COMPARATIVE ANALYSES OF THE DINOFLAGELLATE FLAGELLAR APPARATUS. I. WOLOSZYNSKIA SP.¹

Abstract

The three‐dimensional structure of the flagellar apparatus in Woloszynskia sp. was determined. This recently discovered dinoflagellate possesses two basal bodies that are offset from one another and lie at an angle of approximately 110°. The transverse basal body is associated with a striated fibrous root assemblage that consists of two differently staining fibrous portions with identical striation periodicity. Unlike the transverse striated fibrous roots reported in other dinoflagellates, this assemblage extends to the cell's right beyond the proximal end of the transverse basal body. The striated fibrous root complex is attached to the anterior end of the longitudinal microtubular root by a broad striated fibrous connective. The longitudinal basal body is also associated with the longitudinal microtubular root. The flagellar opening of each emerging axoneme is surrounded by a striated collar. The striated collars are linked to one another by a striated fibrous, striated collar connective. The variations and similarities of the flagellar apparatus and the ventral ridge/striated collar connective in Woloszynskia sp. are compared to similar components in other dinoflagellates.

Studies on Woloszynskioid Dinoflagellates X: Ultrastructure, Phylogeny and Colour Variation in Tovellia rubescens n. sp. (Dinophyceae)

“…The nearly straight proximal part of the LMR/r1 that projects ventrally past the LB is another feature in common with species of Tovelliaceae for which the disposition of flagellar roots is known in enough detail (Calado ; Calado et al. ; Roberts and Timpano ; Roberts et al. ).…”

“…closely matched what has been described from other members of the Tovelliaceae, particularly the relative positioning of the basal bodies, with the nearly 400-nm distance between their proximal ends highlighted by the large SRC and its connection to the proximal part of the TSR (see summary of tovelliacean characters in Calado 2011). The nearly straight proximal part of the LMR/r1 that projects ventrally past the LB is another feature in common with species of Tovelliaceae for which the disposition of flagellar roots is known in enough detail (Calado 2011;Calado et al 2006;Roberts and Timpano 1989;Roberts et al 1995). The arrangement of roots and connectives near the flagellar bases is consistently different in species of Peridiniales, in which the SRC is replaced by a much wider layered connective, which spans a rather shorter distance between the TSR and a fibrous layer on the dorsal face of the LMR/r1 (Calado et al 1999;Craveiro et al 2009Craveiro et al , 2013Craveiro et al , 2015.…”

GENERAL ULTRASTRUCTURE AND FLAGELLAR APPARATUS ARCHITECTURE OF WOLOSZYNSKIA LIMNETICA (DINOPHYCEAE)

“…Cells were maintained in a modified (Starr and Zeikus 1993) Volvox medium (Provasoli and Pintner 1959) at room temperature with a 14: 10 h LD cycle. Cells were fixed for scanning and transmission electron microscopy (TEM) following the methods described by Roberts and Timpano (1989). Cells were sectioned with an RMC-6000 ultramicrotome, stained with an LKB Ultrostainer, and viewed on a Hitachi S-450 scanning electron microscope (SEM) and an H-600 TEM.…”

“…Wilcox ( , 1989 focused on the chloroplasts and multilayered structures in W. pascheri (Suchlandt) von Stosch and did not extend the report to a comparative cytological overview. Roberts and Timpano (1989) restricted their studies of W. sp. to the flagellar apparatus and used the description of the cell as published in the abstract of Timpano and Pfiester (1 987) to suffice until Pfiester could formally describe and name this new species (Pfiester, pers.…”

“…Woloszynskia limnetica was chosen because its external morphology is similar to that of W. sp. (Roberts and Timpano 1989) and because it is available through one or more culture collections,…”