SERTOLI-CELL NUCLEAR-PORE NUMBER CHANGES IN SOME STAGES OF THE SPERMATOGENIC CYCLE OF THE RAT SEMINIFEROUS EPITHELIUM

In an earlier study we described changes in the number and distributio n of nuclear pores during maturation of germ cells at given stages of the spermatogenic cycle; these changes were related to the activity of nucleus-cytoplasm transport, Similarly, the present work was performe d by combining freeze-fracture techniques with Sertoli nuclei identifi cation criteria, using fragments of tubules isolated by transilluminat ion under stereomicroscopy, We studied the density of nuclear pores in freeze-fracture replicas of the Sertoli nuclear envelope a? stages XI II-XIV-I compared with stages IX-XII. Pore counts were carried out on photographs of the platinum replicas using a digitalized morphometric board. The results were statistically analyzed using Student's t test. The difference in density (pore number/mu m(2) +/- SEM) was significa nt between stages IX-XII (8.25 +/- 0.63) and XIII-XIV-I (10.80 +/- 0.6 0). We postulate that this density appears to be increased at the time of increased metabolic requirements of the Sertoli cell.