1
|
Kratz M, Manning R, Dods K, Baer B, Blache D. Nurse bees regulate the larval nutrition of developing workers (Apis mellifera) when feeding on various pollen types. J Econ Entomol 2024:toae045. [PMID: 38606526 DOI: 10.1093/jee/toae045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/28/2024] [Accepted: 02/28/2024] [Indexed: 04/13/2024]
Abstract
Nutrition has been identified as a key driver of colony health and productivity. Yet, in honey bees, relatively little is known about how the vast variety of natural pollen sources impact larval development. The impact of the nutritional quality of 4 naturally occurring pollen sources, of importance to the Western Australian beekeeping industry, was tested on honey bee (Apis mellifera L.) development. Bee packages consisting of 800 g of bees and a mated sister queen were assigned to 40 nucleus hives and randomly allocated to one of the 4 feed treatments (10 colonies each) of marri (Corymbia calophylla Lindl.), jarrah (Eucalyptus marginata Sm.), clover (Trifolium repens L.), and canola (Brassica napus L.) pollen. Emerging bees were collected once the first bees started hatching on the assigned feed sources. Newly emerging bees were weighed individually, and body composition was measured in batches according to the feed treatment groups. Food consumption was recorded for the duration of the experiment. Nurse bees successfully raised young adult workers from the larval stage until emergence when fed with one of 4 pollen patties with different nutritional qualities. There was no difference in the body composition or weight of emerging bees fed on the different pollen types. However, the body weight of bees increased over time, most likely related to colony size and structure. With the type of pollen patties having little impact on larval development, the availability of pollen may be more important than its composition, providing bees have access to all essential nutrients.
Collapse
Affiliation(s)
- Madlen Kratz
- School of Molecular Sciences, The University of Western Australia, Bayliss Building (M316), Crawley, WA 6009, Australia
- School of Agriculture and Environment (M087), University of Western Australia Institute of Agriculture, The University of Western Australia, Crawley, WA 6009, Australia
- New South Wales Department of Primary Industries, 815 Tocal Road, Paterson, NSW 2421, Australia
| | - Robert Manning
- Formerly, Plant Biosecurity, Western Australian Department of Agriculture and Food, South Perth, WA 6151, Australia
- RMO Consultancy, 301 Forrest Road, Bibra lake, WA, Australia
| | - Kenneth Dods
- Formerly, ChemCentre, Resources and Chemistry Precinct, Bentley, WA, Australia
- SAGE Consultancy, Perth, WA, Australia
| | - Boris Baer
- Center for Integrative Bee Research (CIBER), Department of Entomology, The University of California, Riverside, CA 92506, USA
| | - Dominique Blache
- School of Agriculture and Environment (M087), University of Western Australia Institute of Agriculture, The University of Western Australia, Crawley, WA 6009, Australia
| |
Collapse
|
2
|
Baer-Imhoof B, den Boer SPA, Boomsma JJ, Baer B. Sperm Storage Costs Determine Survival and Immunocompetence in Newly Mated Queens of the Leaf-Cutting Ant Atta colombica. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.759183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In the leaf-cutting ant Atta colombica, queens receive ejaculates from multiple males during one single mating event early in their lives. A queen’s fertility and fitness therefore depend on maximizing the number of sperm cells she can store and maintain inside her spermatheca. Previous studies implied significant physiological mating costs, either originating from energetic investments maximizing sperm survival, or from resolving sexual conflicts to terminate male-driven incapacitation of rival sperm via serine proteases found in seminal fluid. Here we conducted an artificial insemination experiment, which allowed us to distinguish between the effects of sperm and seminal fluid within the queen’s sexual tract on her survival and immunocompetence. We found significantly higher mortality in queens that we had inseminated with sperm, independently of whether seminal fluid was present or not. Additionally, after receiving sperm, heavier queens had a higher probability of survival compared to lightweight queens, and immunocompetence decreased disproportionally for queens that had lost weight during the experiment. These findings indicate that queens pay significant physiological costs for maintaining and storing sperm shortly after mating. On the other hand, the presence of seminal fluid within the queens’ sexual tract neither affected their survival nor their immunocompetence. This suggests that the energetic costs that queens incur shortly after mating are primarily due to investments in sperm maintenance and not costs of terminating conflicts between competing ejaculates. This outcome is consistent with the idea that sexually selected traits in social insects with permanent castes can evolve only when they do not affect survival or life-time fitness of queens in any significant way.
Collapse
|
3
|
Holt S, Cremen N, Grassl J, Schmid-Hempel P, Baer B. Genetic Variation in Antimicrobial Activity of Honey Bee (Apis mellifera) Seminal Fluid. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.755226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Honey bees can host a remarkably large number of different parasites and pathogens, and some are known drivers of recent declines in wild and managed bee populations. Here, we studied the interactions between the fungal pathogen Nosema apis and seminal fluid of the Western honey bee (Apis mellifera). Honey bee seminal fluid contains multiple antimicrobial molecules that kill N. apis spores and we therefore hypothesized that antimicrobial activities of seminal fluid are genetically driven by interactions between honey bee genotype and different N. apis strains/ecotypes, with the virulence of a strain depending on the genotype of their honey bee hosts. Among the antimicrobials, chitinases have been found in honey bee seminal fluid and have the predicted N. apis killing capabilities. We measured chitinase activity in the seminal fluid of eight different colonies. Our results indicate that multiple chitinases are present in seminal fluid, with activity significantly differing between genotypes. We therefore pooled equal numbers of N. apis spores from eight different colonies and exposed subsamples to seminal fluid samples from each of the colonies. We infected males from each colony with seminal fluid exposed spore samples and quantified N. apis infections after 6 days. We found that host colony had a stronger effect compared to seminal fluid treatment, and significantly affected host mortality, infection intensity and parasite prevalence. We also found a significant effect of treatment, as well as a treatment × colony interaction when our data were analyzed ignoring cage as a blocking factor. Our findings provide evidence that N. apis-honey bee interactions are driven by genotypic effects, which could be used in the future for breeding purposes of disease resistant or tolerant honey bee stock.
Collapse
|
4
|
Duffy C, Sorolla A, Wang E, Golden E, Woodward E, Davern K, Ho D, Johnstone E, Pfleger K, Redfern A, Iyer KS, Baer B, Blancafort P. Honeybee venom and melittin suppress growth factor receptor activation in HER2-enriched and triple-negative breast cancer. NPJ Precis Oncol 2020; 4:24. [PMID: 32923684 PMCID: PMC7463160 DOI: 10.1038/s41698-020-00129-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 07/28/2020] [Indexed: 12/13/2022] Open
Abstract
Despite decades of study, the molecular mechanisms and selectivity of the biomolecular components of honeybee (Apis mellifera) venom as anticancer agents remain largely unknown. Here, we demonstrate that honeybee venom and its major component melittin potently induce cell death, particularly in the aggressive triple-negative and HER2-enriched breast cancer subtypes. Honeybee venom and melittin suppress the activation of EGFR and HER2 by interfering with the phosphorylation of these receptors in the plasma membrane of breast carcinoma cells. Mutational studies reveal that a positively charged C-terminal melittin sequence mediates plasma membrane interaction and anticancer activity. Engineering of an RGD motif further enhances targeting of melittin to malignant cells with minimal toxicity to normal cells. Lastly, administration of melittin enhances the effect of docetaxel in suppressing breast tumor growth in an allograft model. Our work unveils a molecular mechanism underpinning the anticancer selectivity of melittin, and outlines treatment strategies to target aggressive breast cancers.
