Role of polyamines in proliferation and differentiation of Dictyostelium discoideum as ascertained by difluoromethylornithine treatment.

: The role of polyamines on growth and early development of D. discoideum has been investigated following the activity of ornithine decarboxylase (ODC) and the effects of difluoromethylornithine in vivo. Pretreatment of growing amoebae with difluoromethylornithine inhibited proliferation and markedly reduced the decarboxylase activity in the first hour after fasting without affecting the subsequent development. These results show the essentiality of ODC for proliferation but are inconsistent with the hypothesis atributing a developmental role to the transient increase in ODC shortly after D. discoideum starvation.