Eukaryotic DNA replication

One of the fundamental characteristics of life is the ability of an entity to reproduce itself, which stems from the ability of the DNA molecule to re plicate itself. The initiation step of DNA replication, where control over the timing and frequency of replication is exerted, is poorly understood in eukaryotes in general, and in mammalian cells in particular. The cis-actin g DNA element defining the position and providing control over initiation i s the replication origin. The activation of replication origins seems to be dependent on the presence of both a particular sequence and of structural determinants. In the past few years, the development of new methods for ide ntification and mapping of origins of DNA replication has allowed some unde rstanding of the fundamental elements that control the replication process. This review summarizes some of the major findings of this century, regardi ng the mechanism of DNA replication, emphasizing what is known about the re plication of mammalian DNA. (C) 1999 Wiley-Liss, Inc.