Skip to main content
NCBI home page
Medline Book to support NIHPA logoLink to Medline Book to support NIHPA
. 2022;2450:121–133. doi: 10.1007/978-1-0716-2172-1_6

Studying Placozoa WBR in the Simplest Metazoan Animal, Trichoplax adhaerens.

Hans-Jürgen Osigus, Michael Eitel, Karolin Horn, Kai Kamm, Jennifer Kosubek-Langer, Moritz Jonathan Schmidt, Heike Hadrys, Bernd Schierwater
PMCID: PMC9761494  PMID: 35359305

Abstract

Placozoans are a promising model system to study fundamental regeneration processes in a morphologically and genetically very simple animal. We here provide a brief introduction to the enigmatic Placozoa and summarize the state of the art of animal handling and experimental manipulation possibilities.

Full text of this article can be found in Bookshelf.

References

  1. Grell KG (1971) Trichoplax adhaerens F.E. Schulze und die Entstehung der Metazoan. Naturwissenschaftliche Rundschau 24(4):160–161
  2. Schulze FE (1883) Trichoplax adhaerens, nov. gen., nov. spec. Zool Anz 6:92–97
  3. Schulze FE (1891) Über Trichoplax adhaerens. In: Reimer G (ed) Abhandlungen der Königlichen Preuss. Verlag der königlichen Akademie der Wissenschaften, Berlin, Akademie der Wissenschaften zu Berlin, pp 1–23
  4. Schierwater B (2005) My favorite animal, Trichoplax adhaerens. BioEssays 27(12):1294–1302. https://doi.org/10.1002/bies.20320 doi: 10.1002/bies.20320. [DOI] [PubMed]
  5. Schierwater B, DeSalle R (2018) Placozoa. Curr Biol 28(3):R97–R98. https://doi.org/10.1016/j.cub.2017.11.042 doi: 10.1016/j.cub.2017.11.042. [DOI] [PubMed]
  6. Osigus HJ, Rolfes S, Herzog R, Kamm K, Schierwater B (2019) Polyplacotoma mediterranea is a new ramified placozoan species. Curr Biol 29(5):R148–R149. https://doi.org/10.1016/j.cub.2019.01.068 doi: 10.1016/j.cub.2019.01.068. [DOI] [PubMed]
  7. Eitel M, Francis WR, Varoqueaux F, Daraspe J, Osigus HJ, Krebs S, Vargas S, Blum H, Williams GA, Schierwater B, Worheide G (2018) Comparative genomics and the nature of placozoan species. PLoS Biol 16(7):e2005359. https://doi.org/10.1371/journal.pbio.2005359 doi: 10.1371/journal.pbio.2005359. [DOI] [PMC free article] [PubMed]
  8. Schierwater B (2013) Placozoa, Plattentiere. In: Westheide W, Rieger R (eds) Spezielle Zoologie. Teil 1: Einzeller und Wirbellose Tiere. 3rd edn. Springer Spektrum Berlin pp. 103–107
  9. Schierwater B, Eitel M, Osigus HJ, von der Chevallerie K, Bergmann T, Hadrys H et al (2010) Trichoplax and Placozoa: one of the crucial keys to understanding metazoan evolution. In: DeSalle R, Schierwater B (eds) Key transitions in animal evolution. CRC Press, Boca Raton, FL, pp 289–326
  10. Schierwater B, Eitel M (2015) Placozoa. In: Wanninger A (ed) Evolutionary developmental biology of invertebrates 1: introduction, non-Bilateria, Acoelomorpha, Xenoturbellida. Chaetognatha. Springer Vienna, Vienna, pp 107–114. https://doi.org/10.1007/978-3-7091-1862-7_5 doi: 10.1007/978-3-7091-1862-7_5. [DOI]
  11. Smith CL, Varoqueaux F, Kittelmann M, Azzam RN, Cooper B, Winters CA, Eitel M, Fasshauer D, Reese TS (2014) Novel cell types, neurosecretory cells, and body plan of the early-diverging metazoan Trichoplax adhaerens. Curr Biol 24(14):1565–1572. https://doi.org/10.1016/j.cub.2014.05.046 doi: 10.1016/j.cub.2014.05.046. [DOI] [PMC free article] [PubMed]
