Open Access
ARTICLE
The actin filament network associated to Sertoli cell ectoplasmic specializations
JUAN CARLOS CAVICCHIA1*, MABEL FÓSCOLO1 , JORGE IBAÑEZ1, CHRISTOPHER LILLIG2, FRANCISCO CAPANI3
1. Instituto de Histología y Embriología “Dr. Mario H. Burgos” (IHEM-CONICET), Facultad de Ciencias Médicas, Universidad
Nacional de Cuyo, Mendoza, Argentina.
2. Institute for Clinical Cytobiology and Cytopathology, Faculty of Medicine, Phillips-Universität Marburg, Germany.
3. Instituto de Investigaciones Cardiológicas “Prof. Dr. Alberto C Taquini” (ININCA), Facultad de Medicina, Universidad
de Buenos Aires and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
* Address correspondence to: Juan Carlos CAVICCHIA. Instituto de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, UNCuyo, Mendoza, Argentina. E-mail: .
BIOCELL 2011, 35(3), 81-90. https://doi.org/10.32604/biocell.2011.35.081
Abstract
Junctional devices in Sertoli cells conform the blood-testis barrier and play a key role in
maturation and differentiation of germ cells. The spacial distribution of ectoplasmic specializations of Sertoli
cells was studied by β-actin immunolabelling, using laser confocal and transmission electron microscopy. For
confocal microscopy, β-actin immunolabelling of ectoplasmic specializations was studied over the background of either prosaposin or glutaredoxin immunolabelling of the Sertoli cytoplasm. Labelling was found
near the basal lamina, surrounding early spermatocytes (presumably in leptotene-zygotene) or at one of two
levels in the seminiferous epithelium: (1) around deep infoldings of the Sertoli cell cytoplasm, in tubular
stages before spermiation, and (2) in the superficial part of the seminiferous epithelium, in tubular stages
after or during spermiation. For transmission electron microscopy, β-actin immunolabelling of ectoplasmic
specializations was also used. Ectoplasmic specializations were found at two different levels of the seminiferous epithelium. We also used freeze fracture to analyze the characteristics of tubulo-bulbar complexes, a
known component of apical ectoplasmic specializations. Also, these different approaches allowed us to study
the complex arrangement of the actin cytoskeleton of Sertoli cells branches, which surround germ cells in
different stages of the spermatogenic cycle. Our results show a consistent labelling for β-actin before, during
and after the release of spermatozoa in the tubular lumen (spermiation) suggesting a significant role of the
actin network in spermatic cell differentiation. In conclusion, significant interrelations among the β-actin
network, the junctional complexes of the blood-testis barrier and the ectoplasmic specializations were detected at different stages of the seminiferous cycle.
Keywords
Cite This Article
CAVICCHIA, J. C., FÓSCOLO, M., LILLIG, C., CAPANI, F. (2011). The actin filament network associated to Sertoli cell ectoplasmic specializations.
BIOCELL, 35(3), 81–90. https://doi.org/10.32604/biocell.2011.35.081