Collapse
Affiliation(s)
- Ciara Duffy
- School of Human Sciences, The University of Western Australia, Perth, WA 6009 Australia.,Cancer Epigenetics Group, Harry Perkins Institute of Medical Research, Perth, WA 6009 Australia.,Plant Energy Biology, The University of Western Australia, Perth, WA 6009 Australia.,Centre for Medical Research, The University of Western Australia, Perth, WA 6009 Australia
| | - Anabel Sorolla
- Cancer Epigenetics Group, Harry Perkins Institute of Medical Research, Perth, WA 6009 Australia.,Centre for Medical Research, The University of Western Australia, Perth, WA 6009 Australia
| | - Edina Wang
- Cancer Epigenetics Group, Harry Perkins Institute of Medical Research, Perth, WA 6009 Australia.,Centre for Medical Research, The University of Western Australia, Perth, WA 6009 Australia
| | - Emily Golden
- Cancer Epigenetics Group, Harry Perkins Institute of Medical Research, Perth, WA 6009 Australia.,Centre for Medical Research, The University of Western Australia, Perth, WA 6009 Australia
| | - Eleanor Woodward
- Cancer Epigenetics Group, Harry Perkins Institute of Medical Research, Perth, WA 6009 Australia.,Centre for Medical Research, The University of Western Australia, Perth, WA 6009 Australia
| | - Kathleen Davern
- Centre for Medical Research, The University of Western Australia, Perth, WA 6009 Australia.,Monoclonal Antibody (MAb) Facility, Harry Perkins Institute of Medical Research, Perth, WA 6009 Australia
| | - Diwei Ho
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009 Australia
| | - Elizabeth Johnstone
- Centre for Medical Research, The University of Western Australia, Perth, WA 6009 Australia.,Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, Perth, WA 6009 Australia.,Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, Australia
| | - Kevin Pfleger
- Centre for Medical Research, The University of Western Australia, Perth, WA 6009 Australia.,Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, Perth, WA 6009 Australia.,Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, Australia.,Dimerix Limited; Nedlands, Perth, WA 6009 Australia
| | - Andrew Redfern
- School of Medicine, The University of Western Australia, Perth, WA 6009 Australia
| | - K Swaminathan Iyer
- Monoclonal Antibody (MAb) Facility, Harry Perkins Institute of Medical Research, Perth, WA 6009 Australia
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), Department of Entomology; University of California Riverside, Riverside, CA 92521 USA
| | - Pilar Blancafort
- School of Human Sciences, The University of Western Australia, Perth, WA 6009 Australia.,Cancer Epigenetics Group, Harry Perkins Institute of Medical Research, Perth, WA 6009 Australia.,Centre for Medical Research, The University of Western Australia, Perth, WA 6009 Australia.,The Greehey Children's Cancer Research Institute, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229 USA
| |
Collapse
|
5
|
Al Naggar Y, Baer B. Consequences of a short time exposure to a sublethal dose of Flupyradifurone (Sivanto) pesticide early in life on survival and immunity in the honeybee (Apis mellifera). Sci Rep 2019; 9:19753. [PMID: 31874994 PMCID: PMC6930273 DOI: 10.1038/s41598-019-56224-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 12/04/2019] [Indexed: 12/26/2022] Open
Abstract
Dramatic losses of pollinating insects have become of global concern, as they threaten not only key ecosystem services but also human food production. Recent research provided evidence that interactions between ecological stressors are drivers of declining pollinator health and responsible for observed population collapses. We used the honeybee Apis mellifera and conducted a series of experiments to test for long-term effects of a single short exposure to the agricultural pesticide flupyradifurone to a second environmental stressor later in life. To do this, we exposed individuals during their larval development or early adulthood to sublethal dosages of flupyradifurone (0.025 μg for larvae and 0.645 μg for imagos), either pure or as part of an agricultural formulation (Sivanto). We afterwards exposed bees to a second ecological stressor infecting individuals with 10,000 spores of the fungal gut parasite Nosema ceranae. We found that pesticide exposures significantly reduced survival of bees and altered the expression of several immune and detoxification genes. The ability of bees to respond to these latter effects differed significantly between colonies, offering opportunities to breed bees with elevated levels of pesticide tolerance in the future. We conclude that short episodes of sublethal pesticide exposures during development are sufficient to trigger effects later in life and could therefore contribute to the widespread declines in bee health.
Collapse
Affiliation(s)
- Yahya Al Naggar
- Center for Integrative Bee Research (CIBER), Department of Entomology, University of California Riverside, Riverside, CA, 92507, USA. .,Zoology Department, Faculty of Science, Tanta University31527, Tanta, Egypt. .,General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher weg 8, 06120, Halle (Saale), Germany.
| | - Boris Baer
- Center for Integrative Bee Research (CIBER), Department of Entomology, University of California Riverside, Riverside, CA, 92507, USA.
| |
Collapse
|
6
|
Liberti J, Görner J, Welch M, Dosselli R, Schiøtt M, Ogawa Y, Castleden I, Hemmi JM, Baer-Imhoof B, Boomsma JJ, Baer B. Seminal fluid compromises visual perception in honeybee queens reducing their survival during additional mating flights. eLife 2019; 8:45009. [PMID: 31500699 PMCID: PMC6739865 DOI: 10.7554/elife.45009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 08/05/2019] [Indexed: 12/18/2022] Open
Abstract
Queens of social insects make all mate-choice decisions on a single day, except in honeybees whose queens can conduct mating flights for several days even when already inseminated by a number of drones. Honeybees therefore appear to have a unique, evolutionarily derived form of sexual conflict: a queen’s decision to pursue risky additional mating flights is driven by later-life fitness gains from genetically more diverse worker-offspring but reduces paternity shares of the drones she already mated with. We used artificial insemination, RNA-sequencing and electroretinography to show that seminal fluid induces a decline in queen vision by perturbing the phototransduction pathway within 24–48 hr. Follow up field trials revealed that queens receiving seminal fluid flew two days earlier than sister queens inseminated with saline, and failed more often to return. These findings are consistent with seminal fluid components manipulating queen eyesight to reduce queen promiscuity across mating flights. For social insects like honeybees it is beneficial if their queens mate with many males, because genetic diversity can protect the hive against parasites. Early in life, a honeybee queen has a short period of time in which she can fly out to mate with males before returning to the hive with all the sperm needed to last for a lifetime. Queens that have mated on their first flight may embark on additional mating flights over a few consecutive days to further increase genetic variability in their offspring. This is problematic for a male that has already mated because the more males that inseminate the queen the fewer offspring will carry on his specific genes. This results in sexual conflict between males and queens over the number of mating flights. In many animals, males manipulate females using molecules in seminal fluid to reduce the chances of the female mating again and honeybee males may use a similar strategy. Previous studies revealed that insemination alters the activity of genes related to vision in a honeybee queen’s brain. This could be one way for the males to prevent queens from embarking on additional mating flights. Now, Liberti et al. find support for this idea by showing that seminal fluid can indeed trigger changes in the activity of vision-related genes in the brains of honeybee queens, which in turn reduce a queen’s opportunity to complete additional mating flights. Queens inseminated with seminal fluid were less responsive to light compared to queens that were exposed to saline instead. Electronic tracking devices affixed to queens showed that the seminal fluid-exposed queens left for mating flights sooner but were more likely to get lost and to not return to their hives compared to the saline-exposed queens. The experiments support the idea of a sexual arms race in honeybees. Males use seminal fluid to cause rapid deteriorating vision in queens, thus reducing their likelihood of leaving the hive to mate again and to find males when they do fly again. The queens try to counteract these effects by leaving for mating flights sooner, thereby increasing offspring genetic diversity and the success of their colonies. Further studies will be needed to find out how the honeybee sexual arms race varies across seasons, bee races, and geographic ranges. Such information will be useful for honeybee breeding programs, which rely on queen mating success and hive genetic diversity to ensure hive health.
Collapse
Affiliation(s)
- Joanito Liberti
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Julia Görner
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Australia
| | - Mat Welch
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Australia
| | - Ryan Dosselli
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Australia.,Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, Crawley, Australia
| | - Morten Schiøtt
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Yuri Ogawa
- School of Animal Biology and UWA Oceans Institute, The University of Western Australia, Crawley, Australia
| | - Ian Castleden
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Australia
| | - Jan M Hemmi
- School of Animal Biology and UWA Oceans Institute, The University of Western Australia, Crawley, Australia
| | - Barbara Baer-Imhoof
- Centre for Integrative Bee Research (CIBER), Department of Entomology, University of California, Riverside, Riverside, United States
| | - Jacobus J Boomsma
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), Department of Entomology, University of California, Riverside, Riverside, United States
| |
Collapse
|
7
|
Dosselli R, Grassl J, den Boer SPA, Kratz M, Moran JM, Boomsma JJ, Baer B. Protein-Level Interactions as Mediators of Sexual Conflict in Ants. Mol Cell Proteomics 2019; 18:S34-S45. [PMID: 30598476 PMCID: PMC6427229 DOI: 10.1074/mcp.ra118.000941] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 12/06/2018] [Indexed: 12/11/2022] Open
Abstract
All social insects with obligate reproductive division of labor evolved from strictly monogamous ancestors, but multiple queen-mating (polyandry) arose de novo, in several evolutionarily derived lineages. Polyandrous ant queens are inseminated soon after hatching and store sperm mixtures for a potential reproductive life of decades. However, they cannot re-mate later in life and are thus expected to control the loss of viable sperm because their lifetime reproductive success is ultimately sperm limited. In the leaf-cutting ant Atta colombica,, the survival of newly inseminated sperm is known to be compromised by seminal fluid of rival males and to be protected by secretions of the queen sperm storage organ (spermatheca). Here we investigate the main protein-level interactions that appear to mediate sperm competition dynamics and sperm preservation. We conducted an artificial insemination experiment and DIGE-based proteomics to identify proteomic changes when seminal fluid is exposed to spermathecal fluid followed by a mass spectrometry analysis of both secretions that allowed us to identify the sex-specific origins of the proteins that had changed in abundance. We found that spermathecal fluid targets only seven (2%) of the identified seminal fluid proteins for degradation, including two proteolytic serine proteases, a SERPIN inhibitor, and a semen-liquefying acid phosphatase. In vitro, and in vivo, experiments provided further confirmation that these proteins are key molecules mediating sexual conflict over sperm competition and viability preservation during sperm storage. In vitro, exposure to spermathecal fluid reduced the capacity of seminal fluid to compromise survival of rival sperm in a matter of hours and biochemical inhibition of these seminal fluid proteins largely eliminated that adverse effect. Our findings indicate that A. colombica, queens are in control of sperm competition and sperm storage, a capacity that has not been documented in other animals but is predicted to have independently evolved in other polyandrous social insects.