  12. Mayorova TD, Hammar K, Winters CA, Reese TS, Smith CL (2019) The ventral epithelium of Trichoplax adhaerens deploys in distinct patterns cells that secrete digestive enzymes, mucus or diverse neuropeptides. Biol Open 8(8):bio045674. https://doi.org/10.1242/bio.045674 doi: 10.1242/bio.045674. [DOI] [PMC free article] [PubMed]
  13. Romanova DY, Varoqueaux F, Daraspe J, Nikitin MA, Eitel M, Fasshauer D, Moroz LL (2021) Hidden cell diversity in Placozoa: ultrastructural insights from Hoilungia hongkongensis. Cell Tissue Res 385(3):623–637. https://doi.org/10.1007/s00441-021-03459-y doi: 10.1007/s00441-021-03459-y. [DOI] [PMC free article] [PubMed]
  14. Sebe-Pedros A, Chomsky E, Pang K, Lara-Astiaso D, Gaiti F, Mukamel Z, Amit I, Hejnol A, Degnan BM, Tanay A (2018) Early metazoan cell type diversity and the evolution of multicellular gene regulation. Nat Ecol Evol 2(7):1176–1188. https://doi.org/10.1038/s41559-018-0575-6 doi: 10.1038/s41559-018-0575-6. [DOI] [PMC free article] [PubMed]
  15. Jakob W, Sagasser S, Dellaporta S, Holland P, Kuhn K, Schierwater B (2004) The Trox-2 Hox/ParaHox gene of Trichoplax (Placozoa) marks an epithelial boundary. Dev Genes Evol 214(4):170–175. https://doi.org/10.1007/s00427-004-0390-8 doi: 10.1007/s00427-004-0390-8. [DOI] [PubMed]
  16. Schierwater B, de Jong D, Desalle R (2009) Placozoa and the evolution of Metazoa and intrasomatic cell differentiation. Int J Biochem Cell Biol 41(2):370–379. https://doi.org/10.1016/j.biocel.2008.09.023 doi: 10.1016/j.biocel.2008.09.023. [DOI] [PubMed]
  17. Grell KG, Benwitz G (1971) Die Ultrastruktur von Trichoplax adhaerens F.E. Schulze. Cytobiologie 4:216–240
  18. Jackson AM, Buss LW (2009) Shiny spheres of placozoans (Trichoplax) function in anti-predator defense. Invertebr Biol 128(3):205–212. https://doi.org/10.1111/j.1744-7410.2009.00177.x doi: 10.1111/j.1744-7410.2009.00177.x. [DOI]
  19. Mayorova TD, Smith CL, Hammar K, Winters CA, Pivovarova NB, Aronova MA, Leapman RD, Reese TS (2018) Cells containing aragonite crystals mediate responses to gravity in Trichoplax adhaerens (Placozoa), an animal lacking neurons and synapses. PLoS One 13(1):e0190905. https://doi.org/10.1371/journal.pone.0190905 doi: 10.1371/journal.pone.0190905. [DOI] [PMC free article] [PubMed]
  20. Romanova DY, Heyland A, Sohn D, Kohn AB, Fasshauer D, Varoqueaux F, Moroz LL (2020) Glycine as a signaling molecule and chemoattractant in Trichoplax (Placozoa): insights into the early evolution of neurotransmitters. Neuroreport 31(6):490–497. https://doi.org/10.1097/WNR.0000000000001436 doi: 10.1097/WNR.0000000000001436. [DOI] [PubMed]
  21. Ueda T, Koya S, Maruyama YK (1999) Dynamic patterns in the locomotion and feeding behaviors by the placozoan Trichoplax adhaerence. Biosystems 54(1–2):65–70 doi: 10.1016/s0303-2647(99)00066-0. [DOI] [PubMed]
  22. Fortunato A, Aktipis A (2019) Social feeding behavior of Trichoplax adhaerens. Front Ecol Evol 7:19. https://doi.org/10.3389/fevo.2019.00019 doi: 10.3389/fevo.2019.00019. [DOI] [PMC free article] [PubMed]
  23. Smith CL, Pivovarova N, Reese TS (2015) Coordinated feeding behavior in Trichoplax, an animal without synapses. PLoS One 10(9):e0136098. https://doi.org/10.1371/journal.pone.0136098 doi: 10.1371/journal.pone.0136098. [DOI] [PMC free article] [PubMed]
