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The characteristic structure of the mature Dictyostelium culminant is created by the regionalized cellular differentiation and directed movement of prestalk cells. The front prestalk zone of the migratory slug has previously been considered to be a homogeneous tissue. Here we demonstrate, however, the existence of multiple classes of prestalk cells located(More)
The ecmA (pDd63) and ecmB (pDd56) genes encode extracellular matrix proteins of the slime sheath and stalk tube of Dictyostelium discoideum. Using fusion genes containing the promoter of one or other gene coupled to an immunologically detectable reporter, we previously identified two classes of prestalk cells in the tip of the migrating slug; a central core(More)
This study investigated skill-based differences in anticipation and visual search strategy within open-play situations in soccer. Experienced (n = 15) and inexperienced (n = 15) subjects were required to anticipate pass destination from filmed soccer sequences viewed on a large 3-m x 3-m video projection screen. MANCOVA showed that experienced soccer(More)
Using cell-autonomous markers we have traced the origins of prespore cells and two types of prestalk cells (pstA and pstB cells) during slug formation. We show that cell sorting and positional information both contribute to Dictyostelium morphogenesis. The initial pattern established at the mound stage is topologically quite different from that of the slug.(More)
The TTGA-binding factor is a transcriptional regulator activated by DIF, the chlorinated hexaphenone that induces prestalk cell differentiation in Dictyostelium. The same activity also functions as a repressor, controlling stalk cell differentiation. We show that the TTGA-binding factor is a STAT protein. Like the metazoan STATs, it functions via the(More)
We placed a specific inhibitor of cyclic AMP-dependent protein kinase (PKA) under the control of a prestalk-specific promoter. Cells containing this construct form normally patterned slugs, but under environmental conditions that normally trigger immediate culmination, the slugs undergo prolonged migration. Slugs that eventually enter culmination do so(More)
The Dictyostelium ecmB gene encodes an extracellular matrix protein and is inducible by the stalk cell morphogen DIF. It is expressed in a subset of prestalk (pstB) cells in the slug and surrounding pstA cells first express it at culmination. A region of the ecmB promoter can direct transcription in all anterior prestalk cells, but a separate, downstream(More)
Subjects (120 young adults and 120 children) were tested for their abilities to estimate visually the distance to a target 5 m away, then walk unaided by vision to that target as accurately as possible. Experimental groups were determined by visual scanning time (1, 5, or 10 s), delay between the end of visual scanning and the start of locomotion (0, 1, 3,(More)
Highly purified steady state heterogeneous nuclear RNA from HeLa cells has been prepared by a new procedure. Detergent-washed nuclei are disrupted in 0.4 M ammonium sulfate, which also disociated contamination polysomes. The hnRNA remains bound to chromatin, which can be pelleted by gentle centrifugation. Ribonuclease inhibitors permit the preparation of(More)
One important role of DIF, the stalk cell-specific inducer of Dictyostelium, may be to divert cells from the spore cell pathway of differentiation. The D19 gene encodes an mRNA which is highly enriched in prespore over prestalk cells in the migratory slug. We show, using a mutant defective in DIF accumulation, that the concentration of D19, and several(More)