The pattern formation lab deals with spontaneous pattern formation in standing cultures of Tetrahymena. The honeycomb patterns formed in standing cultures of Tetrahymena have been linked to convection, chemotaxis, and cell-cell interaction, making this module not only useful as an independent biology lab but also potentially interesting as a cross platform vehicle for linking biology, math, and physics. Since various conditions affect spontaneous pattern formation and reaggregation, including media, cell density and environmental conditions, the lab lends itself to independent student inquiry and experimental design.

Video
This very short clip shows a pattern forming in real time.
Module Protocols

High School

Relevant Concepts

Science as a Process; Cell – Cell Interaction; Cell Response to Environmental Stimuli

Next Generation Science Standards Relationships

High School

HS-LS1-2 Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms.

HS-LS1-3 Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis. 

HS-LS2-8 Evaluate the evidence for the role of group behavior on individual and species’ chances to survive and reproduce. 

References

●Childress S, Levandowsky M, Spiegel EA. 1975. Pattern formation in a suspension of swimming microorganisms: equations and stability theory. 69 (3):591-613.

●Kage A, Asato E, Chiba Y, Wada Y, Katsu-Kimura Y, Kubota A, Sawai S, Niihori M, Baba SA, Mogami Y. 2011. Gravity-dependent changes in bioconvection of Tetrahymena and Chlamydomonas during parabolic flight: increases in wave number induced by pre- and post-parabola hypergravity. Zoolog Sci. 28 (3):206-214.

●Loefer JB and Mefferd RB. 1952. Concerning Pattern Formation by Free-Swimming Microorganisms. Am.Nat. 86 (830):325-329.

●Mogami Y, Yamane A, Gino A, Baba SA. 2004. Bioconvective pattern formation of Tetrahymena under altered gravity. J.Exp.Biol. 207 (Pt 19):3349-3359.

●Noever DA. 1991. Evolution of bioconvective patterns in variable gravity. Phys.Rev.A. 44 (8):5279-5291.

●Noever DA, Matsos HC, Cronise RJ, Looger LL, Relwani RA, Johnson JU. 1994. Computerized in vitro test for chemical toxicity based on Tetrahymena swimming patterns. Chemosphere 29 (6):1373-1384.

●Noever DA, Cronise R, Matsos HC. 1994. Preferred negative geotactic orientation in mobile cells: Tetrahymena results. Biophys.J. 67 (5):2090-2095.

See our glossary for the terms used in the modules.