caa a22 4500 475817400 CHVBK 20180406123812.0 cr unu---uuuuu 170329e20000601xx s 000 0 eng 10.1007/s004970000024 doi (NATIONALLICENCE)springer-10.1007/s004970000024 Ultrastructural features of spermatocytes and spermatozoids in the fern Phyllitis scolopendrium (L.) Newm. subsp. scolopendrium [Elektronische Daten] [S. Muccifora, Sheridan L. Woo, Paolo Gori] Abstract : Phyllitis scolopendrium Newm. subsp. scolo-pendrium spermatozoids are cells 10 µm long in the form of spirals with about four turns. Their chromatin is partly honeycomb-shaped and partly highly condensed. The nuclear envelope over the latter has a regular, thin intermembrane space crossed by fibers that are probably involved in connecting the chromatin with elements of the microtubular ribbon. The cytoplasm is traversed by long cistern-shaped folds of the plasma membrane, believed to be involved in a late process of cell simplification through segregation and detachment of parts of the cytoplasm. The spermatozoids are embedded in 1-1.5 µm thick amorphous electron-transparent material containing cellulose fibrils. These fibrils are considered a network connected to the original spermatocyte wall and elements of elastic support for the amorphous material. The different polysaccharide composition of the inner and outer parts of the walls causes changes in the size and shape of the ring cells, so that the spermatozoids are pushed against and past the cap cell. The gametes are released through limited laceration of the cap cell. The laceration is due to the generally weak substructure of the cell wall. A light microscope sequence of spermatozoid release and scanning electron microscope features of newly released spermatozoids are shown. Springer-Verlag Berlin Heidelberg, 2000 Key words Phyllitis scolopendrium nationallicence Ferns nationallicence Spermatogenesis nationallicence Spermatozoid nationallicence TEM nationallicence SEM nationallicence Muccifora S. Dipartimento di Biologia Evolutiva, Università di Siena, Via P.A. Mattioli, 4, 53100 Siena, Italy e-mail: GORIPAOLO@UNISI.IT Fax: +39-577-232898, Tel. +39-577-232902, IT aut Woo Sheridan L. Dipartimento di Arboricoltura, Botanica e Patologia Vegetale, Sez. di Patologia Vegetale/CETELOBI, Università di Napoli ”Federico II”, Via dell'Università 100, 80055 Portici, Italy, IT aut Gori Paolo Dipartimento di Biologia Evolutiva, Università di Siena, Via P.A. Mattioli, 4, 53100 Siena, Italy e-mail: GORIPAOLO@UNISI.IT Fax: +39-577-232898, Tel. +39-577-232902, IT aut https://doi.org/10.1007/s004970000024 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s004970000024 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Muccifora S. Dipartimento di Biologia Evolutiva, Università di Siena, Via P.A. Mattioli, 4, 53100 Siena, Italy e-mail: GORIPAOLO@UNISI.IT Fax: +39-577-232898, Tel. +39-577-232902, IT aut NATIONALLICENCE 700 1- Woo Sheridan L. Dipartimento di Arboricoltura, Botanica e Patologia Vegetale, Sez. di Patologia Vegetale/CETELOBI, Università di Napoli ”Federico II”, Via dell'Università 100, 80055 Portici, Italy, IT aut NATIONALLICENCE 700 1- Gori Paolo Dipartimento di Biologia Evolutiva, Università di Siena, Via P.A. Mattioli, 4, 53100 Siena, Italy e-mail: GORIPAOLO@UNISI.IT Fax: +39-577-232898, Tel. +39-577-232902, IT aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer