DNA replication of single-stranded DNA of phage fd microinjected into [formula omitted] eggs

Abstract

Single-stranded circular DNA of phage fd was microinjected into Xenopus laevis eggs and DNA synthesis was analyzed after incubation. An efficient DNA synthesis occurred in the eggs: 2.7 ng of DNA was newly formed in an egg whose volume is approximately 900 n1 during a 5-h incubation at 20° C. The DNA synthesis was sensitive to aphidicolin, suggesting that DNA polymerase α participates in the synthesis. Agarose gel electrophoresis showed that full size of fd DNA is synthesized and that replicative form I of fd DNA is the major form of the newly produced DNAs. These results suggest that priming of DNA synthesis, elongation of DNA chain and ligation of DNA strands take place co-operatively in the egg with single-stranded DNA as a template.