Nuclear reconstitution of demembranated Orychophragmus violaceus sperm in Xenopus laevis egg extracts

The cell-free extracts from animal Xenopus laevis egg could induce chromatin decon-densation and pronuclear formation from demembranated plant (Orychophragmus violaceus) sperm. The demembranated Orychophragmus violaceus sperm began to swell in 30 min incubation, and then were gradually decondensed. The reassembly of nuclear envelope in the reconstituted nuclei had been visualized by means of electron microscopy and fluorescent microscopy. Membrane vesicles fused to form the double envelope around the periphery of the decondensed chromatin. The morphology of the newly formed nucleus, with a double membrane, was similar to those nuclei after fertilization. Transmission electron microscope micrograph of the whole mount prepared nuclear matrix-lamina showed the reconstituted nucleus to be filled with a dense network.