The assembly of the DNA complex present in chick embryo cell cytosol

Abstract

1. 1. Chromatography of chick embryo fibrobast cytosol labelled with [ 3H]thymidine or [ 3H]uridine precursors has shown the presence of early labelled DNA and RNA eluting at a position corresponding to a relative molecular mass of approximately 1.5–10 5. 2. 2. The early DNA-RNA (heteroduplex?) then moves progressively to a higher molecular weight peak, relative molecular mass approximately 10 6. 3. 3. The process appears similar in cytosol from cultured cells and from whole aminiotically labelled chick embryo: consequently the cytosolic DNA complex is not an artefact of cell culturing. 4. 4. The relative contribution of artefactual and specific cytosol-associated DNA material is discussed: it is concluded that while both are present in cytosol as prepared, it is possible to discriminate between specific and artefactual DNA material.