The Motile Behavior of Amoebae in the Aggregation Wave in Dictyostelium Discoideum
Pattern develops during the aggregation process in the cellular slime mold Dictyostelium discoideum, and although aggregation appears to represent a more dynamic process than the genesis of a more static morphogenetic field, it shares several of the same basic characteristics. As hypothesized for some forms of positional information (Wolpert 1971), aggregation information is in the form of a signal emanating from a source and in this case is amplified through a relay system between cells. Cells respond individually to the signal with directional movement towards the source (Alcantara & Monk 1974), which is the aggregation center. Because of the ease of experimental manipulation, gene cloning, and targeted mutagenesis, the process of signal genesis, signal transduction, and the motile response in D. discoideum is rapidly being elucidated and warrants careful scrutiny by researchers in the field of pattern formation. In this mini-review, we will focus on the behavioral response of cells to the naturally propagated cAMP wave. We will consider a wave paradox which has been explained by a temporal mechanism for Chemotaxis (Varnum et al. 1985; Soll 1990), and then describe methods for assessing the role of particular cytoskeletal elements in the motile response to the natural wave.
KeywordsDepression Agar Recombination Mold Phospho
Unable to display preview. Download preview PDF.
- Fisher, P., Merkl, R., & Gerisch, G. 1989. Quantitative analysis of cell motility and Chemotaxis in Dictyostelium. J. Cell Biol., 92, 807–821.Google Scholar
- Loomis, W. F. 1982. The Development of Dictyostelium discoideum. New York: Academic Press.Google Scholar
- Newell, P. C., & Europe-Finner, G. N. 1990. Signal transduction for Chemotaxis in Dictyostelium amoebae. Sem. Cell Biol., 1(2), 105–114.Google Scholar
- Shaffer, B. M. 1957. Aspects of aggregation in the cellular slime molds. 1. orientation and Chemotaxis. Nature, 91, 19–35.Google Scholar
- Soll, D. R., Voss, E., & Wessels, D. 1987. Development and application of the “Dynamic Morphology System” for the analysis of moving amoebae. Proc. SPIE, 832, 821–830.Google Scholar
- Soll, D. R., Vawter-Hugart, H., & Voss, E. 1993. “3D-DIAS”: A computer-assisted method for quantitating the three-dimensional motion parameters of motile cells. (In preparation).Google Scholar
- Sylwester, A. W., Wessels, D., & Soll, D. R. 1992. Myosin-IA cells among aggregating wild-type cells exhibit aberrant chemotactic behaviors. (In preparation).Google Scholar
- Titus, M., Wessels, D., Spudich, J., & Soll, D. R. 1992. The unconventional myosin encoded by the myoA gene plays a role in Dictyostelium motility.Molec. Biol Cell. (In press).Google Scholar
- Varnum-Finney, B., Edwards, K., Voss, E., & Soll, D. 1987a. Amoebae of Dictyostelium discoideum respond to an increasing temporal gradient of the chemoattractant cAMP with a reduced frequency of turning: evidence for a temporal mechanism in ameboid Chemotaxis. Cell Motil. Cytoskel, 8, 7–17.CrossRefGoogle Scholar
- Wessels, D., Murray, J., Sylwester, A., Vawter-Hugart, H., & Soll, D. R. 1993. The three dimensional dynamics of pseudopod formation and turning during the motility cycle of Dictyostelium. (Submitted).Google Scholar