How well can an amoeba climb? -- Data Supplement - Supplemental Movies -- Proceedings of the National Academy of Sciences

Supplementary material for Fukui et al. (2000) Proc. Natl. Acad. Sci. USA 97 (18), 10020-10025.

QuickTime Video Movie1.
A myosin II (conventional myosin) knockout mutant of Dictyostelium discoideum (HS1) aggregating under a Centrifuge Polarizing Microscope (CPM) rotating at 11,700 rpm (ca. 10,500 ´ g). This mutant can generate only 25% of migration forces of the wild-type amoeba (i.e., 250 pN) and unable to migrate "upward" under this centrifugal field. However, the cells maintain adhesion to the substrate and exhibit aggregation behavior by cAMP-mediated chemotaxis. Because of biased migration vector, the aggregation stream becomes V-shaped and the aggregation center is gradually pushed downward. This is caused by the downward thrust of migration forces in individual amoeba. DIC ´20. Total 6 min in real time.