Collapse
Affiliation(s)
- Ryan Dosselli
- From the ‡ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, Bayliss Building (M316),; Centre for Evolutionary Biology, School of Biological Sciences (M092),; Honey Bee Health Research Group, School of Molecular Sciences (M316), The University of Western Australia, Crawley WA 6009, Australia
| | - Julia Grassl
- From the ‡ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, Bayliss Building (M316),; Honey Bee Health Research Group, School of Molecular Sciences (M316), The University of Western Australia, Crawley WA 6009, Australia
| | - Susanne P A den Boer
- From the ‡ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, Bayliss Building (M316),; Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Madlen Kratz
- From the ‡ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, Bayliss Building (M316),; Honey Bee Health Research Group, School of Molecular Sciences (M316), The University of Western Australia, Crawley WA 6009, Australia
| | - Jessica M Moran
- From the ‡ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, Bayliss Building (M316),; Centre for Evolutionary Biology, School of Biological Sciences (M092),; Honey Bee Health Research Group, School of Molecular Sciences (M316), The University of Western Australia, Crawley WA 6009, Australia
| | - Jacobus J Boomsma
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark;.
| | - Boris Baer
- Center for Integrative Bee Research (CIBER), Department of Entomology, The University of California, Riverside CA 92506.
| |
Collapse
|
8
|
Grassl J, Holt S, Cremen N, Peso M, Hahne D, Baer B. Synergistic effects of pathogen and pesticide exposure on honey bee (Apis mellifera) survival and immunity. J Invertebr Pathol 2018; 159:78-86. [DOI: 10.1016/j.jip.2018.10.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 10/01/2018] [Accepted: 10/05/2018] [Indexed: 01/20/2023]
|
9
|
Shaw JA, Boyd A, House M, Cowin G, Baer B. Multi-modal imaging and analysis in the search for iron-based magnetoreceptors in the honeybee Apis mellifera. R Soc Open Sci 2018; 5:181163. [PMID: 30839746 PMCID: PMC6170574 DOI: 10.1098/rsos.181163] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 08/09/2018] [Indexed: 06/09/2023]
Abstract
The honeybee Apis mellifera is one of many animal species for which empirical evidence of a magnetic sense has been provided. The underlying mechanisms postulated for magnetoreception in bees are varied, but most point towards the abdomen as the most likely anatomical region for its location, partly owing to the large accumulation of iron in trophocyte cells that comprise the honeybee fat body. Using a multi-modal imaging and analysis approach, we have investigated iron in the honeybee, with a particular focus on the abdomen and the utility of such techniques as applied to magnetoreception. Abdominal iron is shown to accumulate rapidly, reaching near maximum levels only 5 days after emerging from the comb and is associated with the accumulation of iron within the fat body. While fat body iron could be visualized, no regions of interest, other than perhaps the fat body itself, were identified as potential sites for magnetoreceptive cells. If an iron-based magnetoreceptor exists within the honeybee abdomen the large accumulation of iron in the fat body is likely to impede its discovery.
Collapse
Affiliation(s)
- Jeremy A. Shaw
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Alastair Boyd
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Michael House
- School of Physics, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Gary Cowin
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Boris Baer
- Centre for Integrative Bee Research, Department of Entomology, University of California, Riverside, CA 92521, USA
| |
Collapse
|
10
|
Abstract
Background Promiscuous mating and sperm competition often induce arms races between the sexes with detrimental outcomes for females. However, ants with multiply-inseminated queens have only a single time-window for sperm competition and queens are predicted to gain control over the outcome of sperm storage quickly. The seminal fluid of Acromyrmex leaf-cutting ants reduces the viability of rival sperm, but how confrontations between unrelated ejaculates affect sperm storage remains unknown. Results We investigated the effects of ejaculate admixture on sperm motility in A. echinatior and found that the proportion of motile spermatozoa, sperm swimming speed, and linearity of sperm movement increased when rival ejaculates were mixed in vitro. Major effects induced by the seminal fluid of rival males were of similar magnitude to those generated by queen reproductive tract secretions, whereas own seminal fluid induced lower sperm activation levels. Conclusions Our results suggest that ant sperm respond via a self–non-self recognition mechanism to similar or shared molecules expressed in the reproductive secretions of both sexes. Lower sperm motility in the presence of own seminal fluid indicates that enhanced motility is costly and may trade-off with sperm viability during sperm storage, consistent with studies in vertebrates. Our results imply that ant spermatozoa have evolved to adjust their energetic expenditure during insemination depending on the perceived level of sperm competition. Electronic supplementary material The online version of this article (10.1186/s12862-018-1144-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Joanito Liberti
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark.
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), Department of Entomology, University of California Riverside, Riverside, CA, 92521, USA
| | - Jacobus J Boomsma
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark.
| |
Collapse
|
11
|
Chérasse S, Baer B, Schiøtt M, Boomsma JJ. Differential immune gene expression in sperm storage organs of leaf-cutting ants. ACTA ACUST UNITED AC 2018; 221:jeb.173435. [PMID: 29444846 DOI: 10.1242/jeb.173435] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 02/01/2018] [Indexed: 02/04/2023]
Abstract
Leaf-cutting ant queens mate with multiple males during a single nuptial flight and store sperm for up to two decades. During mating, males transfer sperm from their accessory testes to the queen bursa copulatrix from where it enters the spermatheca, an insect sperm storage organ that has become highly specialized in long-lived ant queens who never re-mate later in life. Long-term storage without the possibility to obtain new sperm creates an immune defence dilemma, because recognition of non-self cells eliminates infections but may also target irreplaceable sperm and reduce lifetime reproductive success. We therefore hypothesized that non-specific immune responses, like pathogen melanization, should be silenced in the spermatheca, because they rely on general non-self recognition, and that specific responses such as antimicrobial peptides are activated instead as they specifically target pathogenic bacteria and/or fungi. The maintenance of uninfected sperm cells by males before mating is not constrained by non-self recognition, meaning immune regulation might be more liberal in male reproductive organs. To test this hypothesis, we measured gene expression of two antimicrobial peptides, abaecin and defensin, and prophenoloxidase, an important enzyme of the melanization pathway, in male accessory glands and testes and in queen bursae copulatrix and spermathecae of Acromyrmex echinatior and Atta colombica leaf-cutting ants. As expected, prophenoloxidase expression was low in reproductive organs that sustain prolonged contact with sperm, whereas antimicrobial peptides showed average to high expression, indicating that leaf-cutting ants invest in specific rather than generalist immune defences for pathogen protection in organs that store sperm.
Collapse
Affiliation(s)
- Sarah Chérasse
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark .,Evolutionary Biology and Ecology, Department of Organism Biology, Université Libre de Bruxelles, Av. F.D. Roosevelt 50, CP 160/12, B-1050 Brussels, Belgium
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), Department of Entomology, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, USA
| | - Morten Schiøtt
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Jacobus J Boomsma
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| |
Collapse
|
12
|
Abstract
Queens of Acromyrmex leaf-cutting ants store sperm of multiple males after a single mating flight, and never remate even though they may live for decades and lay tens of thousands of eggs. Sperm of different males are initially transferred to the bursa copulatrix and compete for access to the long-term storage organ of queens, but the factors determining storage success or failure have never been studied. We used in vitro experiments to show that reproductive tract secretions of Acromyrmex echinatior queens increase sperm swimming performance by at least 50% without discriminating between sperm of brothers and unrelated males. Indiscriminate female-induced sperm chemokinesis makes the likelihood of storage directly dependent on initial sperm viability and thus provides a simple mechanism to secure maximal possible reproductive success of queens, provided that initial sperm motility is an accurate predictor of viability during later egg fertilization.
Collapse
Affiliation(s)
- Joanito Liberti
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), The University of Western Australia, Bayliss Building M316, Crawley, Western Australia 6009, Australia
| | - Jacobus J Boomsma
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
| |
Collapse
|
13
|
Paynter E, Millar AH, Welch M, Baer-Imhoof B, Cao D, Baer B. Insights into the molecular basis of long-term storage and survival of sperm in the honeybee (Apis mellifera). Sci Rep 2017; 7:40236. [PMID: 28091518 PMCID: PMC5238380 DOI: 10.1038/srep40236] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 12/02/2016] [Indexed: 11/12/2022] Open
Abstract
Honeybee males produce ejaculates consisting of large numbers of high quality sperm. Because queens never re-mate after a single mating episode early in life, sperm are stored in a specialised organ for years but the proximate mechanisms underlying this key physiological adaptation are unknown. We quantified energy metabolism in honeybee sperm and show that the glycolytic metabolite glyceraldehyde-3-phosphate (GA3P) is a key substrate for honeybee sperm survival and energy production. This reliance on non-aerobic energy metabolism in stored sperm was further supported by our findings of very low levels of oxygen inside the spermatheca. Expression of GA3P dehydrogenase (GAPDH), the enzyme involved in catabolism of GA3P, was significantly higher in stored compared to ejaculated sperm. Therefore, long-term sperm storage seems facilitated by the maintenance of non-aerobic energy production, the need for only the ATP-producing steps of glycolysis and by avoiding sperm damage resulting from ROS production. We also confirm that honeybee sperm is capable of aerobic metabolism, which predominates in ejaculated sperm while they compete for access to the spermatheca, but is suppressed during storage. Consequently, the remarkable reproductive traits of honeybees are proximately achieved by differential usage of energy production pathways to maximise competitiveness and minimise damage of sperm.
