EPIDERMAL POLYAMINE LEVELS RELATED TO CELL-CYCLE EVENTS DURING THE METAMORPHOSIS OF TENEBRIO-MOLITOR L (INSECTA, COLEOPTERA) - EFFECT OF JUVENOID APPLICATION

1. Three polyamines were separated by reverse-phase HPLC and detected by fluorescence in Tenebrio epidermis: putrescine, spermidine and spermine. 2. The levels of these compounds varied during metamorphosis: one peak was observed during the G2-arrest preceding the pupal-adult mitotic crisis and a second occurred when cells were again G2-arrested after the mitotic period. 3. A juvenile hormone analogue, which inhibits the G2-M transition preparing cells to the adult mitoses, was unable to prevent the first polyamine increase suggesting that juvenile hormone does not act on further development via inhibition of polyamine synthesis.