Department of Genome Analysis, GBF-German Research Centre for Biotechnology, Mascheroder Weg 1, D-38124 Braunschweig, Germany. GerhardKauer@t-online.de|Department of Genome Analysis, GBF-German Research Centre for Biotechnology, Mascheroder Weg 1, D-38124 Braunschweig, Germany. GerhardKauer@t-online.de