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Thread: Symbionts

  1. #21
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    Default Re: Symbionts

    You mean do they mask out the impact that other factors might have on the health and productivity of a hive?

    I would have to do a survey on that.

  2. #22
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    Default Re: Symbionts

    Well, if you look at it as being a question of what factors are at play and the results of their presence, and assume that the function of treatments is to neutralize some specific sets of them, and also have collateral effects on others, then it would follow that by adding and removing each mask over the data matrix, that some patterns might appear.

  3. #23
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    Default Re: Symbionts

    ergo, hippo fatso...

    treatments might mask out the effects of symbionts on the health and productivity of hives.

    But...

    You still have to design a study to demonstrate that. You know... show significance (that it's not random), test hypotheses.

  4. #24
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    Default Re: Symbionts

    I had thought that the various treatments might turn on an off the symbionts. (As yet unidentified and categorized) and if there is a data collection with appropriate categories that some patterns might emerge and then the causes could be investigated.

    This discussion seems to be getting more and more vague. Some people are going to do something fairly specific. Others question whether it matters and is the best course of action.

  5. #25
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    Default Re: Symbionts

    Allen:

    There are different experimental designs to consider.

    For instance, you can see if any symbionts are eliminated by the treatment while measuring for health/productivity. You can target the symbionts and compare results while using other treatments. You can also use more than one factor as in the contingency table (2x2) design...

    That being said, when you really don't have alot of resources available to you, it's often best to come up with something that's 'elegant'.

    How do you know that a research design is elegant? It's usually somehow related to an historical experiment that was known to be 'elegant'.

  6. #26
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    Default Re: Symbionts

    Elegant is not necessarily complicated. For example, catching mice with a hammer is not elegant. But the original mouse trap which has not really been improved upon is an elegant design. Simple, fulfills its purpose, conceptually easy to understand. That's why nobody has been able to build a better mousetrap.

    Although, you might consider the Havahart type to be better, since it doesn't kill the mouse. But that simply creates another problem of what to do with it.

    An elegant study most definitely will "trap" the information you are looking for in an unambiguous way. That is why so much thought goes into the preparation of studies, or surveys, or animal traps. You have to really KNOW your subject, and your objective.

    If trapping the mouse alive is the objective, the first two methods are complete failures; only the Havahart trap succeeds on that count.

  7. #27
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    Default Re: Symbionts

    Back to symbionts:

    > The health of animals, including humans, is dependent on their resident microbiota, but the complexity of the microbial communities makes these associations difficult to study in most animals. Exceptionally, the microbiology of the pea aphid Acyrthosiphon pisum is dominated by a single bacterium Buchnera aphidicola (B. aphidicola). A 1H NMR-based metabonomic strategy was applied to investigate metabolic profiles of aphids fed on a low essential amino acid diet and treated by antibiotic to eliminate B. aphidicola. In addition, differential gel electrophoresis (DIGE) with mass spectrometry was utilized to determine the alterations of proteins induced by these treatments. We found that these perturbations resulted in significant changes to the abundance of 15 metabolites and 238 proteins.

    Integrated Metabonomic-Proteomic Analysis of an Insect-Bacterial Symbiotic System -- Journal of Proteome Research

  8. #28
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    Default Re: Symbionts

    > Parallel metabonomic and proteomic analysis has provided an excellent demonstration of the central role of amino acid metabolism in the aphid symbiosis with B. aphidicola and identified several key proteins and processes (e.g., CTLD protein, regucalcin) with candidate role in the function and persistence of the symbiosis. These have potential as targets for novel insect pest control strategies. More generally, this investigation of an insect association with a single microbial taxon demonstrates the value of combined proteomic and metabonomic analysis for the study of interactions between animals and their resident microbiota.

    -- ibid

  9. #29
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    Default Re: Symbionts

    Not all gut symbionts are beneficial to the host: Wasp carries son-killing bacteria in gut

    Four percent of female Nasonia vitripennis carry the son-killer bacterium Arsenophonus nasoniae, a microbe with notably different biology from other inherited parasites and symbionts.

    Galan & Bliska (1996) described the relationship between bacteria and host as a complex cross talk.

    Arsenophonus nasoniae first attracted attention because of its son-killer phenotype, and this paper is the first to describe potential virulence components of a malekilling bacterium. However, the biochemical mechanism by which A. nasoniae induces its killing of male offspring remains elusive.

