caa a22 4500 378925229 CHVBK 20180305123615.0 cr unu---uuuuu 161128e20040226xx s 000 0 eng 10.1515/BOT.2004.006 doi (NATIONALLICENCE)gruyter-10.1515/BOT.2004.006 Sexual behaviour, auxosporulation and chloroplast dynamics in a marine Amphora (Bacillariophyceae) studied in culture [Elektronische Daten] [Koen Sabbe, Victor A. Chepurnov, David G. Mann, Wim Vyverman] Chloroplast, mating behaviour, and auxosporulation are described for Amphora cf. proteus Gregory. The interphase chloroplast is butterfly-shaped and lies with its central part, containing a flat discoid pyrenoid, pressed against the ventral side of the girdle. Chloroplast division is longitudinal and begins and ends before mitosis and cytokinesis. Over the cell cycle, no rotations or lateral translocations of the chloroplast were noticed. A. cf. proteus is the first species of this genus in which sexual reproduction and breeding behaviour have been studied in clonal cultures. The cells isolated exhibited strictly dioecious behaviour, reproducing only in mixed cultures of sexually compatible clones. Sexual reproduction in A. cf. proteus is morphologically and behaviourally isogamous. Each gametangium forms two functional gametes, which do not rearrange within the gametangium, and two small aborted cells. The aborted cells are produced after an unequal cytokinesis accompanying meiosis II; the second cytokinesis during gametogenesis represents a phenomenon hitherto unknown in pennate diatoms. Auxospore development takes place by bipolar expansion. The expansion is unequal on the two long sides of the auxospore, so that the auxospore becomes curved and dorsiventral. The auxospore forms a transverse and longitudinal perizonium. Copyright © 2004 by Walter de Gruyter GmbH & Co. KG Hydrobiology nationallicence Mycology, fungi nationallicence Botany & plant sciences nationallicence Sabbe Koen aut Chepurnov Victor A. aut Mann David G. aut Vyverman Wim aut Botanica Marina Walter de Gruyter 47/1(2004-02-26), 53-63 0006-8055 47:1<53 2004 47 botm https://doi.org/10.1515/BOT.2004.006 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/BOT.2004.006 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sabbe Koen aut NATIONALLICENCE 700 1- Chepurnov Victor A. aut NATIONALLICENCE 700 1- Mann David G. aut NATIONALLICENCE 700 1- Vyverman Wim aut NATIONALLICENCE 773 0- Botanica Marina Walter de Gruyter 47/1(2004-02-26), 53-63 0006-8055 47:1<53 2004 47 botm CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter