Protein synthesis in Artemia salina embryos : I. Studies on polyribosomes

Abstract

A study of polyribosomes from encysted embryos of the crustacean Artemia salina has been carried out by sucrose density gradient centrifugation. Although no discrete polyribosome peaks were detected in extracts from hydrated-dormant gastrulae, a small amount of ribonuclease-sensitive material sedimenting below the ribosomes was present. Formation of small polyribosomes has been detected within 5 minutes after the dormant gastrulae were permitted to resume metabolism and development by incubation at 30°C. The increase in polyribosome content which occurred with further incubation appeared to result chiefly from the formation of heavier polyribosomes. Using NaH 14CO 3 as a precursor, protein synthesis has been detected in intact gastrulae within the first 15 minutes after the end of dormancy. Polyribosomes were shown to be functional by their in vitro incorporation of leucine- 14C into hot trichloroacetic acid-insoluble material. An evaluation has been made of the method used for the study of polyribosomes in Artemia.