  24. Smith CL, Reese TS, Govezensky T, Barrio RA (2019) Coherent directed movement toward food modeled in Trichoplax, a ciliated animal lacking a nervous system. Proc Natl Acad Sci U S A 116(18):8901–8908. https://doi.org/10.1073/pnas.1815655116 doi: 10.1073/pnas.1815655116. [DOI] [PMC free article] [PubMed]
  25. Heyland A, Croll R, Goodall S, Kranyak J, Wyeth R (2014) Trichoplax adhaerens, an enigmatic basal metazoan with potential. Methods Mol Biol 1128:45–61. https://doi.org/10.1007/978-1-62703-974-1_4 doi: 10.1007/978-1-62703-974-1_4. [DOI] [PubMed]
  26. Schwartz V (1984) The radial polar pattern of differentiation in Trichoplax adhaerens F.E. Schulze (Placozoa). Z. Naturforsch. C 39:818–832
  27. Zuccolotto-Arellano J, Cuervo-Gonzalez R (2020) Binary fission in Trichoplax is orthogonal to the subsequent division plane. Mech Dev 162:103608. https://doi.org/10.1016/j.mod.2020.103608 doi: 10.1016/j.mod.2020.103608. [DOI] [PubMed]
  28. Ruthmann A, Terwelp U (1979) Disaggregation and reaggregation of cells of the primitive metazoan Trichoplax adhaerens. Differentiation 13:185–198
  29. Miller RL (1971) Observations on Trichoplax Adhaerens Schulze, 1883. Am Zool 11(4):698–699
  30. Kuhl W, Kuhl G (1963) Bewegungsphysiologische Untersuchungen an Trichoplax adhaerens F. E. Schulze. Zoologischer Anzeiger Suppl 26:460–469
  31. Kuhl W, Kuhl G (1966) Untersuchungen über das Bewegungsverhalten von Trichoplax adhaerens F.E.Schulze. Z Morphol Oekol Tiere 56:417–435
  32. Eitel M, Schierwater B (2010) The phylogeography of the Placozoa suggests a taxon-rich phylum in tropical and subtropical waters. Mol Ecol 19(11):2315–2327. https://doi.org/10.1111/j.1365-294X.2010.04617.x doi: 10.1111/j.1365-294X.2010.04617.x. [DOI] [PubMed]
  33. von der Chevallerie K (2013) Experimental studies on the tumor suppressor p53, the myc protooncogene and tissue compatibility in the basal metazoan phylum Placozoa. PhD Thesis
  34. Rassat J, Ruthmann A (1979) Trichoplax adhaerens F. E. Schulze (Placozoa) in the scanning electron microscope. Zoomorphology 93:59–72
  35. DuBuc TQ, Ryan JF, Martindale MQ (2019) "dorsal-ventral" genes are part of an ancient axial patterning system: evidence from Trichoplax adhaerens (Placozoa). Mol Biol Evol 36(5):966–973. https://doi.org/10.1093/molbev/msz025 doi: 10.1093/molbev/msz025. [DOI] [PMC free article] [PubMed]
  36. Prakash VN, Bull MS, Prakash M (2021) Motility-induced fracture reveals a ductile-to-brittle crossover in a simple animal's epithelia. Nat Phys 17(4):504. https://doi.org/10.1038/s41567-020-01134-7 doi: 10.1038/s41567-020-01134-7. [DOI]
  37. Artificial Seawater (2012). Cold Spring Harbor protocols 2012 (2):pdb.rec068270. https://doi.org/10.1101/pdb.rec068270 doi: 10.1101/pdb.rec068270. [DOI]
  38. Calcium- and magnesium-free artificial seawater (CMF-ASW) (2009). Cold Spring Harbor Protocols 2009 (12):pdb.rec12053. https://doi.org/10.1101/pdb.rec12053 doi: 10.1101/pdb.rec12053. [DOI]
  39. Miyazawa H, Nakano H (2018) Multiple surveys employing a new sample-processing protocol reveal the genetic diversity of placozoans in Japan. Ecol Evol 8(5):2407–2417. https://doi.org/10.1002/ece3.3861 doi: 10.1002/ece3.3861. [DOI] [PMC free article] [PubMed]
  40. Schierwater B, Kamm K, Wysocki K, Osigus HJ (2021) Phylum Placozoa. In: Schierwater B, DeSalle R (eds) Invertebrate zoology: a tree of life approach. Taylor & Francis, Abingdon-on-Thames, Oxfordshire

RESOURCES