    The availability of both the host genome (Werren et al., 2010) and that of A. nasoniae provides new avenues for functional investigation of both host invasion and mechanisms of male-killing.
    The draft genome sequence of Arsenophonus nasoniae, son-killer bacterium of Nasonia vitripennis, reveals genes associated with virulence and symbiosis -- Insect Molecular Biology (2010)

  10. #30
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    Default Re: Symbionts

    Quote Originally Posted by peterloringborst View Post
    Not all gut symbionts are beneficial to the host: Wasp carries son-killing bacteria in gut)
    i don't have access to this paper, but in this particular case, i expect there are some "benefits" based on:

    1. the title of the paper, which includes, "reveals genes associated with virulence and symbiosis"

    2. the text from the abstract that peter pasted includes, "notably different biology from other inherited parasites and symbionts."

    in both cases, the inclusion of the word "symbiont" and "symbiosis" indicate that this is a mutually beneficial relationship, at least in some regards.

    i think that if they were not beneficial, the authors would have described the bacteria as a disease/infection or perhaps a parasite. for instance, do we consider nosema a symbiont?

    deknow

  11. #31
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    Default Re: Symbionts

    The definition of symbiosis is in flux, and the term has been applied to a wide range of biological interactions. The symbiotic relationship may be categorized as mutualistic, commensal, or parasitic in nature. Others define it more narrowly, as only those relationships from which both organisms benefit, in which case it would be synonymous with mutualism.

    Symbiotic relationships include those associations in which one organism lives on another (ectosymbiosis, such as mistletoe), or where one partner lives inside the other (endosymbiosis, such as lactobacilli and other bacteria in humans or zooxanthelles in corals).

    Symbiotic relationships may be either obligate, i.e., necessary for the survival of at least one of the organisms involved, or facultative, where the relationship is beneficial but not essential for survival of the organisms.

    A parasitic relationship is one in which one member of the association benefits while the other is harmed. Parasitic symbioses take many forms, from endoparasites that live within the host's body to ectoparasites that live on its surface. In addition, parasites may be necrotrophic, which is to say they kill their host, or biotrophic, meaning they rely on their host's surviving.

  12. #32
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    Default Re: Symbionts

    Quote Originally Posted by Allen Dick View Post
    > Some beekeepers are adding probiotics to the feeding constituent of bees to improve their health.

    I've heard that, too. It seems like a good idea -- perhaps, but wonder: What specific organisms? And how is it known that this is beneficial?

    After all, without any evidence, the practice could as easily be harmful, or useless.
    My thoughts exacly. The most common pro-biotics taken by humans (and sold in health food stores) are various species of lactobacilli. The post above yours quoting the Slovakian study of bees gut fauna didn't find any lactobacilli in the bees...

    I guess you could wipe out most of the gut fauna with antibiotics then reintroduce various bacteria in combination and see what happens to the colony health. To do it right it would be an involved study that would last years.

  13. #33
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    Default Re: Symbionts

    I submit that if using antibiotics is a bad idea (I'm not saying it is) the same would apply to so called probiotics. We have no clear idea on what the gut flora of bees is supposed to look like, but it appears not to be seriously affected by TM. Now tylosin may be another matter. Clearly the affect of antibiotics on bees is a subject rife with speculation. Without any clear evidence I would not go dumping MORE things into hives. Especially bacteria. It's illegal anyway. Only a few things are really approved for in hive use. Some of them shouldn't be, I know, but I would stick to approved and safe. Avoid unapproved and/or unsafe.

  14. #34
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    Default Re: Symbionts

    The microbiota associated to the honey bee Apis mellifera mellifera L. is complex and far from being fully understood, or even known.

    The scientific works where the presence of lactic acid bacteria associated to honey bee-gut is reported are limited.

    In this work, Lactobacillus and Enterococcus strains were isolated from the gut of the summer adult worker Apis mellifera L.bees of the Argentinean Northwest region.

    Eight strains belonging to Lactobacillus spp. and five to Enterococcus spp. were isolated from the gut of worker Apis mellifera L. bees.

    A high in vitro susceptibility of P.larvae vegetative cells to a low pH, unreported so far for this bacterium, was observed in this work. This is the first report on P. larvae growth inhibition due to acidity generated by lactobacilli isolated from the bee gut ecosystem.
    from "Properties of different lactic acid bacteria isolated from Apis mellifera L. bee-gut" Microbiological Research (in press)
    M. CarinaAudisio

  15. #35
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    Default Re: Symbionts

    ...if true, then the work tobias and alejandra have done must show some mechanism of inhibition other than pH?

    deknow

  16. #36
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    Default Re: Symbionts

    sorry, the thing you posted is in the bee's gut, tobias and alejandra were looking at the bacteria in the honey stomach.

    deknow

  17. #37
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    Default Re: Symbionts

    In this study, effects of the Bt-toxin Cry1Ab and a soybean trypsin inhibitor (SBTI) on intestinal bacterial communities of adult honeybees (Apis mellifera) were investigated. It was hypothesised that changes in intestinal bacterial communities of honeybees may represent a sensitive indicator for altered intestinal physiology.

