TY - JOUR
T1 - Spermiogenesis and spermatozoon of Echinostoma caproni (Platyhelminthes, Digenea)
T2 - Transmission and scanning electron microscopy, and tubulin immunocytochemistry
AU - Iomini, C.
AU - Justine, J. L.
N1 - Funding Information:
Pauline Neveu and Catherine Royer helped with some of the immunocytochemical experiments. Dr Annie Fournier and Sandrine Trouv6 (University of Perpignan) provided cercariae of E. caproni. Prof. Barrie G. Jamieson kindly edited the English. The work was funded by the INTAS grant no. 93-2176, 'Ultrastructure and immunocytochemistry of the cytoskeleton of spermatozoa, eggs and fertilization in selected invertebrate species, for the understanding of phylogeny' and a BQR 'Immunocytochimie des spermatozo~des de Plathel-minthes et N6mat0des' from the Mus6um. We acknowledge the help of the Centre Interuniversitaire de Microscopie l~lectronique, Universit6 Paris VII, Paris, France for scanning electron microscopy, and of the service de Microscopie l~lectronique, Laboratoire de Biologie des Invert6br6s Marins et Malacologie, MNHN, Paris, for transmission electron microscopy.
PY - 1997
Y1 - 1997
N2 - Spermiogenesis and the spermatozoon of Echinostoma caproni (from experimentally infested laboratory mice) were investigated by several methods. Transmission electron microscopy shows that spermiogenesis consists of a proximo-distal fusion of three processes followed by elongation of the spermatid. Scanning electron microscopy shows that the spermatozoon is a filiform cell, 235 μm in length, with a cylindrical anterior extremity and a broader posterior extremity. Epifluorescence microscopy, including immunocytochemistry of tubulin and labelling of nucleus with specific dyes, has provided valuable additional information. Migration of the nuclei from the common cytoplasmic mass of spermatids to the distal part of the elongating spermatids is visualized, and centrioles 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 μm more distally than the other, with the result that the posterior part of the spermatozoon contains a single axoneme and the nucleus. Immunocytochemistry experiments show that a region, 15 μm in length, not labelled by the anti-tubulin antibodies with certain fixation-permeabilization procedures, corresponds to a region which, by transmission electron microscopy, shows external ornamentation on the membrane. This region has a bilaterally asymmetric pattern (in TEM), forms angles or coils according to the fixation used, and marks the boundary between two distinct patterns of movement. Spermiogenesis and the spermatozoon in E. caproni correspond to the general pattern found in the digeneans, with the exception of this asymmetric region. It is emphasized that the use of various methods provides a better understanding of sperm structure than transmission electron microscopy alone, particularly in the case of long, filiform spermatozoa.
AB - Spermiogenesis and the spermatozoon of Echinostoma caproni (from experimentally infested laboratory mice) were investigated by several methods. Transmission electron microscopy shows that spermiogenesis consists of a proximo-distal fusion of three processes followed by elongation of the spermatid. Scanning electron microscopy shows that the spermatozoon is a filiform cell, 235 μm in length, with a cylindrical anterior extremity and a broader posterior extremity. Epifluorescence microscopy, including immunocytochemistry of tubulin and labelling of nucleus with specific dyes, has provided valuable additional information. Migration of the nuclei from the common cytoplasmic mass of spermatids to the distal part of the elongating spermatids is visualized, and centrioles 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 μm more distally than the other, with the result that the posterior part of the spermatozoon contains a single axoneme and the nucleus. Immunocytochemistry experiments show that a region, 15 μm in length, not labelled by the anti-tubulin antibodies with certain fixation-permeabilization procedures, corresponds to a region which, by transmission electron microscopy, shows external ornamentation on the membrane. This region has a bilaterally asymmetric pattern (in TEM), forms angles or coils according to the fixation used, and marks the boundary between two distinct patterns of movement. Spermiogenesis and the spermatozoon in E. caproni correspond to the general pattern found in the digeneans, with the exception of this asymmetric region. It is emphasized that the use of various methods provides a better understanding of sperm structure than transmission electron microscopy alone, particularly in the case of long, filiform spermatozoa.
KW - Digenea
KW - Immunocytochemistry
KW - Platyhelminthes
KW - Tubulin
KW - Ultrastructure
UR - http://www.scopus.com/inward/record.url?scp=0031043818&partnerID=8YFLogxK
U2 - 10.1016/S0040-8166(97)80077-8
DO - 10.1016/S0040-8166(97)80077-8
M3 - Article
C2 - 9061981
AN - SCOPUS:0031043818
SN - 0040-8166
VL - 29
SP - 107
EP - 118
JO - Tissue and Cell
JF - Tissue and Cell
IS - 1
ER -