NEW SYSTEMS FOR REPLICATING DNA IN-VITRO

Current paradigms for the regulation of genomic DNA replication in euk aryotes are derived primarily from cell fusion experiments, yeast gene tics, and from in vitro assays in Xenopus egg extracts. Initially, man y aspects seemed irreconcilably different among the various organisms and model systems. In the past year, however, divergent approaches hav e arrived at a consensus on how the cell cycle regulates the initiatio n of DNA replication. All major players appear to be conserved from ye ast to vertebrates, yet the important challenge of reconstituting euka ryotic replication from purified components remains. Three novel in vi tro assays that replicate nuclear templates bring us closer to this go al.