Developmental physiology of cestodes — XII role of preformed informational RNA in development of Hymenolepis diminuta

Abstract

1. 1. Inhibition of protein synthesis by 15·.9 μM Actinomycin-D (AM-D) was approximately 25 per cent in 4- and 6-day old Hymenolepis diminuta. 2. 2. Inhibition increased to greather than 90 per cent in the germinative region of worms later in the growth period. 3. 3. Inhibition was always least in the terminal proglottids, thus demonstrating that much of the informational RNA required for complete proglottid maturation was synthesized prior to the differentiation of this region. 4. 4. In vitro cultivation in the presence of AM-D suppressed development to various degrees according to the length of exposure to the drug; however, complete inhibition of development was not observed. 5. 5. It is concluded that the presence of preformed m-RNA may help account for the lack of a crowding effect until worms are more than 6 days old.