par Denis, Suzanne ;Devlin, Thomas T.M.
Référence Experimental cell research, 52, 2-3, page (308-318)
Publication Publié, 1968-10
Article révisé par les pairs
Résumé : Oligomycin, an inhibitor of oxidative phosphorylation, did not cause an immediate cessation of development of Pleurodeles waltlii or Xenopus laevis eggs. Development was inhibited at a subsequent stage; with treatment prior to cleavage, at blastula, or early gastrula stages, development continued to the blastula, early gastrula and late gastrula stages respectively. The lack of immediate inhibition was not due to lack of penetration of the oligomycin into the cells, because (1) respiration was inhibited approx. 50 per cent within 1 h and (2) treatment with oligomycin for 3 h was sufficient to cause inhibition of development which was not detectable until 18 to 20 h later. The ATP levels of the cells were not decreased significantly by the presence of the inhibitor, even after 18 h of treatment. Eggs whose development was inhibited by oligomycin at a particular stage were not observably different from control eggs at the same stage of development; only when the treated eggs were maintained in the inhibited stage for long periods (48 h or more) did degenerative changes occur. 2,4-Dinitrophenol, an uncoupler of oxidative phosphorylation, in the presence or absence of oligomycin inhibited development immediately. Rotenone, an inhibitor of mitochondrial respiration, also inhibited development and oxygen utilization of the eggs at the time of addition. The results suggest that ATP specifically derived from oxidative phosphorylation is not required for early development of amphibian eggs. Apparently substrate-level phosphorylation can maintain an adequate supply of ATP. The results also indicate that part of the energy for the developing egg is derived directly from "high energy" intermediates of oxidative phosphorylation. The significance of these results is discussed. © 1968.

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