Blog
About

20
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Immunogold Localization of Vitellogenin in the Ovaries, Hypopharyngeal Glands and Head Fat Bodies of Honeybee Workers, Apis Mellifera

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Vitellogenin is a yolk precursor protein in most oviparous females. In the advanced eusocial honeybee, Apis mellifera (Hymenoptera: Apidae), vitellogenin has recently attracted much interest as this protein, in addition to a classical function in oocyte development in the reproductive queen caste, has evolved functions in the facultatively sterile female worker caste not documented in other species. However, research on the spatial dynamics of vitellogenin in various tissues is not easily performed with available tools. Here we present an immunogold staining procedure that visualizes honeybee vitellogenin in resin embedded tissue. To establish the protocol, we used ovaries of worker bees from colonies with and without a queen. Under the first condition, vitellogenin is assumed not to be present in the workers' ovaries. Under the second condition, the ovaries of worker bees become vitellogenic, with abundant opportunities for detection of complex patterns of vitellogenin uptake and storage. By use of this experimental setup, the staining method is shown to be both sensitive and specific. To demonstrate the functional significance of the protocol, it was subsequently used to identify vitellogenin protein in the hypopharyngeal glands (brood food producing head glands) of nursing worker bees and in adjacent head fat body cells for the first time. Localization of vitellogenin in these tissues supports previously hypothesized roles of vitellogenin in social behavior. This protocol thus provides deeper insights into the functions of vitellogenin in the honeybee.

          Related collections

          Most cited references 24

          • Record: found
          • Abstract: found
          • Article: not found

          Drosophila dFOXO controls lifespan and regulates insulin signalling in brain and fat body.

          In Drosophila melanogaster, ageing is slowed when insulin-like signalling is reduced: life expectancy is extended by more than 50% when the insulin-like receptor (InR) or its receptor substrate (chico) are mutated, or when insulin-producing cells are ablated. But we have yet to resolve when insulin affects ageing, or whether insulin signals regulate ageing directly or indirectly through secondary hormones. Caenorhabditis elegans lifespan is also extended when insulin signalling is inhibited in certain tissues, or when repressed in adult worms, and this requires the forkhead transcription factor (FOXO) encoded by daf-16 (ref. 6). The D. melanogaster insulin-like receptor mediates phosphorylation of dFOXO, the equivalent of nematode daf-16 and mammalian FOXO3a. We demonstrate here that dFOXO regulates D. melanogaster ageing when activated in the adult pericerebral fat body. We further show that this limited activation of dFOXO reduces expression of the Drosophila insulin-like peptide dilp-2 synthesized in neurons, and represses endogenous insulin-dependent signalling in peripheral fat body. These findings suggest that autonomous and non-autonomous roles of insulin signalling combine to control ageing.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Long-lived Drosophila with overexpressed dFOXO in adult fat body.

            Reduced activity of the insulin/insulin-like growth factor signaling (IIS) pathway increases life-span in diverse organisms. We investigated the timing of the effect of reduced IIS on life-span and the role of a potential target tissue, the fat body. We overexpressed dFOXO, a downstream effector of IIS, in the adult Drosophila fat body, which increased life-span and reduced fecundity of females but had no effect on male life-span. The role of FOXO transcription factors and the adipose tissue are therefore evolutionarily conserved in the regulation of aging, and reduction of IIS in the adult is sufficient to mediate its effects on life-span and fecundity.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Complex social behaviour derived from maternal reproductive traits.

              A fundamental goal of sociobiology is to explain how complex social behaviour evolves, especially in social insects, the exemplars of social living. Although still the subject of much controversy, recent theoretical explanations have focused on the evolutionary origins of worker behaviour (assistance from daughters that remain in the nest and help their mother to reproduce) through expression of maternal care behaviour towards siblings. A key prediction of this evolutionary model is that traits involved in maternal care have been co-opted through heterochronous expression of maternal genes to result in sib-care, the hallmark of highly evolved social life in insects. A coupling of maternal behaviour to reproductive status evolved in solitary insects, and was a ready substrate for the evolution of worker-containing societies. Here we show that division of foraging labour among worker honey bees (Apis mellifera) is linked to the reproductive status of facultatively sterile females. We thereby identify the evolutionary origin of a widely expressed social-insect behavioural syndrome, and provide a direct demonstration of how variation in maternal reproductive traits gives rise to complex social behaviour in non-reproductive helpers.
                Bookmark

                Author and article information

                Affiliations
                [ 1 ]Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, P. O. Box 5003, N–1432 Aas, Norway
                [ 2 ]Department of Plant- and Environmental Sciences, IPM-Microscopy, Norwegian University of Life Sciences, P. O. Box 5003, N-1432 Aas Norway
                [ 3 ]School of Life Sciences, Arizona State University, Tempe, AZ 85287, U.S.A
                Author notes
                Correspondence: [ a ] sirise@ 123456umb.no
                Journal
                J Insect Sci
                insc
                Journal of Insect Science
                University of Wisconsin Library
                1536-2442
                2007
                25 October 2007
                : 7
                2999438
                20337562
                10.1673/031.007.5201
                © 2007

                This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

                Counts
                Pages: 14
                Categories
                Article

                Comments

                Comment on this article