Deviating phenotypes induced in gene-disruption library transformants. Physcomitrella wild-type and transformed plants were grown on minimal Knop medium to induce differentiation and development of gametophores. For each plant, an overview (upper row, scale bar corresponds to 1 mm) and a close-up (bottom row, scale bar equals 0.5 mm) is shown. A, Haploid wild-type moss plant completely covered with leafy gametophores and close-up of wild-type leaf. B, Transformant BC22189 affected in differentiation, mostly comprising of filamentous protonema with reduced number of gametophores, but normal leaf morphology (haploid). C, Transformant BC11280 showing retarded growth, a reduced number of gametophores per moss plant and altered leaf morphology ("drehzipfel" phenotype; twisted tips of leaves, haploid). D, Transformant BC1015 displaying altered growth habitus ("wasserpest" phenotype, reminiscent of the waterweed Elodea) and altered leaf morphology (polyploid). E, Transformant BC22288 showing retarded growth and elongated, narrow leafs (polyploid).