Report

Regulation of Replicon Size in Xenopus Egg Extracts

+ See all authors and affiliations

Science  14 Feb 1997:
Vol. 275, Issue 5302, pp. 993-995
DOI: 10.1126/science.275.5302.993

You are currently viewing the abstract.

View Full Text

Abstract

Once a specific number of cells have been produced in the early Xenopus laevis embryo, replicon size during the S phase of the cell cycle increases. Here, it is reported that similar increase in replicon size occurred when the concentration of nuclei in replication-competent Xenopus egg extracts exceeded a critical threshold. In this system, the origin recognition complex (ORC) did not become stoichiometrically limiting for initiation, and similar amounts of this complex bound to chromatin regardless of replicon size. These data suggest that in early development, an unidentified factor controls how many preformed ORC-DNA complexes initiate DNA replication.

View Full Text

Related Content