Collapse
Affiliation(s)
- Ellen Paynter
- Centre for Integrative Bee Research (CIBER), Bayliss Building (M316), The University of Western Australia, 35 Stirling Highway, 6009 Crawley, Western Australia.,ARC Centre of Excellence in Plant Energy Biology, Bayliss Building (M316), The University of Western Australia, 35 Stirling Highway, 6009 Crawley, Western Australia
| | - A Harvey Millar
- Centre for Integrative Bee Research (CIBER), Bayliss Building (M316), The University of Western Australia, 35 Stirling Highway, 6009 Crawley, Western Australia.,ARC Centre of Excellence in Plant Energy Biology, Bayliss Building (M316), The University of Western Australia, 35 Stirling Highway, 6009 Crawley, Western Australia
| | - Mat Welch
- Centre for Integrative Bee Research (CIBER), Bayliss Building (M316), The University of Western Australia, 35 Stirling Highway, 6009 Crawley, Western Australia
| | - Barbara Baer-Imhoof
- Centre for Integrative Bee Research (CIBER), Bayliss Building (M316), The University of Western Australia, 35 Stirling Highway, 6009 Crawley, Western Australia
| | - Danyang Cao
- Centre for Integrative Bee Research (CIBER), Bayliss Building (M316), The University of Western Australia, 35 Stirling Highway, 6009 Crawley, Western Australia.,School of Animal Biology, 35 Stirling Highway, 6009 Crawley, The University of Western Australia, Western Australia
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), Bayliss Building (M316), The University of Western Australia, 35 Stirling Highway, 6009 Crawley, Western Australia.,ARC Centre of Excellence in Plant Energy Biology, Bayliss Building (M316), The University of Western Australia, 35 Stirling Highway, 6009 Crawley, Western Australia
| |
Collapse
|
14
|
Kurze C, Dosselli R, Grassl J, Le Conte Y, Kryger P, Baer B, Moritz RFA. Differential proteomics reveals novel insights into Nosema-honey bee interactions. Insect Biochem Mol Biol 2016; 79:42-49. [PMID: 27784614 DOI: 10.1016/j.ibmb.2016.10.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 10/20/2016] [Accepted: 10/21/2016] [Indexed: 06/06/2023]
Abstract
Host manipulation is a common strategy by parasites to reduce host defense responses, enhance development, host exploitation, reproduction and, ultimately, transmission success. As these parasitic modifications can reduce host fitness, increased selection pressure may result in reciprocal adaptations of the host. Whereas the majority of studies on host manipulation have explored resistance against parasites (i.e. ability to prevent or limit an infection), data describing tolerance mechanisms (i.e. ability to limit harm of an infection) are scarce. By comparing differential protein abundance, we provide evidence of host-parasite interactions in the midgut proteomes of N. ceranae-infected and uninfected honey bees from both Nosema-tolerant and Nosema-sensitive lineages. We identified 16 proteins out of 661 protein spots that were differentially abundant between experimental groups. In general, infections of Nosema resulted in an up-regulation of the bee's energy metabolism. Additionally, we identified 8 proteins that were differentially abundant between tolerant and sensitive honey bees regardless of the Nosema infection. Those proteins were linked to metabolism, response to oxidative stress and apoptosis. In addition to bee proteins, we also identified 3 Nosema ceranae proteins. Interestingly, abundance of two of these Nosema proteins were significantly higher in infected Nosema-sensitive honeybees relative to the infected Nosema-tolerant lineage. This may provide a novel candidate for studying the molecular interplay between N. ceranae and its honey bee host in more detail.
Collapse
Affiliation(s)
- Christoph Kurze
- Martin-Luther-Universität Halle-Wittenberg, Institute for Biology/Molecular Ecology, Hoher Weg 4, 06120 Halle (Saale), Germany; The University of Western Australia, Centre for Integrative Bee Research (CIBER) and ARC Centre of Excellence in Plant Energy Biology, Bayliss Building (M316), Crawley, Western Australia 6009, Australia; Pennsylvania State University, Center for Infectious Disease Dynamics, W249 Millennium Science Complex, University Park, PA 16802, United States.
| | - Ryan Dosselli
- The University of Western Australia, Centre for Integrative Bee Research (CIBER) and ARC Centre of Excellence in Plant Energy Biology, Bayliss Building (M316), Crawley, Western Australia 6009, Australia
| | - Julia Grassl
- The University of Western Australia, Centre for Integrative Bee Research (CIBER) and ARC Centre of Excellence in Plant Energy Biology, Bayliss Building (M316), Crawley, Western Australia 6009, Australia
| | - Yves Le Conte
- INRA, UR 406 Abeilles et Environnement, Site Agroparc, 84914 Avignon Cedex 9, France
| | - Per Kryger
- Aarhus University, Department of Agroecology/Section of Entomology and Plant Pathology, Flakkebjerg, 4200, Slagelse, Denmark
| | - Boris Baer
- The University of Western Australia, Centre for Integrative Bee Research (CIBER) and ARC Centre of Excellence in Plant Energy Biology, Bayliss Building (M316), Crawley, Western Australia 6009, Australia
| | - Robin F A Moritz
- Martin-Luther-Universität Halle-Wittenberg, Institute for Biology/Molecular Ecology, Hoher Weg 4, 06120 Halle (Saale), Germany; German Institute for Integrative Biodiversity Research (iDiv), Bio City, 04103 Leipzig, Germany; University of Pretoria, Department of Zoology and Entomology, Pretoria, 0002, South Africa
| |
Collapse
|
15
|
Dosselli R, Grassl J, Carson A, Simmons LW, Baer B. Flight behaviour of honey bee (Apis mellifera) workers is altered by initial infections of the fungal parasite Nosema apis. Sci Rep 2016; 6:36649. [PMID: 27827404 PMCID: PMC5101476 DOI: 10.1038/srep36649] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 10/19/2016] [Indexed: 11/09/2022] Open
Abstract
Honey bees (Apis mellifera) host a wide range of parasites, some being known contributors towards dramatic colony losses as reported over recent years. To counter parasitic threats, honey bees possess effective immune systems. Because immune responses are predicted to cause substantial physiological costs for infected individuals, they are expected to trade off with other life history traits that ultimately affect the performance and fitness of the entire colony. Here, we tested whether the initial onset of an infection negatively impacts the flight behaviour of honey bee workers, which is an energetically demanding behaviour and a key component of foraging activities. To do this, we infected workers with the widespread fungal pathogen Nosema apis, which is recognised and killed by the honey bee immune system. We compared their survival and flight behaviour with non-infected individuals from the same cohort and colony using radio frequency identification tags (RFID). We found that over a time frame of four days post infection, Nosema did not increase mortality but workers quickly altered their flight behaviour and performed more flights of shorter duration. We conclude that parasitic infections influence foraging activities, which could reduce foraging ranges of colonies and impact their ability to provide pollination services.
Collapse
Affiliation(s)
- Ryan Dosselli
- Centre for Integrative Bee Research (CIBER), ARC Centre of Excellence in Plant Energy Biology, Bayliss Building (M316), The University of Western Australia, Crawley WA 6009, Australia
| | - Julia Grassl
- Centre for Integrative Bee Research (CIBER), ARC Centre of Excellence in Plant Energy Biology, Bayliss Building (M316), The University of Western Australia, Crawley WA 6009, Australia
| | - Andrew Carson
- Centre for Integrative Bee Research (CIBER), ARC Centre of Excellence in Plant Energy Biology, Bayliss Building (M316), The University of Western Australia, Crawley WA 6009, Australia
- Centre for Evolutionary Biology, School of Animal Biology (M092), The University of Western Australia, Crawley WA 6009, Australia
| | - Leigh W. Simmons
- Centre for Evolutionary Biology, School of Animal Biology (M092), The University of Western Australia, Crawley WA 6009, Australia
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), ARC Centre of Excellence in Plant Energy Biology, Bayliss Building (M316), The University of Western Australia, Crawley WA 6009, Australia
| |
Collapse
|
16
|
Peng Y, Grassl J, Millar AH, Baer B. Seminal fluid of honeybees contains multiple mechanisms to combat infections of the sexually transmitted pathogen Nosema apis. Proc Biol Sci 2016; 283:rspb.2015.1785. [PMID: 26791609 DOI: 10.1098/rspb.2015.1785] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The societies of ants, bees and wasps are genetically closed systems where queens only mate during a brief mating episode prior to their eusocial life and males therefore provide queens with a lifetime supply of high-quality sperm. These ejaculates also contain a number of defence proteins that have been detected in the seminal fluid but their function and efficiency have never been investigated in great detail. Here, we used the honeybee Apis mellifera and quantified whether seminal fluid is able to combat infections of the fungal pathogen Nosema apis, a widespread honeybee parasite that is also sexually transmitted. We provide the first empirical evidence that seminal fluid has a remarkable antimicrobial activity against N. apis spores and that antimicrobial seminal fluid components kill spores in multiple ways. The protein fraction of seminal fluid induces extracellular spore germination, which disrupts the life cycle of N. apis, whereas the non-protein fraction of seminal fluid induces a direct viability loss of intact spores. We conclude that males provide their ejaculates with efficient antimicrobial molecules that are able to kill N. apis spores and thereby reduce the risk of disease transmission during mating. Our findings could be of broader significance to master honeybee diseases in managed honeybee stock in the future.
