, Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7. Tel.: +1 519 661 2111 ext. 86570; fax: +1 519 661 3935; e-mail: graham.thompson@uwo.ca

Abstract

A defining characteristic of eusocial animals is their division of labour into reproductive and nonreproductive specialists. Here, we used a microarray study to identify genes associated with functional sterility in the worker honey bee Apis mellifera. We contrasted gene expression in workers from a functionally sterile wild-type strain with that in a mutant (anarchist) strain selected for high rates of ovary activation. We identified a small set of genes from the brain (n = 7) and from the abdomen (n = 5) that are correlated in their expression with early stages of ovary activation. Sterile wild-type workers up-regulated two unknown genes and a homologue of Drosophila CG6004. By contrast, reproductive anarchist workers up-regulated genes for the yolk protein vitellogenin, venom peptides and a member of the AdoHycase superfamily, among others. The differentially expressed genes identified are likely to be involved in early differentiation into sterile and reproductive worker phenotypes and may therefore form part of the gene networks associated with the regulation of honey bee worker sterility. Our study may have lacked sufficient power to detect all but a minority of biologically relevant changes taking place; however, the differential expression of vitellogenin and a putative AdoHycase suggests that our screen has captured core reproductive genes and that ovary activation may involve an epigenetic mechanism.

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