McNamara 1987 UIUC PhD Dissertation - Morphogenetic movements contributing to cell aggregation in Dictyostelium discoideum wild-type and streamer F mutants.
PhD Supervisor: Robert P. Futrelle.
We investigated some cell processes which may contribute to cell aggregation patterns in the social ameba Dictyostelium discoideum. Aggregation is known to be mediated by chemotaxis up periodic extracellular cAMP gradients; however, the details of cell movement during this stage of development have not been reported. We recorded cell behavior by time-lapse cinemicroscopy and collected cell motion and cell shape data by computer-aided planimetry.
Bottom line is that I discovered that the reason streamerF mutants make very long aggregation streams is that the cells chemotax very slowly.
Figure 10 (caption pdf page 90, figure page 91) shows the outlines of a single ameba that moved ~50 um in 60 minutes (and not much further in the entire 90 minutes). The large streams of stmF amebae grown on Ecoli on SM1 or SM5 plates can be explained by the leading edge of the colony expands faster than the starved amebae chemotax inwards to the initial aggregation centers.
- dictyostelium discoideum,
- cyclic GMP,
- morphogenetic mutant
Available at: http://works.bepress.com/gmcnamara/39/