Fig. 2

Physcomitrella sperms in fixed samples. a, b A developing antheridium. c, d An antheridium containing differentiated sperms, note the swollen apical cell of the antheridium. The inner space of the antheridia is indicated in white line in b and d. e, f A sperm mass released from an antheridium. g, h Magnified sperms. Images show the same view in bright field (right) and fluorescence channels. DNA was stained with DAPI. Scale bars 20 µm in a–f; 10 µm in g, h