Induction of DNA synthesis or apoptosis in mammalian nuclei by Xenopus egg extracts that fail to support the replication of sperm chromatin

Abstract

Cell-free extracts of Xenopus eggs are widely used to study DNA replication in higher eukaryotes. However, with Xenopus sperm chromatin as template, it is a common experience that the efficiency of replication varies from extract to extract, for reasons that are unclear. Here we show that the majority of extracts unable to support sperm replication are nevertheless able to induce DNA synthesis in intact mammalian nuclei. Those that do not, induce apoptosis.