Regulated chromosomal DNA replication in the absence of a nucleus

Mol Cell. 1998 Mar;1(4):519-29. doi: 10.1016/s1097-2765(00)80052-0.


Using Xenopus egg extracts, we have developed a completely soluble system for eukaryotic chromosomal DNA replication. In the absence of a nuclear envelope, a single, complete round of ORC-dependent DNA replication is catalyzed by cytosolic and nuclear extracts added sequentially to demembranated sperm chromatin or prokaryotic plasmid DNA. The absence of rereplication is explained by an activity present in the nucleus that prevents the binding of MCM to chromatin. Our results indicate that the role of the nuclear envelope in DNA replication is to concentrate activators and inhibitors of replication inside the nucleus. In addition, they provide direct evidence that metazoans use the same strategy as yeast to activate DNA replication and to restrict it to a single round per cell cycle.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cell Cycle Proteins / metabolism
  • Cell Extracts / pharmacology
  • Chromosomes / metabolism*
  • Cytoplasm / metabolism*
  • DNA Replication*
  • Interphase / physiology
  • Male
  • Nuclear Envelope / metabolism*
  • Oocytes / metabolism*
  • Plasmids
  • Spermatozoa / drug effects
  • Xenopus
  • Yeasts / genetics
  • Yeasts / metabolism


  • Cell Cycle Proteins
  • Cell Extracts