Double strandedness of nascent DNA of a higher plant (Vicia faba).
After a pulse of 5-10 min with [3H]thymidine, labeled DNA extracted from embryonic axes of Vicia seeds sedimented as a rather homogeneous peak at approx. 10S in an alkaline sucrose density gradient, as described in our previous paper ((1975) Biochim. Biophys. Acta 395, 314-321). The sedimentation pattern of the same pulse-labeled DNA in a neutral gradient showed a wide range of sizes from approx. 14 S to more than 40 S. However, most of these labeled DNA components, including the 14-20 S shorter fragments, were shown to have a double-stranded structure by hydroxyapatite column chromatography. Further investigations on neutral sucrose gradients revealed a decreased occurrence after a chase, and final disappearance after a longer chase period of these shorter double-stranded fragments. A possible secondary structure of the newly synthesized DNA in a higher plant (Vicia faba) is discussed.
D002499:Centrifugation, Density Gradient; D004247:DNA / Q000096:biosynthesis; D004261:DNA Replication; D008970:Molecular Weight; D010944:Plants / Q000378:metabolism*
D004247:DNA