Analysis of nucleolar components by combined silver staining and serial sections procedures

Abstract The nucleolus in Sertoli cells, spermatogonia and spermatocytes of rabbit testis was studied under electron microscopy using a silver staining method in combination with serial section reconstruction. Fibrillar centers (Fc) as part of the nucleolar organizer region (NOR) are usually observed in these nucleoli and appear poorly stained after silver method which stain nucleolar acidic pr o teins. Silver stains preferentially part of the dense fibrillar components of the nucleolus which appears like strings inside the nucleolar mass emerging from part of the fibrillar center. The quantity and extent of the silver reaction seems to be correlated to the degree of transcriptional activity of each type of nucleolus. Moreover, the methods used allow the topography of the different nucleolar components to be inferred.