Essential role of the polyamines in early chick embryo development.
The polyamines putrescine, spermidine and spermine were analyzed in chick embryos during the first 2 days of development. A rapid increase in the activity of ornithine decarboxylase (ODC), the initial and rate-limiting enzyme in polyamine synthesis, was observed immediately after onset of incubation. Peak activities were found at 15 and 23 h of incubation. The first peak coincides with gastrulation and the second peak with early neurulation in the embryo. All three polyamines varied in a similar manner as did ODC, with putrescine and spermidine at about the same level and spermine at a lower level. The ODC activity was blocked by alpha-difluoromethylornithine, an enzyme-activated irreversible inhibitor. The inhibitor was administered to embryos in ovo at 5 h of incubation, i.e. prior to the first major increase in ODC activity. This block prevented the accumulation of the polyamines and inhibited development as gastrulation, suggesting a decisive role for polyamines in this developmental event.
D000818:Animals; D002642:Chick Embryo / Q000378:metabolism / Q000502:physiology*; D002970:Cleavage Stage, Ovum / Q000378:metabolism; D005775:Gastrula / Q000378:metabolism; D009420:Nervous System / Q000196:embryology; D009955:Ornithine Decarboxylase / Q000378:metabolism; D065108:Ornithine Decarboxylase Inhibitors; D011073:Polyamines / Q000378:metabolism*; D011700:Putrescine / Q000096:biosynthesis; D013095:Spermidine / Q000096:biosynthesis; D013096:Spermine / Q000096:biosynthesis
D065108:Ornithine Decarboxylase Inhibitors; D011073:Polyamines; D013096:Spermine; D009955:Ornithine Decarboxylase; D013095:Spermidine; D011700:Putrescine