Modulation of beta actin filament network associated to Sertoli ectoplasmic specializations along the rat seminiferous cycle

CAVICCHIA J. C .; FÓSCOLO MABEL; IBAÑEZ J.E.; DÁVILA, J.; CAPANI, F.

Mendoza

Congreso; XXVIII Annual Scientific Meeting. Cuyo Biology Society; 2010

Cuyo Biology Society

Modulation of beta actin filament network associated to Sertoli ectoplasmic speciali-zations along the rat seminiferous cycle  Cavicchia JC, Fóscolo MR, Ibañez JE, Dávila JD, Capani F. Univ Nac Cuyo, 5500 Mendoza. The term blood-testis barrier (BTB) originated by early physiological studies on the mammalian testis that demonstrated a differential transport of ions and metabolites between the basal areas of the seminiferous tubules (basal compartment), and the apical sectors (adluminal one). Its morphological correlate was found to be located in specialized junctional devises found between the adjacent Sertoli (sustentacular) cells, integrated by occluding or tight junctions which seal each inter-Sertoli space and by adherens junctions made up by a highly organized circumferential belt of β actin filaments close to Sertoli cell membranes. Another junctional device, the tubular bulbar complexes (TB) completes this arrangement. These structures were termed ectoplasmic specializations by L. Russell. The aim of this study was to evaluate the distribution and arrangement of β actin and the Sertoli membranes using confocal or electron microscopy, colocalization of beta actin with prosaposin (mainly  stains Sertoli cell cytoplasm) or glutaredoxine ( mainly found in the cytoplasm of elongated spermatids) and freeze fracture (to observe Sertoli cell membranes and TB complexes). A clear, differential spatial organization of βactin filaments together with the arrangement of TB during the spermatic cycle was observed.  In conclusion, significant interrelations between the actin network, the junctional complexes of BTB and TB complexes were detected at different stages of the seminiferous cycle. Supported by Univ. Nac. Cuyo.