Cilia pp 245-254 | Cite as

Planaria as a Model System for the Analysis of Ciliary Assembly and Motility

  • Stephen M. KingEmail author
  • Ramila S. Patel-King
Part of the Methods in Molecular Biology book series (MIMB, volume 1454)


Planarian flatworms are carnivorous invertebrates with astounding regenerative properties. They have a ventral surface on which thousands of motile cilia are exposed to the extracellular environment. These beat in a synchronized manner against secreted mucus thereby propelling the animal forward. Similar to the nematode Caenorhabditis elegans, the planarian Schmidtea mediterranea is easy to maintain in the laboratory and is highly amenable to simple RNAi approaches through feeding with dsRNA. The methods are simple and robust, and the level of gene expression reduction that can be obtained is, in many cases, almost total. Moreover, cilia assembly and function is not essential for viability in this organism, as animals readily survive for weeks even with the apparent total absence of this organelle. Both genome and expressed sequence tag databases are available and allow design of vectors to target any desired gene of choice. Combined, these feature make planaria a useful model system in which to examine ciliary assembly and motility, especially in the context of a ciliated epithelium where many organelles beat in a hydrodynamically coupled synchronized manner. In addition, as planaria secrete mucus against which the cilia beat to generate propulsive force, this system may also prove useful for analysis of mucociliary interactions. In this chapter, we provide simple methods to maintain a planarian colony, knockdown gene expression by RNAi, and analyze the resulting animals for whole organism motility as well as ciliary architecture and function.

Key words

Axoneme Cilia Dynein Microtubule Planaria 



Our laboratory is supported by grant GM051293 (to S.M.K.) from the National Institutes of Health.


  1. 1.
    Mitchell DR (2007) The evolution of eukaryotic cilia and flagella as motile and sensory organelles. Adv Exp Med Biol 607:130–140CrossRefPubMedCentralGoogle Scholar
  2. 2.
    King SM, Pazour GJ (2009) Cilia: model organisms and intraflagellar transport. Methods in cell biology, vol 93. Elsevier, Burlington, MAGoogle Scholar
  3. 3.
    Witman GB (1986) Isolation of Chlamydomonas flagella and flagellar axonemes. Methods Enzymol 134:280–290CrossRefGoogle Scholar
  4. 4.
    Sears PR, Davis CW, Chua M, Sheehan JK (2011) Mucociliary interactions and mucus dynamics in ciliated human bronchial epithelial cell cultures. Am J Physiol 301:L181–L186CrossRefGoogle Scholar
  5. 5.
    Sawamoto K, Wichterle H, Gonzalez-Perez O, Cholfin JA, Yamada M, Spassky N, Murcia NS, Garcia-Verdugo JM, Marin O, Rubenstein JLR, Tessier-Lavigne M, Okano H, Alvarez-Buylla A (2006) New neurons follow the flow of cerebrospinal fluid in the adult brain. Science 311:629–632CrossRefGoogle Scholar
  6. 6.
    Rink JC (2013) Stem cell systems and regeneration in planaria. Dev Gene Evol 223:67–84CrossRefGoogle Scholar
  7. 7.
    Newmark P, Sanchez-Alvarado A (2002) Not your father's planarian: a classic model enters the era of functional genomics. Nat Rev Genet 3:210–219CrossRefGoogle Scholar
  8. 8.
    Rompolas P, King SM (2009) Schmidtea mediterranea: a model system for analysis of motile cilia. Methods Cell Biol 93:81–98CrossRefGoogle Scholar
  9. 9.
    Azimzadeh J, Wong ML, Downhour DM, Sanchez-Alvarado A, Marshall WF (2012) Centrosome loss in the evolution of planarians. Science 335:461–463CrossRefPubMedCentralGoogle Scholar
  10. 10.
    Rink J, Gurley K, Eliot S, Sanchez-Alvarado A (2008) Planarian Hh signaling regulates regeneration polarity and links Hh pathway evolution to cilia. Science 326:1406–1410CrossRefGoogle Scholar
  11. 11.
    Almuedo-Castillo M, Salo E, Adell T (2011) Dishevelled is essential for neural connectivity and planar cell polarity in planarians. Proc Natl Acad Sci U S A 108:2813–2818CrossRefPubMedCentralGoogle Scholar
  12. 12.
    Rompolas P, Patel-King RS, King SM (2010) An outer arm dynein conformational switch is required for metachronal synchrony of motile cilia in Planaria. Mol Biol Cell 21:3669–3679CrossRefPubMedCentralGoogle Scholar
  13. 13.
    Newmark P, Reddien P, Cebria F, Sanchez-Alvarado A (2003) Ingestion of bacterially expressed double-stranded RNA inhibits gene expression in planaria. Proc Natl Acad Sci U S A 100:11861–11865CrossRefPubMedCentralGoogle Scholar
  14. 14.
    Dawar B (1973) A combined relaxing agent and fixative for Triclads (Planarians). Biotech Histochem 48:93–94Google Scholar
  15. 15.
    Patel-King RS, Gilberti RM, Hom EFY, King SM (2013) WD60/FAP163 is a dynein intermediate chain required for retrograde intraflagellar transport in cilia. Mol Biol Cell 24:2668–2677CrossRefPubMedCentralGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  1. 1.Department of Molecular Biology and BiophysicsUniversity of Connecticut Health CenterFarmingtonUSA
  2. 2.Institute for Systems GenomicsUniversity of Connecticut Health CenterFarmingtonUSA

Personalised recommendations