Ultrastructure of the ribonucleoprotein and messenger-like ribonucleic acid of the polyribosomes isolated from Rous sarcoma virus-induced mouse ascites sarcoma cells

Electron microscopic observation was made on the length distibution of messenger RNA molecules in polyribosome pre· paration isolated from mouse ascites sarcoma cells, which was de· stroyed by ethylenediamine tetraacetate treatment in hypotonic solu. tion. The ribosomes appeared first to be a hollowed structure by swelling and then were destroyed to a rod·like structure consisting of ribonucleoprotein strand, which was clearly distinguishable from the linear structure of messenger RNA released from the polyribosomes. The length of messenger RNA was poly.dispersed measuring from 0.02 up to 6 μ, the majority (92%) of which was in the length less than 3 μ with a prominent peak between 0.6 to 0.8 μ.