Collapse
Affiliation(s)
- Yan Peng
- Centre for Integrative Bee Research (CIBER) and ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Bayliss Building (M316), Crawley, Western Australia 6009, Australia
| | - Julia Grassl
- Centre for Integrative Bee Research (CIBER) and ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Bayliss Building (M316), Crawley, Western Australia 6009, Australia
| | - A Harvey Millar
- Centre for Integrative Bee Research (CIBER) and ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Bayliss Building (M316), Crawley, Western Australia 6009, Australia
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER) and ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Bayliss Building (M316), Crawley, Western Australia 6009, Australia
| |
Collapse
|
17
|
Grassl J, Peng Y, Baer-Imhoof B, Welch M, Millar AH, Baer B. Infections with the Sexually Transmitted Pathogen Nosema apis Trigger an Immune Response in the Seminal Fluid of Honey Bees (Apis mellifera). J Proteome Res 2016; 16:319-334. [DOI: 10.1021/acs.jproteome.6b00051] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Julia Grassl
- Centre for Integrative Bee Research
(CIBER) and ARC Centre of Excellence
in Plant Energy Biology and ‡School of Animal Biology, The University of Western Australia, Bayliss Building, Crawley, WA 6009, Australia
| | - Yan Peng
- Centre for Integrative Bee Research
(CIBER) and ARC Centre of Excellence
in Plant Energy Biology and ‡School of Animal Biology, The University of Western Australia, Bayliss Building, Crawley, WA 6009, Australia
| | - Barbara Baer-Imhoof
- Centre for Integrative Bee Research
(CIBER) and ARC Centre of Excellence
in Plant Energy Biology and ‡School of Animal Biology, The University of Western Australia, Bayliss Building, Crawley, WA 6009, Australia
| | - Mat Welch
- Centre for Integrative Bee Research
(CIBER) and ARC Centre of Excellence
in Plant Energy Biology and ‡School of Animal Biology, The University of Western Australia, Bayliss Building, Crawley, WA 6009, Australia
| | - A. Harvey Millar
- Centre for Integrative Bee Research
(CIBER) and ARC Centre of Excellence
in Plant Energy Biology and ‡School of Animal Biology, The University of Western Australia, Bayliss Building, Crawley, WA 6009, Australia
| | - Boris Baer
- Centre for Integrative Bee Research
(CIBER) and ARC Centre of Excellence
in Plant Energy Biology and ‡School of Animal Biology, The University of Western Australia, Bayliss Building, Crawley, WA 6009, Australia
| |
Collapse
|
18
|
Baer B, Collins J, Maalaps K, den Boer SPA. Sperm use economy of honeybee (Apis mellifera) queens. Ecol Evol 2016; 6:2877-85. [PMID: 27217944 PMCID: PMC4863013 DOI: 10.1002/ece3.2075] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 02/19/2016] [Accepted: 02/22/2016] [Indexed: 11/09/2022] Open
Abstract
The queens of eusocial ants, bees, and wasps only mate during a very brief period early in life to acquire and store a lifetime supply of sperm. As sperm cannot be replenished, queens have to be highly economic when using stored sperm to fertilize eggs, especially in species with large and long‐lived colonies. However, queen fertility has not been studied in detail, so that we have little understanding of how economic sperm use is in different species, and whether queens are able to influence their sperm use. This is surprising given that sperm use is a key factor of eusocial life, as it determines the fecundity and longevity of queens and therefore colony fitness. We quantified the number of sperm that honeybee (Apis mellifera) queens use to fertilize eggs. We examined sperm use in naturally mated queens of different ages and in queens artificially inseminated with different volumes of semen. We found that queens are remarkably efficient and only use a median of 2 sperm per egg fertilization, with decreasing sperm use in older queens. The number of sperm in storage was always a significant predictor for the number of sperm used per fertilization, indicating that queens use a constant ratio of spermathecal fluid relative to total spermathecal volume of 2.364 × 10−6 to fertilize eggs. This allowed us to calculate a lifetime fecundity for honeybee queens of around 1,500,000 fertilized eggs. Our data provide the first empirical evidence that honeybee queens do not manipulate sperm use, and fertilization failures in worker‐destined eggs are therefore honest signals that workers can use to time queen replacement, which is crucial for colony performance and fitness.
Collapse
Affiliation(s)
- Boris Baer
- Centre for Integrative Bee Research (CIBER) ARC Centre of Excellence in Plant Energy Biology The University of Western Australia MCS Building M310 6009 Western Australia Crawley Australia
| | - Jason Collins
- Business School The University of Western Australia Building M252 6009 Western Australia Crawley Australia
| | - Kristiina Maalaps
- Centre for Integrative Bee Research (CIBER) ARC Centre of Excellence in Plant Energy Biology The University of Western Australia MCS Building M310 6009 Western Australia Crawley Australia
| | - Susanne P A den Boer
- Centre for Integrative Bee Research (CIBER) ARC Centre of Excellence in Plant Energy Biology The University of Western Australia MCS Building M3106009 Western Australia Crawley Australia; Department of Biology Centre for Social Evolution University of Copenhagen Universitetsparken 152100 Copenhagen Denmark
| |
Collapse
|
19
|
Abstract
Evolutionary ecologists are traditionally gene-focused, as genes propagate phenotypic traits across generations and mutations and recombination in the DNA generate genetic diversity required for evolutionary processes. As a consequence, the inheritance of changed DNA provides a molecular explanation for the functional changes associated with natural selection. A direct focus on proteins on the other hand, the actual molecular agents responsible for the expression of a phenotypic trait, receives far less interest from ecologists and evolutionary biologists. This is partially due to the central dogma of molecular biology that appears to define proteins as the 'dead-end of molecular information flow' as well as technical limitations in identifying and studying proteins and their diversity in the field and in many of the more exotic genera often favored in ecological studies. Here we provide an overview of a newly forming field of research that we refer to as 'Evolutionary Proteomics'. We point out that the origins of cellular function are related to the properties of polypeptide and RNA and their interactions with the environment, rather than DNA descent, and that the critical role of horizontal gene transfer in evolution is more about coopting new proteins to impact cellular processes than it is about modifying gene function. Furthermore, post-transcriptional and post-translational processes generate a remarkable diversity of mature proteins from a single gene, and the properties of these mature proteins can also influence inheritance through genetic and perhaps epigenetic mechanisms. The influence of post-transcriptional diversification on evolutionary processes could provide a novel mechanistic underpinning for elements of rapid, directed evolutionary changes and adaptations as observed for a variety of evolutionary processes. Modern state-of the art technologies based on mass spectrometry are now available to identify and quantify peptides, proteins, protein modifications and protein interactions of interest with high accuracy and assess protein diversity and function. Therefore, proteomic technologies can be viewed as providing evolutionary biologist with exciting novel opportunities to understand very early events in functional variation of cellular molecular machinery that are acting as part of evolutionary processes.
Collapse
Affiliation(s)
- B Baer
- Centre for Integrative Bee Research (CIBER) and ARC Centre of Excellence in Plant Energy Biology, Bayliss Building, The University of Western Australia, 6009 Crawley, Australia.
| | - A H Millar
- Centre for Integrative Bee Research (CIBER) and ARC Centre of Excellence in Plant Energy Biology, Bayliss Building, The University of Western Australia, 6009 Crawley, Australia
| |
Collapse
|
20
|
Baer B, Nguyen M, Woo EJ, Winiecki S, Scott J, Martin D, Botsis T, Ball R. Can Natural Language Processing Improve the Efficiency of Vaccine Adverse Event Report Review? Methods Inf Med 2015; 55:144-50. [PMID: 26394725 DOI: 10.3414/me14-01-0066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 06/30/2015] [Indexed: 11/09/2022]
Abstract
BACKGROUND Individual case review of spontaneous adverse event (AE) reports remains a cornerstone of medical product safety surveillance for industry and regulators. Previously we developed the Vaccine Adverse Event Text Miner (VaeTM) to offer automated information extraction and potentially accelerate the evaluation of large volumes of unstructured data and facilitate signal detection. OBJECTIVE To assess how the information extraction performed by VaeTM impacts the accuracy of a medical expert's review of the vaccine adverse event report. METHODS The "outcome of interest" (diagnosis, cause of death, second level diagnosis), "onset time," and "alternative explanations" (drug, medical and family history) for the adverse event were extracted from 1000 reports from the Vaccine Adverse Event Reporting System (VAERS) using the VaeTM system. We compared the human interpretation, by medical experts, of the VaeTM extracted data with their interpretation of the traditional full text reports for these three variables. Two experienced clinicians alternately reviewed text miner output and full text. A third clinician scored the match rate using a predefined algorithm; the proportion of matches and 95% confidence intervals (CI) were calculated. Review time per report was analyzed. RESULTS Proportion of matches between the interpretation of the VaeTM extracted data, compared to the interpretation of the full text: 93% for outcome of interest (95% CI: 91-94%) and 78% for alternative explanation (95% CI: 75-81%). Extracted data on the time to onset was used in 14% of cases and was a match in 54% (95% CI: 46-63%) of those cases. When supported by structured time data from reports, the match for time to onset was 79% (95% CI: 76-81%). The extracted text averaged 136 (74%) fewer words, resulting in a mean reduction in review time of 50 (58%) seconds per report. CONCLUSION Despite a 74% reduction in words, the clinical conclusion from VaeTM extracted data agreed with the full text in 93% and 78% of reports for the outcome of interest and alternative explanation, respectively. The limited amount of extracted time interval data indicates the need for further development of this feature. VaeTM may improve review efficiency, but further study is needed to determine if this level of agreement is sufficient for routine use.
Collapse
Affiliation(s)
- B Baer
- Bethany Baer, FDA Center for Biologics Evaluation and Research, 10903 New Hampshire Ave, WO71-1323, Silver Spring, MD 20993-0002, 240-402-8584, USA, E-mail:
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Shaw J, Boyd A, House M, Woodward R, Mathes F, Cowin G, Saunders M, Baer B. Magnetic particle-mediated magnetoreception. J R Soc Interface 2015; 12:0499. [PMID: 26333810 PMCID: PMC4614459 DOI: 10.1098/rsif.2015.0499] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 08/12/2015] [Indexed: 11/12/2022] Open
Abstract
Behavioural studies underpin the weight of experimental evidence for the existence of a magnetic sense in animals. In contrast, studies aimed at understanding the mechanistic basis of magnetoreception by determining the anatomical location, structure and function of sensory cells have been inconclusive. In this review, studies attempting to demonstrate the existence of a magnetoreceptor based on the principles of the magnetite hypothesis are examined. Specific attention is given to the range of techniques, and main animal model systems that have been used in the search for magnetite particulates. Anatomical location/cell rarity and composition are identified as two key obstacles that must be addressed in order to make progress in locating and characterizing a magnetite-based magnetoreceptor cell. Avenues for further study are suggested, including the need for novel experimental, correlative, multimodal and multidisciplinary approaches. The aim of this review is to inspire new efforts towards understanding the cellular basis of magnetoreception in animals, which will in turn inform a new era of behavioural research based on first principles.
