SPERMIOGENESIS AND SPERMATOZOON OF ECHINOSTOMA-CAPRONI (PLATYHELMINTHES, DIGENEA) - TRANSMISSION AND SCANNING ELECTRON-MICROSCOPY, AND TUBULIN IMMUNOCYTOCHEMISTRY

Citation
C. Iomini et Jl. Justine, SPERMIOGENESIS AND SPERMATOZOON OF ECHINOSTOMA-CAPRONI (PLATYHELMINTHES, DIGENEA) - TRANSMISSION AND SCANNING ELECTRON-MICROSCOPY, AND TUBULIN IMMUNOCYTOCHEMISTRY, Tissue & cell, 29(1), 1997, pp. 107-118
Citations number
45
Categorie Soggetti
Cell Biology
Journal title
ISSN journal
00408166
Volume
29
Issue
1
Year of publication
1997
Pages
107 - 118
Database
ISI
SICI code
0040-8166(1997)29:1<107:SASOE(>2.0.ZU;2-K
Abstract
Spermiogenesis and the spermatozoon of Echinostoma caproni (from exper imentally infested laboratory mice) were investigated by several metho ds. Transmission electron microscopy shows that spermiogenesis consist s of a proximo-distal fusion of three processes followed by elongation of the spermatid. Scanning electron microscopy shows that the spermat ozoon is a filiform cell, 235 mu m in length, with a cylindrical anter ior extremity and a broader posterior extremity. Epifluorescence micro scopy, including immunocytochemistry of tubulin and labelling of nucle us with specific dyes, has provided valuable additional information. M igration of the nuclei from the common cytoplasmic mass of spermatids to the distal part of the elongating spermatids is visualized, and cen trioles demonstrated in the proximal, anterior region, and the nucleus in the distal, posterior region of the spermatozoon. One axoneme has a distal extremity which in the mature spermatozoon extends 30 mu m mo re distally than the other, with the result that the posterior part of the spermatozoon contains a single axoneme and the nucleus. Immunocyt ochemistry experiments show that a region, 15 mu m in length, not labe lled by the anti-tubulin antibodies with certain fixation-permeabiliza tion procedures, corresponds to a region which, by transmission electr on microscopy, shows external ornamentation on the membrane. This regi on has a bilaterally asymmetric pattern (in TEM), forms angles or coil s according to the fixation used, and marks the boundary between two d istinct patterns of movement. Spermiogenesis and the spermatozoon in E . caproni correspond to the general pattern found in the digeneans, wi th the exception of this asymmetric region. It is emphasized that the use of various methods provides a better understanding of sperm struct ure than transmission electron microscopy alone, particularly in the c ase of long, filiform spermatozoa.