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.

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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.

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20180504F update: Giving credit where credit is due.

My dissertation cites Verschueren and van Larabeke (1984) for their invention of areal speeds (Bob Futrelle's and my name for shape differences). I wanted to cite them here on the bepress "39" cover page. Bob and I extended this to more time points (time area!!!) with temporal area maps (TAM). We realized immediately, but not practical circa 1984, that this could also be extended to "temporal volume maps" (TVM). With Fura-2 and other small molecule indicators, and fluorescent protein biosensors, and now (circa 2018) "hybrid sensors" (hybrid biosensors, i.e. Loren Looger's iGluSnFr meets Luke Lavis's Janelia Fluors) can also layer in ions, enzyme activities, spatial localizations, etc. My dissertation reference list should also be looked on as giving credit to many others publications, and occasional visitors, plus UIUC colleagues, such as members of my dissertation committee, and colleagues.

Verschueren H, van Larabeke N (1984) A new model for the quantitative analysis of cell movements in vitro: Definition of a shape change factor. Cytometry 5: 557-561 

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