Accession Number 892HE-0004
Document Delivery 892HE: Document Delivery available
Authors Culioli JL. Foata J. Mori C. Orsini A. Marchand B.

Author e-mail Address jculioli@univ-corse.fr
Title Ultrastructure of spermiogenesis and the spermatozoon in Castrada cristatispina Papi, 1951 (Platyhelminthes, Rhabdocoela, Typhloplanida)
Source Acta Zoologica. 85(4):245-256, 2004 Oct.
Abbreviated Source Acta Zool. 85(4):245-256, 2004 Oct.
Copyright Publisher BLACKWELL PUBLISHING LTD, 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND. URL: http://www.blackwell-science.com

ISSN 0001-7272
Author Keywords Castrada cristatispina. Rhabdocoela. Spermatozoon. Spermiogenesis. Ultrastructure.

KeyWords Plus Intercentriolar body. Temnocephala-novaezealandiae. Phylogenetic implications. Sperm ultrastructure. Mature spermatozoa. Functional-aspects. Including notes. Genital system. Craspedella sp. Plathelminthes.

Abstract Spermiogenesis in Castrada cristatispina begins with the formation of a zone of differentiation containing two centrioles with associated striated rootlets and an intercentriolar body between them. The centrioles give rise to two parallel, free flagella of the Trepaxonemata 9 + '1' pattern, growing out in opposite directions. Spermatids undergo a latero-ventral rotation of the flagella and a subsequent disto-proximal rotation of centrioles, and a distal cytoplasmic projection appears. The former rotation involves the compression of a row of microtubules and allows the recognition of a ventral side and a dorsal side. At the end of the differentiation, the centrioles and cortical microtubules lie parallel to the sperm axis. The modifications of the intercentriolar body and the migration of the nucleus and the centrioles toward the distal projection are described. The mature spermatozoon of C. cristatispina is filiform, tapered at both ends and shares several features with the other Rhabdocoela gametes. Nevertheless, the posterior extremity is capped by an electron-dense material. A gradient between mitochondria and dense bodies exists along the sperm axis. This study has enable us a phylogenetic approach of the Rhabdocoela through a comparison of the ultrastructural features of C. cristatispina with the other Rhabdocoela taxa. We propose the disto-proximal rotation of centrioles as a synapomorphy of the Rhabdocoela. [References: 48]
Language English
Publication Type Article
Subset Current Contents(R)/Agriculture, Biology & Environmental Sciences.
CC Categories Animal Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences.
Entry Week 2005 week 10
Reprint Address Reprint available from: Culioli JL. Univ Corse, Fac Sci & Tech, Lab Modeles Ecol Mediterraneenne, F-20250 Corsica, France, .
Institution Reprint available from:
Culioli JL
Univ Corse, Fac Sci & Tech, Lab Modeles Ecol Mediterraneenne
F-20250 Corsica
France