    Neither Bt-maize pollen nor high concentrations of Cry1Ab significantly affected bacterial communities in honeybee intestines. Only the high concentration of SBTI significantly reduced the number of T-RFs detected in honeybee midguts, a concentration that also increases bee mortality. Therefore, total bacterial community structures may not be a sensitive indicator providing evidence for impact of insecticidal proteins on honeybees already at sub-lethal levels.
    "Bacterial community structures in honeybee intestines and their response to two insecticidal proteins"
    Dirk Babendreier, David Joller, Jörg Romeis, Franz Bigler and Franco Widmer
    Agroscope Reckenholz-Tänikon Research Station ART, Reckenholzstr. 191, 8046 Zürich, Switzerland

  18. #38
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    Default Re: Symbionts

    To date little attention has been paid to the possible contribution of the microflora associated with the pollen grains to the overall allergenic effect of pollen.

    Colldahl and Carlsson demonstrated in 1968 that patients allergic to pollens reacted to specific pollen extracts, as well as to extracts prepared from microorganisms (a fungus Cryptococcus luteolus and a Gram-negative bacterium Pseudomonas maltophilia) cultured from samples of these pollens.

    In the case of Cryptococcus luteolus, the authors supported their clinical observation by results of the Ouchterlony test. Using scanning electron microscopy, Colldahl and Nilsson observed bacteria and fungi on surfaces of pollen grains.

    To the best of our knowledge, no further studies on the possible role of Gram-negative bacteria in pollen allergy were undertaken, and the problem of the potential effects of bacterial endotoxin associated with pollen has never been studied.
    BACTERIAL ENDOTOXIN ASSOCIATED WITH POLLEN AS A POTENTIAL FACTOR AGGRAVATING POLLINOSIS
    Department of Aerobiology and Allergology, Institute of Agricultural Medicine, Lublin, Poland

  19. #39
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    Default Re: Symbionts

    Current theory suggests that mutualisms are best viewed as reciprocal exploitations that nonetheless provide net benefits to each partner. This view stresses the disruptive potential of conflicts of interests among the erstwhile partners. Consequently, identifying factors that influence the costs and benefits to each partner and quantifying their influence constitute primary research objectives. In particular, inquiry centers on the description of conflicts of interest between partners and the attempt to understand what mediates them10.

    Ultimately, we cannot begin to determine whether there are any general principles or consistent patterns that characterize mutualisms if we misunderstand individual case studies. Ideally, for a number of cases, we need to identify and quantify the costs and benefits to each party, and to understand what factors influence variation in those costs and benefits. Importantly, we need to understand conflicts of interest and attempt to identify what factors maintain the alignment of interests. If there is nonalignment, what prevents the system from breaking down? To do this, it is crucial that we identify the mutualists, and understand their diversity, patterns of transmission and structuring at several spatial, temporal and evolutionary scales.
    The evolution of mutualisms: exploring the paths between conflict and cooperation
    E.A. Herre, N. Knowlton, U.G. Mueller and S.A. Rehner
    TREE vol. 14, no. 2 February 1999

  20. #40
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    Default Re: Symbionts

    One of the most distinctive features of many symbiotic and pathogenic genomes, extremely small size, does not appear to be an adaptation for living within hosts but a neutral or even deleterious consequence of long-term evolution under the conditions imposed by these life-styles. One consequence of genome reduction is that specialized symbionts and pathogens are unable to reacquire the multitude of eliminated genes and thus cannot revert to a life-style independent from hosts.

    This irreversibility is supported by the phylogenetic distribution of small-genome organisms, which occur in clades that are uniformly symbiotic or parasitic. Although pathogens and symbionts show clear parallels in their genetic responses to living within hosts, they differ in some aspects of their genome contents. Specialized mutualistic symbionts, often in cooperation with their hosts, are able to circumvent host defenses through mechanisms such as sequestration within specialized host tissues or cells that function as refuges
    Genes Lost and Genes Found: Evolution of Bacterial Pathogenesis and Symbiosis
    Howard Ochman and Nancy A. Moran
    2001 VOL 292 SCIENCE www.sciencemag.org

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