See commentaries and letters to the editor in Nature, in attachments. Cheers, Roeland -- Roeland Merks Department of Plant Systems Biology VIB / Ghent University Technologiepark 927 B-9052 Ghent, Belgium http://www.psb.ugent.be Tel. +32-(0)9-33 13825 email: post@roelandmerks.nl http://www.roelandmerks.nl weblog: http://biolog.volkskrantblog.nl