Three-Dimensional Scroll Waves Organize Dictyostelium Slugs (original) (raw)
1992, Proceedings of The National Academy of Sciences - PNAS
To test the hypothesis that periodic signals and chemotaxis direct later morphogenesis in Dictyostelium discoideum, we investigated cell behavior and cell movement in slugs. Trails of neutral red-stained prestalk and anterior-like cells were recorded by high-resolution digital image processing. Neutral red-stained anterior-like cells in the prespore zone of slugs move straight forward in the direction of slug migration and, furthermore, show coherent periodic cell movement. In contrast, cells in the prestalk zone move along completely different trajectories. Prestalk cells move perpendicular to the direction of slug migration; that is, they rotate around the tip. The cell movement data show that the chemotactic signal in the slug propagates as a three-dimensional scroll wave in the prestalk zone and as a planar wave in the prespore zone. The different behavior of prestalk and prespore cells is most likely caused by a difference in the oscillatory properties of the two cell types. We...
Sign up for access to the world's latest research.
checkGet notified about relevant papers
checkSave papers to use in your research
checkJoin the discussion with peers
checkTrack your impact
Related papers
Twisted scroll waves organize Dictyostelium mucoroides slugs
Journal of cell science, 1997
Cellular slime moulds (Dictyosteloids) are characterised by at least two different modes of slug migration. Most species, e.g. Dictyostelium mucoroides, produce a stalk continuously during slug migration, while a few species, e.g. Dictyostelium discoideum are characterised by stalk-less slug migration and only produce a stalk upon culmination. Experiments on D. discoideum and theoretical model calculations have shown that D. discoideum slugs are organized by a cAMP scroll wave in the tip which produces planar waves in the back. These waves guide cell movement in slugs: spiralling in the tip and forward movement parallel to the slug axis in the back. Simple changes in model parameters can lead to the formation of a twisted scroll wave which extends throughout the slug. In order to investigate whether such twisted scroll waves occur naturally we have analysed the movement of fluorescently labelled single cells in migrating D. mucoroides slugs. The results show that cells in the prespo...
Optical flow analysis of the ventral cellular layer of the migrating Dictyostelium discoideum slug
Microbiology, 1994
A digital image analysis system for extracting motion information from timevarying digital light microscopy images is presented. This system is then used to map out the movement profile of the surface layer of cells in contact with the substratum through the extracellular matrix (ECM) of the migrating Dictyostelium discoideum slug. From digital high magnification light microscopy images, the morphology of moving cells within the tail region of a young migrating wild-type WS380B slug is described, and compared with the morphology of streaming D. discoideum cells. It is shown that: (i) when the migrating tip of the slug touches the agar substrate, cells in the anterior ventral surface layer of the tip region slow dramatically; (ii) overall cell movement in the ventral surface layer of the migrating D. discoideum slug is slower than the movement of the slug as a whole; and (iii) in less than 10% of cases a wave of movement (groups of cells synchronously slowing down and then accelerating forward) propagates down the slug axis a t approx. 1.2 pm s-l. The time interval between waves may be related to the time interval between tip-to-substratum contact that is periodically re-established during normal WS380B slug migration after each aerial projection of the tip. Abbreviation: ECM, extracellular matrix. Ultimately, to understand how the slug of D. discoidezlm migrates, requires knowledge of how the cells within the slug move (Williams e t al., 1986; Breen & Williams,
Analysis of cell movement during the culmination phase of Dictyostelium development
Development (Cambridge, England), 1996
Co-ordinated cell movement of tens of thousands of cells and periodic signals characterise the multicellular development of the cellular slime mould Dictyostelium discoideum. We investigated cell movement by analysing time-lapse video recordings made during the slug stage and the culmination phase of Dictyostelium development. Slugs viewed from the side showed an even, straight forward movement with the tip slightly raised in the air. Slugs that had migrated for a prolonged period of time either culminated or showed a behaviour best described as abortive culmination. Culmination is initiated by a local aggregation of anterior-like cells at the base of the slug at the prestalk-prespore boundary, where they form a stationary mass of cells. Prespore cells continue to move forward over this stationary pile and, as a result, are lifted into the air. The stationary group of anterior-like cells thereby end up to the back of the slug. At this point the slug either falls back on the agar sur...
Movement of the multicellular slug stage of Dictyostelium discoideum: an analytical approach
Time-lapse video recordings of migrating multicellu-lar slugs of Dictyostelium discoideum were subjected to image analysis. A transient 'collar-like' structure was identified at the anterior end of the slug. This collar remains stationary in the wild-type strain WS380B; it is observed shortly after the advancing tip contacts the substratum. Stationary collars formed approximately every 12 min; they were matched with patterns revealed on the underside of slime trails with FITC-coupled monoclonal antibody MUD50. It is proposed that stationary collars are involved with the forward movement of the slug. The mutant strain HU2421 lacks the MUD50-epitope and forms collars which do not remain stationary but move backwards along the slug to collect at a 'waist' region. The slipping-collars observed in the mutant corre-lated with very slow migration rates. We propose that HU2421 moves slowly because it lacks traction.
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.