Transitivity, pattern-reversal, engulfment and duality in exchange-type cell aggregation kinetics - Antonelli, P.; McLaren, D.I.; Rogers, T.D.; Lathrop, M.; Willard, M.A. (Elsevier)
Simulations of cell-sorting phenomena in embryogenesis describable by means of the differential adhesion mechanism are further studied using the exchange model. In this study, more than two cell-types are employed and results nicely complement the successes of earlier work with only two cell-types. Again, it is noticed that ''central clumping'' does not usually appear in final distributions. In addition, the phenomena of transitivity, pattern-reversal and the engulfment of one tissue by another are studied. The first is shown to be a trivial consequence of Steinberg's stochastic version of differential adhesion. Also, it is shown that the exchange model successfully simulates pattern-reversal by the reversal of the relative adhesion values due to the time-in-culture reversal of the effect of adhesivity of trypsin-assisted dissociation of tissues. The connection between the occurrence of pattern reversal and the absolute and relative positions of tissue types in the adhesion hierarchy is explained in terms on the exchange model. It is found that the model, as it stands, does not seem to give a satisfactory basis for the simulation of engulfment. Suggestions for the extension of the exchange principle are made which will perhaps rectify this limitation. It is felt that any real system which exhibits engulfment will also exhibit central clumping, and conversely. The importance of the figure-ground ambiguity we have called ''duality'' is again stressed. If this ambiguity is not taken into account in experimental work, interpretation of many results on cell-sorting are rendered meaningless.
http://dx.doi.org/10.1016/S0022-5193(75)80042-7
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