Acta Parasitologica, Vol. 51, No. 3, 2006, 182-193 Zdzislaw Swiderski(1,2)*, Jordi Miquel(3), Daniel Mlocicki(1), Lassad Neifar(4), Barbara Grytner-Ziecina(2)
and John S. Mackiewicz(5) - Ultrastructural and cytochemical studies on vitellogenesis in trypanorhynch cestode Dollfusiella spinulifera Beveridge, Neifar et Euzet, 2004 (Eutetrarhynchidae)
(1)W. Stefanski Institute of Parasitology, Polish Academy of Sciences, 51/55 Twarda Street, 00-818 Warsaw, (2)Department of General
Biology and Parasitology, Warsaw Medical University, 5 Chalubinskiego Street, 02-004 Warsaw, Poland; (3)Laboratori de Parasitologia,
Departamento de Microbiologia i Parasitologia Sanitaries, Facultat de Farmacia, Universitat de Barcelona, Av. Joan XXIII sn,
08028 Barcelona, Spain; (4)Laboratoire de Bioecologie Animale, Departement des Sciences de la Vie, Faculte des Sciences de Sfax,
3018 Sfax, Tunisia; (5)Department of Biological Sciences, State University of New York at Albany, Albany, N.Y. 12222, U.S.A.
*Corresponding author: z.swider@twarda.pan.pl
ABSTRACT
The first description of vitellogenesis in the Trypanorhyncha is presented in this paper. Though the type of vitellogenesis and
mature vitellocyte in Dollfusiella spinulifera appear to be unique among the Eucestoda, to some extent they resemble that
observed in the lower cestodes, namely the Tetraphyllidea and Pseudophyllidea. Maturation is characterized by: (1) an increase
in cell volume; (2) extensive development of large, parallel, frequently concentric cisternae of GER that produce proteinaceous
granules; (3) development of Golgi complexes engaged in packaging this material; (4) continuous enlargement of proteinaceous
granules within vesicles and their transformation into shell globule clusters; and (5) progressive fusion of all vesicles, with flocculent
material containing the proteinaceous granules and shell globule clusters, into a single very large vesicle that characterises
mature vitellocytes of this tapeworm. Cell inclusions in and around the large vesicle consist of flocculent material of a very
low density, a few shell globule clusters, moderately dense proteinaceous granules and numerous large droplets of unsaturated
lipids. A new previously unreported mode of transformation of proteinaceous granules into shell globule clusters, that evidently
differs from that of pseudophyllideans and tetraphyllideans, is described. Cytochemical staining with periodic acidthiosemicarbazide-silver proteinate for polysaccharides indicates a strongly positive reaction for membrane-bound glycoproteins
in all membranous structures such as GER, mitochondria, Golgi complexes, nuclear and cell plasma membranes. Similar
staining revealed beta-glycogen particles scattered in the cytoplasm of maturing vitellocytes. Typical cytoplasmic beta-glycogen particles
appear mainly during early vitellocyte maturation but it is characteristic for this species that they are only seldom visible
in mature cells. Some working hypotheses concerning the interrelationship between this particular pattern of vitellogenesis,
possible mode of egg formation in D. spinulifera, its embryonic development and trypanorhynchean life cycle, are drawn
and discussed.
KEY WORDS: Trypanorhyncha, Dollfusiella spinulifera, vitellogenesis, ultrastructure, cytochemistry, proteinaceous shell granules, shell globule
clusters, unsaturated lipids, membrane-bound glycoproteins, beta-glycogen