Mosses as Model Systems for the Study of Metabolism and Development David Cove, 1,2 Magdalena Bezanilla, 3 Phillip Harries, 4 and Ralph Quatrano 2 1 Center for Plant Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom; email: d.j.cove@leeds.ac.uk 2 Department of Biology, Washington University, St. Louis, Missouri 63130-4899 3 Department of Biology, University of Massachusetts, Amherst, Massachusetts 01002-9297 4 Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401 Annu. Rev. Plant Biol. 2006. 57:497–520 The Annual Review of Plant Biology is online at plant.annualreviews.org doi: 10.1146/ annurev.arplant.57.032905.105338 Copyright c  2006 by Annual Reviews. All rights reserved First published online as a Review in Advance on February 1, 2006 1543-5008/06/ 0602-0497$20.00 Key Words auxin, cytokinin, abscisic acid, cell polarity, cytoskeleton Abstract The haploid gametophyte stage of the moss life cycle is amenable to genetic and biochemical studies. Many species can be cultured on simple defined media, where growth is rapid, making them ideal ma- terial for metabolic studies. Developmental responses to hormones and to environmental inputs can be studied both at the level of in- dividual cells and in multicellular tissues. The protonemal stage of gametophyte development comprises cell filaments that extend by the serial division of their apical cells, allowing the investigation of the generation and modification of cell polarity and the role of the cy- toskeleton in these processes. Molecular techniques including gene inactivation by targeted gene replacement or by RNA interference, together with the nearly completed sequencing of the Physcomitrella patens genome, open the way for detailed study of the functions of genes involved in both development and metabolism. 497 Annu. Rev. Plant. Biol. 2006.57:497-520. Downloaded from arjournals.annualreviews.org by David Cove on 07/07/06. For personal use only.