[The possible role of cellular proto-oncogenes in early embryonic development].

A brief review about the possible role of cell protooncogenes in embryonal development and neoplastic transformation is presented.

Messenger RNA is translated when associated with the cytoskeletal framework in normal and VSV-infected HeLa cells.

When the cytoskeletal framework is prepared from suspension-grown HeLa by extraction with nonionic detergent, all the polyribosomes are associated with the framework while 80% of tRNA and the major portion of monoribosomes as well as 75% of the cell proteins are found in the soluble fraction. The mRNA of polyribosomes is bound to the cytoskeleton and these molecules remain attached even after polyribosomes are disassembled in vivo prior to extraction. Although all actively translating message molecules are attached to the framework, about one quarter of the poly(A)+ mRNA is free of the framework.