title: Cleavage in a saponin model of the sea urchin egg.
abstract: A cell model, in which cleavage could be induced, was obtained from fertilized sea urchin eggs by putting eggs that were in the first cleavage into a solution containing 3 X 10(-5) g/ml saponin and suitable amounts of ATP and Ca2+. The cell membrane became freely permeable to ATP and Ca2+ within 1 minute. The respective optimal concentrations of ATP and Ca2+ that advanced the cleavage furrow in this model were 2 mM and 10(-8) M. With the optimal ATP and Ca2+ concentrations, the cleavage furrow of the model advanced at a rate that differed little from that in living eggs. The cleavage furrow soon receded, however, when the concentration of ATP was decreased to less than 1 mM or increased to more than 3 mM, as well as when the concentration of Ca2+ was increased to more than 10(-7) M.
mesh_terms: D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D002118:Calcium / Q000502:physiology; D002455:Cell Division; D002463:Cell Membrane Permeability; D005260:Female; D008954:Models, Biological; D012503:Saponins; D012617:Sea Urchins / Q000196:embryology*; D015053:Zygote / Q000166:cytology*
chemical_list: D012503:Saponins; D000255:Adenosine Triphosphate; D002118:Calcium