Modulation of Beta Actin Filament Network along the Rat Seminiferous Epithelium Cycle

A. LOSINNO; L. LÓPEZ; F. CAPANI; M. FÓSCOLO; J. IBAÑEZ; J. CAVICCHIA

Denver

Congreso; 51 th Annual Meeting ASCB 2011; 2011

THE AMERICAN SOCIETY FOR CELL BIOLOGY

Junctional devices in Sertoli cells play a key role in maturation and differentiation of  germ cells. However it is not totally understood the cellular and subcellular organization of these specializations. By combining light and electron microscopic techniques using â-actin with prosaposin and glutaredoxin antibodies (to stain Sertoli cytoplasm) we observed the structural (confocal microscopy) and ultrastructural (electron microscopy) organization of tight and adherent junctions, which are the morphologic substrate of the blood testis barrier (BTB). Beta actin also characterizes ectoplasmic specializations found at different level of the seminiferous epithelium. Actin was quantified (western blot technique) in relation to the spermiation period in different segments of the seminiferous tubules visualized by transillumination under stereomicroscopy. We analyzed by freeze fracture the characteristics of tubular bulbar complexes, a known component of ectoplasmic specializations.All together, these different approaches also allowed us to study the complex arrangement of actin cytoskeleton of Sertoli cells branches, which surround germ cells in different stages of the spermatogenic cycle. Overall, our results show a consistent labelling of â- actin before, during and after the release of spermatozoa in the tubular lumen (spermiation) suggesting a significant role of the actin network in spermatic cells differentiation. In conclusion, significant interrelations among the â-actin network, the junctional complexes of the BTB and the ectoplasmic specializations were detected at different stages of the seminiferous cycle.