Collapse
Affiliation(s)
- Jeremy Shaw
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Alastair Boyd
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Michael House
- School of Physics, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Robert Woodward
- School of Physics, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Falko Mathes
- School of Earth and Environment, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Gary Cowin
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Martin Saunders
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), The University of Western Australia, Perth, Western Australia 6009, Australia
| |
Collapse
|
22
|
Lach L, Kratz M, Baer B. Parasitized honey bees are less likely to forage and carry less pollen. J Invertebr Pathol 2015; 130:64-71. [DOI: 10.1016/j.jip.2015.06.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 06/18/2015] [Accepted: 06/30/2015] [Indexed: 01/04/2023]
|
23
|
den Boer SPA, Stürup M, Boomsma JJ, Baer B. The ejaculatory biology of leafcutter ants. J Insect Physiol 2015; 74:56-62. [PMID: 25702828 DOI: 10.1016/j.jinsphys.2015.02.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 02/10/2015] [Accepted: 02/13/2015] [Indexed: 06/04/2023]
Abstract
The eusocial ants are unique in that females (queens) acquire and store sperm on a single mating flight early in adult life. This event largely determines the size (possibly millions of workers), longevity (possibly decades) and genetic variation of the colonies that queens found, but our understanding of the fundamental biology of ejaculate production, transfer and physiological function remains extremely limited. We studied the ejaculation process in the leafcutter ant Atta colombica and found that it starts with the appearance of a clear pre-ejaculatory fluid (PEF) at the tip of the endophallus that is followed by the joint expulsion of the remainder of accessory gland (AG) secretion, sperm, accessory testes (AT) secretion, and a small mating plug. PEF, AG secretion and AT secretion all contribute to sperm survival, but PEF and AG secretion also reduce the survival of sperm from other males. We show that PEF is produced in the AGs and is likely identical to AG secretion because protein-banding patterns of PEF and AG secretion were similar on 1D electrophoresis gels, but differed from the protein-banding pattern of AT secretion. We show that proteins in AG secretion are responsible for the incapacitation of rival sperm and infer that transfer of AG secretion prior to sperm may allow these components to interact with rival sperm, while at the same time providing a supportive biochemical environment for the arrival of own sperm.
Collapse
Affiliation(s)
- Susanne P A den Boer
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark; Centre for Integrative Bee Research (CIBER), ARC CoE in Plant Energy Biology, The University of Western Australia, M316, 35 Stirling Highway, 6009 Crawley, Australia.
| | - Marlene Stürup
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Jacobus J Boomsma
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), ARC CoE in Plant Energy Biology, The University of Western Australia, M316, 35 Stirling Highway, 6009 Crawley, Australia
| |
Collapse
|
24
|
Hoppe PP, Safer A, Amaral-Rogers V, Bonmatin JM, Goulson D, Menzel R, Baer B. Effects of a neonicotinoid pesticide on honey bee colonies: a response to the field study by Pilling et al. (2013). Environ Sci Eur 2015; 27:28. [PMID: 27752429 PMCID: PMC5045128 DOI: 10.1186/s12302-015-0060-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 10/24/2015] [Indexed: 05/20/2023]
Abstract
Our assessment of the multi-year overwintering study by Pilling et al. (2013) revealed a number of major deficiencies regarding the study design, the protocol and the evaluation of results. Colonies were exposed for short periods per year to flowering oilseed rape and maize grown from thiamethoxam-coated seeds. Thiamethoxam as the sole active ingredient was used, not a more efficacious commercial product, at seed treatment rates that were lower than recommended as per common agricultural practices. Design and adherence to the protocol were described inadequately making it doubtful whether the study was implemented in a traceable way. No results are given for overwintering losses. Much emphasis is laid on presenting condensed raw data but no statistical evaluation is provided. Therefore, the work presented does not contribute new knowledge to our understanding of the potential impact of thiamethoxam products under field conditions. Furthermore, the authors express concern over the refereeing process of the paper. Publications in refereed journals are likely to be taken seriously in political debates and policy-making, and so must be based on truthful data and methodologies.
Collapse
Affiliation(s)
| | - Anton Safer
- Institute of Public Health, Ruprecht-Karls-University, INF324, 69120 Heidelberg, Germany
| | - Vanessa Amaral-Rogers
- Buglife-The Invertebrate Conservation Trust, Bug House Ham Lane, Orton Waterville, Peterborough, PE2 5UU UK
| | - Jean-Marc Bonmatin
- CNRS Center for Molecular Biophysics CBM, Rue Charles Sadron, 45071 Orleans Cedex 2, France
| | - Dave Goulson
- School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG UK
| | - Randolph Menzel
- Institute for Biology, Neurobiology, Free University of Berlin, Königin-Luise-Str. 28/30, 14195 Berlin, Germany
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), ARC Centre of Excellence in Plant Energy Biology, Bayliss Building, The University of Western Australia, Crawley, 6009 Australia
| |
Collapse
|
25
|
Paynter E, Baer-Imhoof B, Linden M, Lee-Pullen T, Heel K, Rigby P, Baer B. Flow cytometry as a rapid and reliable method to quantify sperm viability in the honeybeeApis mellifera. Cytometry A 2014; 85:463-72. [DOI: 10.1002/cyto.a.22462] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Revised: 02/27/2014] [Accepted: 03/04/2014] [Indexed: 11/08/2022]
Affiliation(s)
- Ellen Paynter
- Centre for Integrative Bee Research (CIBER), ARC CoE Plant Energy Biology, MCS Building M316, The University of Western Australia; 6009 Crawley Australia
| | - Barbara Baer-Imhoof
- Centre for Integrative Bee Research (CIBER), ARC CoE Plant Energy Biology, MCS Building M316, The University of Western Australia; 6009 Crawley Australia
| | - Matthew Linden
- Centre for Microscopy, Characterisation and Analysis, QEII Medical Centre M510, The University of Western Australia; 6009 Crawley Australia
| | - Tracey Lee-Pullen
- Centre for Microscopy, Characterisation and Analysis, QEII Medical Centre M510, The University of Western Australia; 6009 Crawley Australia
| | - Kathy Heel
- Centre for Microscopy, Characterisation and Analysis, QEII Medical Centre M510, The University of Western Australia; 6009 Crawley Australia
- The School of Pathology and Laboratory Medicine M504; The University of Western Australia; 6009 Crawley Australia
| | - Paul Rigby
- Centre for Microscopy, Characterisation and Analysis, QEII Medical Centre M510, The University of Western Australia; 6009 Crawley Australia
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), ARC CoE Plant Energy Biology, MCS Building M316, The University of Western Australia; 6009 Crawley Australia
- Centre for Evolutionary Biology, School of Animal Biology M092; The University of Western Australia; 6009 Crawley Australia
| |
Collapse
|
26
|
Peng Y, Lee-Pullen TF, Heel K, Millar AH, Baer B. Quantifying spore viability of the honey bee pathogenNosema apisusing flow cytometry. Cytometry A 2013; 85:454-62. [DOI: 10.1002/cyto.a.22428] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 10/30/2013] [Accepted: 11/26/2013] [Indexed: 12/11/2022]
Affiliation(s)
- Yan Peng
- Centre for Integrative Bee Research (CIBER); The University of Western Australia; Crawley Western Australia 6009 Australia
- ARC Centre of Excellence in Plant Energy and Centre for Comparative Analysis of Biomolecular Networks (CABIN); The University of Western Australia; Crawley Western Australia 6009 Australia
| | - Tracey F. Lee-Pullen
- Centre for Microscopy, Characterisation and Analysis; The University of Western Australia; Crawley Western Australia 6009 Australia
| | - Kathy Heel
- Centre for Microscopy, Characterisation and Analysis; The University of Western Australia; Crawley Western Australia 6009 Australia
| | - A. Harvey Millar
- Centre for Integrative Bee Research (CIBER); The University of Western Australia; Crawley Western Australia 6009 Australia
- ARC Centre of Excellence in Plant Energy and Centre for Comparative Analysis of Biomolecular Networks (CABIN); The University of Western Australia; Crawley Western Australia 6009 Australia
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER); The University of Western Australia; Crawley Western Australia 6009 Australia
- ARC Centre of Excellence in Plant Energy and Centre for Comparative Analysis of Biomolecular Networks (CABIN); The University of Western Australia; Crawley Western Australia 6009 Australia
| |
Collapse
|
27
|
Zareie R, Eubel H, Millar AH, Baer B. Long-Term Survival of High Quality Sperm: Insights into the Sperm Proteome of the Honeybee Apis mellifera. J Proteome Res 2013; 12:5180-8. [DOI: 10.1021/pr4004773] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Holger Eubel
- Institute
for Plant Genetics, Department of Plant Proteomcis, Leibniz University Hannover, 30419 Hannover, Germany
| | | | | |
Collapse
|
28
|
Sturup M, Baer-Imhoof B, Nash DR, Boomsma JJ, Baer B. When every sperm counts: factors affecting male fertility in the honeybee Apis mellifera. Behav Ecol 2013. [DOI: 10.1093/beheco/art049] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
29
|
Baer B, Zareie R, Paynter E, Poland V, Millar AH. Seminal fluid proteins differ in abundance between genetic lineages of honeybees. J Proteomics 2012; 75:5646-53. [DOI: 10.1016/j.jprot.2012.08.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 07/19/2012] [Accepted: 08/03/2012] [Indexed: 11/25/2022]
|
30
|
Jaffé R, Garcia-Gonzalez F, den Boer SPA, Simmons LW, Baer B. Patterns of paternity skew among polyandrous social insects: what can they tell us about the potential for sexual selection? Evolution 2012. [PMID: 23206136 DOI: 10.1111/j.1558-5646.2012.01721.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Monogamy results in high genetic relatedness among offspring and thus it is generally assumed to be favored by kin selection. Female multiple mating (polyandry) has nevertheless evolved several times in the social Hymenoptera (ants, bees, and wasps), and a substantial amount of work has been conducted to understand its costs and benefits. Relatedness and inclusive fitness benefits are, however, not only influenced by queen mating frequency but also by paternity skew, which is a quantitative measure of paternity biases among the offspring of polyandrous females. We performed a large-scale phylogenetic analysis of paternity skew across polyandrous social Hymenoptera. We found a general and significant negative association between paternity frequency and paternity skew. High paternity skew, which increases relatedness among colony members and thus maximizes inclusive fitness gains, characterized species with low paternity frequency. However, species with highly polyandrous queens had low paternity skew, with paternity equalized among potential sires. Equal paternity shares among fathers are expected to maximize fitness benefits derived from genetic diversity among offspring. We discuss the potential for postcopulatory sexual selection to influence patterns of paternity in social insects, and suggest that sexual selection may have played a key, yet overlooked role in social evolution.
