Spermiogenesis and spermatozoa in Acanthodasys aculeatus (Gastrotricha, Macrodasyida): an ultrastructural study
Articolo
Data di Pubblicazione:
2003
Citazione:
Spermiogenesis and spermatozoa in Acanthodasys aculeatus (Gastrotricha, Macrodasyida): an ultrastructural study / L. Guidi, M. Ferraguti, L. Pierboni, M. Balsamo. - In: ACTA ZOOLOGICA. - ISSN 0001-7272. - 84:1(2003), pp. 77-85.
Abstract:
The spermatogenesis, the spermiogenetic process and the structure of the
mature spermatozoon of Acanthodasys aculeatus
(Gastrotricha, Macrodasyida) are described from an ultrastructural point of view. Several spermatogonia in mitotic divisions were seen, proving that euthely of gastrotrichs does not concern gonads. Spermiogenesis is characterized by the early formation of both the acrosome and the axoneme, by the subsequent appearances of a
perinuclear helix and of a complex axial tubular structure in the acrosome and
by the late development of the peraxonemal striated cylinder. The mature spermatozoon is filiform, and composed of a spiralized acrosome, a helical nuclear–mitochondrial complex and a long flagellum. The acrosome contains an axial tubular structure and the spring-shaped nucleus delimits a single, long
mitochondrion. A perinuclear helix formed by the pro-acrosome surrounds the nuclear–mitochondrial complex extending for its whole length. A monolayered, obliquely striated cylinder encloses the 9 x 2 + 2 axoneme; its terminal part is empty because of the shortness of the axoneme.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Acanthodasys aculeatus ; Gastrotricha ; spermatozoa ; spermiogenesis ; ultrastructure
Elenco autori:
L. Guidi, M. Ferraguti, L. Pierboni, M. Balsamo
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