The Hydra Holobiont: A Tale of Several Symbiotic Lineages

  • Thomas C. G. Bosch
  • David J. Miller


The personal journey of one of us (TB) toward the realization that beneficial microbes are important began in summer 2000 when Jens Schröder, a dermatologist at Kiel University, on the occasion of the inauguration of the new chair of Zoology asked if Hydra were not a good model system to investigate the biochemistry of epithelial defenses. Nobody at that time would have anticipated that this triggered the development of a novel model system in comparative and evolutionary immunology. Up to that moment, Hydra was all for examining developmental mechanisms in an evolutionary context and to uncover basic principles of pattern formation and stem cell regulation. To think of immune reactions as equally important features of an animal did not come to our mind. That evolution of a simple multicellular animal such as Hydra means both invention of developmental pathways to shape and maintain a given body plan and also to protect this body all life long, and understanding that part of that context requires understanding the biotic and abiotic environment in which Hydra evolved turned out to be enlightening and exciting. This chapter will show just how much we know about host–microbe interactions in Hydra and what these findings mean in a more general context of holobiont research.


Bacterial Community Antimicrobial Peptide Nurse Cell Symbiotic Alga Interspecies Interaction 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Becker T, Loch G, Beyer M, Zinke I, Aschenbrenner AC, Carrera P, Inhester T, Schultze JL, Hoch M (2010) FOXO-dependent regulation of innate immune homeostasis. Nature 463(7279):369–373Google Scholar
  2. Boehm AM, Rosenstiel P, Bosch TCG (2013) Stem cells and aging from a quasi-immortal point of view. Bioessays 35(11):994–1003CrossRefPubMedGoogle Scholar
  3. Boehm AM, Hemmrich G, Khalturin K, Puchert M, Anton-Erxleben F, Wittlieb J, Klostermeier UC, Rosenstiel P, Oberg H-H, Bosch TCG (2012) FoxO is a critical regulator of stem cell maintenance and immortality in Hydra. Proc Natl Acad Sci U S A 109(48):19697–19702CrossRefPubMedPubMedCentralGoogle Scholar
  4. Bosch TCG (2012) What Hydra has to say about the role and origin of symbiotic interactions. Biol Bull 223:78–84PubMedGoogle Scholar
  5. Bosch TCG (2013) Cnidarian-microbe interactions and the origin of innate immunity in metazoans. Ann Rev Microbiol 67:499–518CrossRefGoogle Scholar
  6. Bosch, TCG, Augustin R, Anton-Erxleben F, Fraune S, Hemmrich G, Zill H, Rosenstiel P, Jacobs G, Schreiber S, Leippe M, Stanisak M, Grotzinger, Jung S, Podschun R, Bartels J, Harder J, Schroder JM (2009) Uncovering the evolutionary history of innate immunity: the simple metazoan Hydra uses epithelial cells for host defence. Developmental and comparative immunology 33:559–569Google Scholar
  7. Chapman JA, Kirkness EF, Simakov O, Hampson SE, Mitros T, Weinmaier T, Rattei T, Balasubramanian PG, Borman J, Busam D, Disbennett K, Pfannkoch C, Sumin N, Sutton GG, Viswanathan LD, Walenz B, Goodstein DM, Hellsten U, Kawashima T, Prochnik SE, Putnam NH, Shu S, Blumberg B, Dana CE, Gee L, Kibler DF, Law L, Lindgens D, Martinez DE, Peng J, Wigge PA, Bertulat B, Guder C, Nakamura Y, Ozbek S, Watanabe H, Khalturin K, Hemmrich G, Franke A, Augustin R, Fraune S, Hayakawa E, Hayakawa S, Hirose M, Hwang JS, Ikeo K, Nishimiya-Fujisawa C, Ogura A, Takahashi T, Steinmetz PR, Zhang X, Aufschnaiter R, Eder MK, Gorny AK, Salvenmoser W, Heimberg AM, Wheeler BM, Peterson KJ, Böttger A, Tischler P, Wolf A, Gojobori T, Remington KA, Strausberg RL, Venter JC, Technau U, Hobmayer B, Bosch TC, Holstein TW, Fujisawa T, Bode HR, David CN, Rokhsar DS, Steele RE et al (2010) The dynamic genome of Hydra. Nature 464(7288):592–596CrossRefPubMedPubMedCentralGoogle Scholar
  8. Franzenburg S, Fraune S, Altrock PM, Künzel S, Baines JF, Traulsen A, Bosch TCG (2013) Bacterial colonization of Hydra hatchlings follows a robust temporal pattern. ISME J 7(4):781–790CrossRefPubMedPubMedCentralGoogle Scholar
  9. Fraune S, Augustin R, Bosch TCG (2009) Exploring host-microbe interactions in hydra. Microbe 4(10):457–462Google Scholar
  10. Fraune S, Franzenburg S, Augustin R, Bosch TCG (2011a) Das Prinzip Metaorganismus. BIOspektrum 17(6):634–636CrossRefGoogle Scholar
  11. Fraune S, Augustin R, Bosch TCG (2011b) Embryo protection in contemporary immunology: why bacteria matter. Commun Integr Biol 4:369–372CrossRefPubMedPubMedCentralGoogle Scholar
  12. Fraune S, Anton-Erxleben F, Augustin R, Franzenburg S, Knop M, Schröder K, Willoweit-Ohl D, Bosch TCG (2014) Bacteria-bacteria interactions within the microbiota of the ancestral metazoan Hydra contribute to fungal resistance. ISME J 9(7):1543–1556. doi: 10.1038/ismej.2014.239 CrossRefPubMedGoogle Scholar
  13. Habetha M, Anton-Erxleben F, Neumann K, Bosch TCG (2003) The Hydra viridis/Chlorella symbiosis. (I) Growth and sexual differentiation in polyps without symbionts. Zoology 106(2):101–108CrossRefPubMedGoogle Scholar
  14. Habetha M, Bosch TCG (2005) Symbiotic Hydra express a plant-like peroxidase gene during oogenesis. J Exp Biol 208:2157–2164CrossRefPubMedGoogle Scholar
  15. Nebel A, Bosch TCG (2012) Evolution of human longevity: lessons from Hydra (Editorial). Aging 4(11):730–731Google Scholar
  16. Rahat M (1985) Competition between chlorellae in chimeric infections of Hydra viridis: the evolution of a stable symbiosis. J Cell Sci 77:87–92PubMedGoogle Scholar
  17. Rahat M, Reich V (1983) A comparative study of tentacle regeneration and number in symbiotic and aposymbiotic Hydra viridis: effect of Zoochlorellae. J Exp Zool 227:63–68CrossRefGoogle Scholar
  18. Rahat M, Reich V (1984) Intracellular infection of aposymbiotic Hydra viridis by a foreign free-living Chlorella sp.: initiation of a stable symbiosis. J Cell Sci 65:265–277PubMedGoogle Scholar
  19. Thorington G, Margulis L (1981) Hydra viridis: transfer of metabolites between Hydra and symbiotic algae. Biol Bull 160:175–188CrossRefPubMedGoogle Scholar
  20. Trembley A (1744) Mémoires, Pour Servir à l´Histoire d´un Genre de Polypes d´Eau Douce, à Bras en Frome de Cornes. Verbeek, LeidenGoogle Scholar
  21. Wittlieb J, Khalturin K, Lohmann JU, Anton-Erxleben F, Bosch TCG (2006) Transgenic Hydra allow in vivo tracking of individual stem cells during morphogenesis. Proc Natl Acad Sci U S A 103(16):6208–6211CrossRefPubMedPubMedCentralGoogle Scholar

Copyright information

© Springer-Verlag Wien 2016

Authors and Affiliations

  • Thomas C. G. Bosch
    • 1
  • David J. Miller
    • 2
  1. 1.Zoological InstituteChristian Albrechts Universitätzu KielKielGermany
  2. 2.ARC Cnt. of Execl. for Coral Reef Stud.James Cook UniversityTownsvilleAustralia

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