Collapse
Affiliation(s)
- Rodolfo Jaffé
- Centre for Evolutionary Biology, The University of Western Australia, M092, 35 Stirling Highway, 6009 Crawley, Australia.
| | | | | | | | | |
Collapse
|
31
|
|
32
|
King M, Eubel H, Millar AH, Baer B. Proteins within the seminal fluid are crucial to keep sperm viable in the honeybee Apis mellifera. J Insect Physiol 2011; 57:409-414. [PMID: 21192944 DOI: 10.1016/j.jinsphys.2010.12.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 12/20/2010] [Accepted: 12/21/2010] [Indexed: 05/30/2023]
Abstract
Seminal fluid is a biochemically complex mixture of glandular secretions that is transferred to the females sexual tract as part of the ejaculate. Seminal fluid has received increasing scientific interest in the fields of evolutionary and reproductive biology, as it seems a major determinant of male fertility/infertility and reproductive success. Here we used the honeybee Apis mellifera, where seminal fluid can be collected as part of a male's ejaculate, and performed a series of experiments to investigate the effects of seminal fluid and its components on sperm viability. We show that honeybee seminal fluid is highly potent in keeping sperm alive and this positive effect is present over a 24h time span, comparable to the timing of the sperm storage process in the queen. We furthermore show that the presence of proteins within the seminal fluid and their structural integrity are crucial for this effect. Finally, we activated sperm using fructose and provide evidence that the positive effect of seminal fluid proteins on sperm survival cannot be replicated using generic protein substitutes. Our data provide experimental insights into the complex molecular interplay between sperm and seminal fluid defining male fertility and reproductive success.
Collapse
Affiliation(s)
- Michaela King
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 6009 Crawley, Australia
| | | | | | | |
Collapse
|
33
|
Abstract
Genetic diversity in workers influences colony immunity in several species of eusocial insects. Much less work has been conducted to test for comparable effects of worker heterozygosity, a measure of genetic diversity within an individual. Here we present a field study using the honeybee (Apis mellifera) and sampled foraging workers throughout Western Australia. Samples were taken from feral and managed colonies, aiming to maximise the variation in worker and colony heterozygosity. We quantified worker heterozygosity using microsatellites, and tested the idea that individual worker heterozygosity predicts immune response, measured as the enzymatic activity of an antimicrobial peptide phenoloxidase (PO) and encapsulation response. We found substantial variation in worker heterozygosity, but no significant effects of heterozygosity on PO activity or encapsulation response, either on the individual or colony level. Heterozygosity was found to be higher in workers of feral colonies compared with managed colonies. Colonies kept in husbandry, as compared with colonies from the field, had significantly higher levels of PO activity and encapsulation response, providing evidence for substantial environmental effects on individual and colony immunity.
Collapse
|
34
|
Brodmann PA, Reyer HU, Baer B. The Relative Importance of Habitat Structure and of Prey Characteristics for the Foraging Success of Water Pipits (Anthus spinoletta)*. Ethology 2010. [DOI: 10.1111/j.1439-0310.1997.tb00118.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
35
|
Abstract
Queens of ants and bees normally obtain a lifetime supply of sperm on a single day of sexual activity, and sperm competition is expected to occur in lineages where queens receive sperm from multiple males. We compared singly mated (monandrous) and multiply mated (polyandrous) sister groups of ants and bees and show that seminal fluid of polyandrous species has a more positive effect on the survival of a male's own sperm than on other males' sperm. This difference was not observed in the monandrous species, suggesting that incapacitation of competing sperm may have independently evolved in both bees and ants. In Atta leafcutter ants, the negative effect of the seminal fluid of other males was negated by secretion from the queen sperm-storage organ, suggesting that queens may control ejaculate competition after sperm storage.
Collapse
Affiliation(s)
- Susanne P A den Boer
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | | | | |
Collapse
|
36
|
Abstract
In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps), reproduction is usually monopolized by one or relatively few queens, who mate only during a brief period early in life and store sperm for later use. The queens of some ants are particularly long-lived and have the potential to produce millions of offspring during their life. To do so, queens store many sperm cells, and this sperm must remain viable throughout the years of storage. Queens should also be under strong selection to use stored sperm prudently when fertilizing eggs. We used the leaf-cutter ant Atta colombica to investigate the dynamics of sperm use during egg fertilization. We show that queens are able to fertilize close to 100 per cent of the eggs and that the average sperm use per egg is very low, but increases with queen age. The robustness of stored sperm was found to decrease with years of storage, signifying that senescence affects sperm either directly or indirectly via the declining glandular secretions or deteriorating sperm-storage organs. We evaluate our findings with a heuristic model, which suggests that the average queen has sperm for almost 9 years of normal colony development. We discuss the extent to which leaf-cutter ant queens have been able to optimize their sperm expenditure and infer that our observed averages of sperm number, sperm robustness and sperm use are consistent with sperm depletion being a significant cause of mortality of mature colonies of Atta leaf-cutter ants.
Collapse
Affiliation(s)
- Susanne P A den Boer
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark.
| | | | | | | | | | | |
Collapse
|
37
|
Abstract
Ejaculates contain sperm but also seminal fluid, which is increasingly recognized to be of central importance for reproductive success. However, a detailed biochemical composition and physiological understanding of seminal fluid is still elusive. We have used MS to identify the 57 most abundant proteins within the ejaculated seminal fluid of the honeybee Apis mellifera. Their amino acid sequences revealed the presence of diverse functional categories of enzymes, regulators and structural proteins. A number have known or predicted roles in maintaining sperm viability, protecting sperm from microbial infections or interacting with the physiology of the female. A range of putative glycoproteins or glycosylation enzymes were detected among the 57, subsequent fluorescent staining of glycolysation revealed several prominent glycoproteins in seminal fluid, while no glycoproteins were detected in sperm samples. Many of the abundant proteins that accumulate in the seminal fluid did not contain predictable tags for secretion for the cell. Comparison of the honeybee seminal fluid proteins with Drosophila seminal fluid proteins (including secreted accessory gland proteins known as ACPs), and with the human seminal fluid proteome revealed the bee protein set contains a range of newly identified seminal fluid proteins and we noted more similarity of the bee protein set with the current human seminal fluid protein set than with the known Drosophila seminal fluid proteins. The honeybee seminal fluid proteome thus represents an important addition to available data for comparative studies of seminal fluid proteomes in insects.
Collapse
Affiliation(s)
- Boris Baer
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, Australia.
| | | | | | | | | |
Collapse
|
38
|
Baer B, Eubel H, Taylor NL, O'Toole N, Millar AH. Insights into female sperm storage from the spermathecal fluid proteome of the honeybee Apis mellifera. Genome Biol 2009; 10:R67. [PMID: 19538722 PMCID: PMC2718501 DOI: 10.1186/gb-2009-10-6-r67] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 05/06/2009] [Accepted: 06/18/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Female animals are often able to store sperm inside their body--in some species even for several decades. The molecular basis of how females keep non-own cells alive is largely unknown, but since sperm cells are reported to be transcriptionally silenced and, therefore, limited in their ability to maintain their own function, it is likely that females actively participate in sperm maintenance. Because female contributions are likely to be of central importance for sperm survival, molecular insights into the process offer opportunities to observe mechanisms through which females manipulate sperm. RESULTS We used the honeybee, Apis mellifera, in which queens are highly polyandrous and able to maintain sperm viable for several years. We identified over a hundred proteins representing the major constituents of the spermathecal fluid, which females contribute to sperm in storage. We found that the gel profile of proteins from spermathecal fluid is very similar to the secretions of the spermathecal gland and concluded that the spermathecal glands are the main contributors to the spermathecal fluid proteome. A detailed analysis of the spermathecal fluid proteins indicate that they fall into a range of different functional groups, most notably enzymes of energy metabolism and antioxidant defense. A metabolic network analysis comparing the proteins detected in seminal fluid and spermathecal fluid showed a more integrated network is present in the spermathecal fluid that could facilitate long-term storage of sperm. CONCLUSIONS We present a large-scale identification of proteins in the spermathecal fluid of honeybee queens and provide insights into the molecular regulation of female sperm storage.
Collapse
Affiliation(s)
- Boris Baer
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Stirling Hwy, Crawley WA 6009, Australia
- Centre for Evolutionary Biology, School of Animal Biology, The University of Western Australia, Stirling Hwy, Crawley WA 6009, Australia
| | - Holger Eubel
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Stirling Hwy, Crawley WA 6009, Australia
| | - Nicolas L Taylor
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Stirling Hwy, Crawley WA 6009, Australia
| | - Nicholas O'Toole
- Centre of Excellence for Computational Systems Biology, The University of Western Australia, Stirling Hwy, Crawley WA 6009, Australia
| | - A Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Stirling Hwy, Crawley WA 6009, Australia
| |
Collapse
|
39
|
den Boer SPA, Boomsma JJ, Baer B. Honey bee males and queens use glandular secretions to enhance sperm viability before and after storage. J Insect Physiol 2009; 55:538-543. [PMID: 19232404 DOI: 10.1016/j.jinsphys.2009.01.012] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Revised: 01/13/2009] [Accepted: 01/23/2009] [Indexed: 05/27/2023]
Abstract
Internal fertilization requires live sperm to be transferred from male to female before egg fertilization. Both males and females assist the insemination process by providing sperm with glandular secretions, which have been inferred to contain subsets of proteins that maintain sperm viability. Here we show that in the honeybee (Apis mellifera) secretions of the male accessory glands, the major contributors towards seminal fluid, enhance sperm survival. We further demonstrate that the protein fraction of the male accessory gland secretion is indeed important for achieving the maximal effect on sperm survival. After sperm storage, the queens also provide sperm with secretions from spermathecal glands and we show that these secretions have a comparable positive effect on sperm viability. SDS gels show that the proteomic profiles of accessory gland secretion and spermathecal fluid secretion hardly overlap, which suggests that males and females use different proteins to enhance sperm viability during, respectively, ejaculation and final sperm storage.
Collapse
Affiliation(s)
- Susanne P A den Boer
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | | | | |
Collapse
|
40
|
|
41
|
Abstract
The genetic architecture of fitness-relevant traits in natural populations is a topic that has remained almost untouched by quantitative genetics. Given the importance of parasitism for the host's fitness, we used QTL mapping to study the genetic architecture of traits relevant for host-parasite interactions in the trypanosome parasite, Crithidia bombi and its host, Bombus terrestris. The three traits analysed were the parasite's infection intensity, the strength of the general immune response (measured as the encapsulation of a novel antigen) and body size. The genetic architecture of these traits was examined in three natural, unmanipulated mapping populations of B. terrestris. Our results indicate that the intracolonial phenotypic variation of all three traits is based on a network of QTLs and epistatic interactions. While these networks are similar between mapping populations in complexity and number of QTLs, as well as in their epistatic interactions, the variability in the position of QTL and the interacting loci was high. Only one QTL for body size was plausibly found in at least two populations. QTLs for encapsulation and Crithidia infection intensity were located on the same linkage groups.
Collapse
Affiliation(s)
- L Wilfert
- ETH Zürich, Institute for Integrative Biology (IBZ), Experimental Ecology Group, ETH-Zentrum CHN, CH-8092 Zürich, Switzerland.
| | | | | | | |
Collapse
|
42
|
Abstract
Copulation behavior has often been shaped by sexually selected sperm competition or cryptic female choice. However, manipulation of previously deposited ejaculates is unknown in the social Hymenoptera and the degree to which sperm competes after insemination or is actively selected by females has remained ambiguous. We studied the mating process in the leaf-cutting ants Atta colombica and A. cephalotes, which belong to one of the few derived social insect lineages where obligate multiple mating has evolved. As copulations often occur at night and in remote places, direct observations were impossible, so we had to reconstruct the sequential copulation events by morphological analysis of the male and female genitalia and by tracking the process of sperm transfer and sperm storage. We show that Atta male genitalia have two external rows of spiny teeth, which fit into a specialized pouch organ in the female sexual tract. Reconstruction of the sperm storage process indicated that sperm is transferred to the spermatheca during or immediately after ejaculation and without being mixed with sperm and seminal fluids from other males. A convergent mechanism of direct sperm transfer to the spermatheca of queens is known from two species of dwarf honeybees. Direct sperm transfer may restrict female control over the sperm storage process and the number of males that contribute to the stored sperm.
Collapse
Affiliation(s)
- Boris Baer
- Institute of Biology, Department of Population Biology, Universitetsparken 15, 2100 Copenhagen, Denmark.
| | | |
Collapse
|
43
|
Abstract
Ant queens are among the most long-lived insects known. They mate early in adult life and maintain millions of viable sperm in their sperm storage organ until they die many years later. Because they never re-mate, the reproductive success of queens is ultimately sperm-limited, but it is not known what selective forces determine the upper limit to sperm storage. Here we show that sperm storage carries a significant cost of reduced immunity during colony founding. Newly mated queens of the leaf-cutting ant Atta colombica upregulate their immune response shortly after completing their nest burrow, probably as an adaptive response to a greater exposure to pathogens in the absence of grooming workers. However, the immune response nine days after colony founding is negatively correlated with the amount of sperm in the sperm storage organ, indicating that short-term survival is traded off against long-term reproductive success. The immune response was lower when more males contributed to the stored sperm, indicating that there might be an additional cost of mating or storing genetically different ejaculates.
Collapse
Affiliation(s)
- Boris Baer
- Institute of Biology, Department of Population Biology, Universitetsparken 15, 2100 Copenhagen, Denmark.
| | | | | |
Collapse
|
44
|
Affiliation(s)
- D J Ralston
- Laboratory of Comparative Biology, Kaiser Foundation Research Institute, Richmond, California
| | | |
Collapse
|
45
|
Baer B, de Jong G, Schmid-Hempel R, Schmid-Hempel P, Høeg JT, Boomsma JJ. Heritability of sperm length in the bumblebee Bombus terrestris. Genetica 2006; 127:11-23. [PMID: 16850209 DOI: 10.1007/s10709-005-2157-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2005] [Accepted: 08/13/2005] [Indexed: 10/24/2022]
Abstract
Sperm length is highly variable, both between and within species, but the evolutionary significance of this variation is poorly understood. Sexual selection on sperm length requires a significant additive genetic variance, but few studies have actually measured this. Here we present the first estimates of narrow sense heritability of sperm length in a social insect, the bumblebee Bombus terrestris. In spite of a balanced and straightforward rearing design of colonies, and the possibility to replicate measurements of sperm within single males nested within colonies, the analysis proved to be complex. Several appropriate statistical models were derived, each depending on different assumptions. The heritability estimates obtained ranged from h (2) = 0.197 +/- 0.091 to h (2) = 0.429 +/- 0.154. All our estimates were substantially lower than previous estimates of sperm length heritability in non-social insects and vertebrates.
Collapse
Affiliation(s)
- Boris Baer
- Department of Population Biology, Institute of Biology, Universitetsparken 15, 2100, Copenhagen, Denmark.
| | | | | | | | | | | |
Collapse
|
46
|
Abstract
We present evidence that in the absence of the transfer of male gland compounds in the ejaculate as well as of behavioural male traits, such as mate guarding or harming of females, sperm itself affects female life-history traits such as hibernation success, female longevity and female fitness. Using the bumble-bee Bombus terrestris, we artificially inseminated queens (females) with sperm from one or several males and show that sire groups (groups of brother males) vary in their effects on queen hibernation survival, longevity and fitness. In addition, multiply inseminated queens always had a lower performance as compared to singly inseminated queens. Apart from these main effects, sire groups (in situations of multiple insemination) affected queen longevity and fitness not independently of each other, i.e. certain sire group combinations were more harmful to queens than others. So far, the cause(s) of these effects remain(s) elusive. Harmful male traits as detected here are not necessarily expected to evolve in social insects because males depend on females for a successful completion of a colony cycle and thus have strong convergent interests with their mates.
Collapse
Affiliation(s)
- Boris Baer
- Copenhagen University, Institute of Biology, Department for Population Biology, 2100 Copenhagen, Denmark.
| | | |
Collapse
|
47
|
Abstract
Pair formation in social insects mostly happens early in adult life and away from the social colony context, which precludes promiscuity in the usual sense. Termite males have continuous sperm production, but males of social Hymenoptera have fixed complements of sperm, except for a few species that mate before female dispersal and show male-fighting and lifelong sperm production. We develop an evolutionary framework for testing sexual selection and sperm competition theory across the advanced eusocial insects (ants, wasps, bees, termites) and highlight two areas related to premating sexual selection (sexual dimorphism and male mate number) that have remained understudied and in which considerable progress can be achieved with relatively simple approaches. We also infer that mating plugs may be relatively common, and we review further possibilities for postmating sexual selection, which gradually become less likely in termite evolution, but for which eusocial Hymenoptera provide unusual opportunities because they have clonal ejaculates and store viable sperm for up to several decades.
Collapse
Affiliation(s)
- Jacobus J Boomsma
- Institute of Biology, Department of Population Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark.
| | | | | |
Collapse
|
48
|
|
49
|
|
50
|
|