Chromatin remodeling in nuclear cloning


  • Dedication: This Minireview Series is dedicated to Dr Alan Wolffe, deceased 26 May 2001.

N. Kikyo, Stem Cell Institute and Department of Medicine, University of Minnesota, Mayo Mail Code 716, 420 Delaware St. SE, Minneapolis, MN 55455, USA. Fax: + 1 612 6242436, Tel.: + 1 612 6240498, E-mail:


Nuclear cloning is a procedure to create new animals by injecting somatic nuclei into unfertilized oocytes. Recent successes in mammalian cloning with differentiated adult nuclei strongly indicate that oocyte cytoplasm contains unidentified remarkable reprogramming activities with the capacity to erase the previous memory of cell differentiation. At the heart of this nuclear reprogramming lies chromatin remodeling as chromatin structure and function define cell differentiation through regulation of the transcriptional activities of the cells. Studies involving the modification of chromatin elements such as selective uptake or release of binding proteins, covalent histone modifications including acetylation and methylation, and DNA methylation should provide significant insight into the molecular mechanisms of nuclear dedifferentiation and redifferentiation in oocyte cytoplasm.