Fine Structure of the Mastigont System in Tritrichomonas foetus (Riedmüller)*

Abstract

SYNOPSIS. Tritrichomonas foetus shares many fine‐structural features with the previously described genera of the subfamily Trichomonadinae. These include the arrangement and structure of the kinetosomes, of most rootlet filaments, including the sigmoid filaments of kinetosome #2, as well as those of the parabasal apparatus and of the pelta‐axostyle complex. On the other hand, this species, and presumably all other Tritrichomonas augusta‐type flagellates, differ from Trichomonadinae in certain important details. Among the features which T. foetus does not share with Trichomonadinae are the fine structure of the costa and of the undulating membrane, as well as several organelles not found in the latter subfamily. The costal base of Trichomonadinae is replaced in T. foetus and other Tritrichomonadinae by a comb‐like structure, extending between the costa and the infrakinetosomal body. The suprakinetosomal body, connected to kinetosome #2 in the region of attachment of the sigmoid filaments, and the infrakinetosomal body, which appears to contribute to the proximal marginal lamella, are organelles evidently restricted to Tritrichomonadinae. The undulating membrane consists of 2 parts. The proximal part is a fold‐like differentiation of the dorsal body surface, the dorsal part of which contains the proximal marginal lamella. The distal part of the undulating membrane, with no obvious physical connection to the fold, encloses the distal marginal lamella in its ventral, and the microtubules of the recurrent flagellum in its dorsal area. The organelle of T. foetus which by its size, certain structural characteristics, and relationship with the undulating membrane and some organelles, including the paracostal granules, is analogous to the costa of Trichomonadinae and of Trichomitopsis termopsidis (subfamily Tritrichomonadinae), conforms in the structure of its periodic cross‐striations to that of the parabasal filaments of the latter organisms; its origin corresponds closely to that of parabasal filament 2 of Trichomonadinae.

Fine structure and isozymic characterization of trichomonadid protozoa

“…No morphological or size difference was found among the strains of T. suis isolated from either the nasal cavity or the digestive tract of swine. Under electron microscopy, T. suis and T. foetus could not be differentiated; the mastigont system, the origin and periodicity of the costae, the presence of the comb, and the localization and ultrastructural features of the hydrogenosomes as well as all the other cellular structures were identical to those previously reported for T. foetus (Honigberg et al 1971;Benchimol et al 1982Benchimol et al , 1996Benchimol and De Souza 1983). The ultrastructural localization of carbohydrates using the Thiéry (1967) technique was also the same in both species as reflected by the arrangement and distribution of glycogen granules and the positive reaction in the same membranous structures.…”

The ecology and feeding biology of thecate heterotrophic dinoflagellates

“…These structures are similar to the rod-shaped bodies seen within the peduncular microtubular basket of Gymnodinium lebouriae (Lee, 1977), Katodinium fungiforme (Spero 1982), and of Peridiniopsis berolinense (Wedemayer and Wilcox, 1984) and may be contain digestive enzymes. Protoperidinium, there exists a cytoplasmic region partially bound by a single row of microtubules, the latter which are termed the pelta-axostyle complex (Honigberg et al, 1971;Brugerole, 1980).…”

Molecular identification and phylogenetic relationships of trichomonad isolates of galliform birds inferred from nuclear small subunit rRNA gene sequences

“…Such reduction of the cytoskeleton in the course of evolution was for instance obvious for the Monocercomonadidae Histomonas meleagridis (Gerbod et al 2001). This species which has four basal bodies, three of them being barren, and a reduced microtubular cytoskeleton called axostyle-pelta complex (Rybicka et al 1972;Schuster 1968) was shown to be derived from a more complex form, the Trichomonadidae Tritrichomonas as revealed by the possession of four flagella, a well-developed axostyle-pelta complex, a large striated root, the costa, and a complex locomotory organelle, the undulating membrane (Honigberg et al 1971).…”