title: Mesocestoides lineatus (Goeze, 1782) (Mesocestoididae): new data on sperm ultrastructure.
abstract: Spermiogenesis and the ultrastructural characters of the spermatozoon of Mesocestoides lineatus are described by means of transmission electron microscopy, including cytochemical analysis for glycogen. Materials were obtained from a golden hamster (Mesocricetus auratus) after experimental infection with tetrathyridia metacestodes obtained from naturally infected lizards (Anolis carolinensis) from Louisiana. Spermiogenesis in M. lineatus is characterized by the orthogonal growth of a free flagellum, a flagellar rotation, and a proximodistal fusion. The zone of differentiation contains 2 centrioles associated with striated rootlets and a reduced intercentriolar body. The mature spermatozoon of M. lineatus lacks a mitochondrion, and it is characterized by the presence of (1) a single, spiraled, crested body 150 nm thick; (2) a single axoneme of the 9+'1' pattern of trepaxonematan Platyhelminthes; (3) a parallel and reduced row of submembranous cortical microtubules; (4) a spiraled cordon of glycogen granules; and (5) a spiraled nucleus encircling the axoneme.
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
authors.forename: Jordi
authors.initials: J
authors.lastname: Miquel
authors.forename: Catarina
authors.initials: C
authors.lastname: Eira
authors.forename: Zdzisław
authors.initials: Z
authors.lastname: Swiderski
authors.forename: David Bruce
authors.initials: DB
authors.lastname: Conn
mesh_terms: D000818:Animals; D002590:Cestode Infections / Q000469:parasitology / Q000662:veterinary; D006224:Cricetinae; D008116:Lizards / Q000469:parasitology*; D008297:Male; D008645:Mesocestoides / Q000502:physiology / Q000648:ultrastructure*; D008647:Mesocricetus; D046529:Microscopy, Electron, Transmission / Q000662:veterinary; D013091:Spermatogenesis; D013094:Spermatozoa / Q000648:ultrastructure*