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Contact inhibition of cell movement in living embryos of an annual fish, Nothobranchius korthausae : Its role in the switch from persistent to random cell movement

1979; Wiley; Volume: 207; Issue: 3 Linguagem: Inglês

10.1002/jez.1402070314

1097-010X

Roland J. Lesseps, Marian V. Hall, Mary Beth Murnane,

Reproductive biology and impacts on aquatic species

Abstract The deep blastomeres of annual fish embryos emigrate from the blastodisc to wander as single cells, during epiboly and early dispersed stages, between the periblast and the enveloping layer cells. Time‐lapse films of the deep blastomere movements were analyzed to determine whether the cells move persistently or randomly and whether or not they show contact inhibition of cell movement. Certain predictions which follow from the random‐walk model (uniform distribution of intersegmental angles, exponential distribution of squared segmental lengths, and a straight‐line plot – passing through the origin – of mean square displacement against time) were tested and, in general, found to apply to these deep blastomeres during dispersed phase 1 but not during epiboly stages. These results indicate that the cells tend to persist in their direction of movement during epiboly, but not during dispersed phase 1, when their movement is random. Upon completion of epiboly, there is a decrease in cell motility, as measured by the augmented diffusion constant, D *, and an increase in the average collision rate. Numerous cases of cell contact between deep blastomeres were observed (297 during epiboly and 167 during dispersed phase 1); in every case one or both cells changed their direction of movement. The role this contact inhibition might play in the persistent movement of epiboly and the random movement of dispersed phase 1 is discussed.