title: Echinococcus multilocularis Leuckart, 1863 (Taeniidae): new data on sperm ultrastructure.
abstract: The present study establishes the ultrastructural organisation of the mature spermatozoon of Echinococcus multilocularis, which is essential for future research on the location of specific proteins involved in the sperm development in this species and also in Echinococcus granulosus. Thus, the ultrastructural characteristics of the sperm cell are described by means of transmission electron microscopy. The spermatozoon of E. multilocularis is a filiform cell, which is tapered at both extremities and lacks mitochondria. It exhibits all the characteristics of type VII spermatozoon of tapeworms, namely a single axoneme, crested bodies, spiralled cortical microtubules and nucleus, a periaxonemal sheath and intracytoplasmic walls. Other characteristics observed in the male gamete are the presence of a >900-nm long apical cone in its anterior extremity and only the axoneme in its posterior extremity. The ultrastructural characters of the spermatozoon of E. multilocularis are compared with those of other cestodes studied to date, with particular emphasis on representatives of the genus Taenia. The most interesting finding concerns the presence of two helical crested bodies in E. multilocularis while in the studied species of Taenia, there is only one crested body. Future ultrastructural studies of other species of the genus Echinococcus would be of particular interest in order to confirm whether or not the presence of two crested bodies is a characteristic of this genus.
authors.affiliation: Laboratori de Parasitologia, Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII, sn, 08028, Barcelona, Spain. jordimiquel@ub.edu.|Facultat de Biologia, Institut de Recerca de la Biodiversitat, Universitat de Barcelona, Av. Diagonal, 645, 08028, Barcelona, Spain. jordimiquel@ub.edu.
authors.forename: Jordi
authors.initials: J
authors.lastname: Miquel
authors.affiliation: W. Stefański Institute of Parasitology, Polish Academy of Sciences, 51/55 Twarda Street, 00-818, Warszawa, Poland.
authors.forename: Zdzisław
authors.initials: Z
authors.lastname: Świderski
authors.affiliation: Faculté de Pharmacie, Laboratoire de Parasitologie et Mycologie Médicale, Université Claude Bernard-Lyon 1, 8 Av. Rockefeller, 69373, Lyon Cedex 08, France.
authors.forename: Samira
authors.initials: S
authors.lastname: Azzouz-Maache
authors.affiliation: Faculté de Pharmacie, Laboratoire de Parasitologie et Mycologie Médicale, Université Claude Bernard-Lyon 1, 8 Av. Rockefeller, 69373, Lyon Cedex 08, France.
authors.forename: Anne-Françoise
authors.initials: AF
authors.lastname: Pétavy
mesh_terms: D000818:Animals; D054468:Axoneme / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure; D002589:Cestoda / Q000166:cytology; D002590:Cestode Infections / Q000469:parasitology; D048209:Echinococcus granulosus / Q000166:cytology*; D048210:Echinococcus multilocularis / Q000166:cytology*; D008297:Male; D046529:Microscopy, Electron, Transmission; D008870:Microtubules / Q000648:ultrastructure; D008928:Mitochondria / Q000502:physiology; D013091:Spermatogenesis / Q000502:physiology; D013094:Spermatozoa / Q000166:cytology / Q000648:ultrastructure*; D013621:Taenia / Q000166:cytology*
keywords: Cestoda; Echinococcus multilocularis; Spermatozoon; Taeniidae; Ultrastructure