Segregation of secretory material in all elements of the Golgi apparatus in principal epithellal cells of the rat seminal vesicle

Abstract

At the apex of the epithelial principal cells of the seminal vesicle, there appears to be two types of mature secretory granules, i.e., large and small. Both types of secretory granules showed an eccentric electron-dense spherical body with one pole attached to the delimiting membrane. The remainder of the large granule surrounding the eccentric body showed a granulofilamentous texture, whereas that of the small granule was electron lucent. The formation of these two types of granules was traced back to the various elements of the Golgi stacks. In the case of the large granules, the earliest stage of segregation of the precursor of the eccentric dense body was observed in distensions of the cis-element. Within distensions of all subjacent saccules, the dense bodies continued to be present but progressively increased in size while remaining attached to the saccular membrane. Following separation from the trans-face of the stack, the large prosecretory granules continued to increase in size by fusing with each other. The very large prosecretory granules, as they migrated toward the cell apex to become mature secretory granules, reduced in size prior to exocytosis. The small granules formed exclusively on the trans-aspect of the Golgi stacks and did not appear to fuse with each other. Observations on the formation of the large prosecretory granules within the Golgi apparatus and of the eccentric body in particular, which may be taken as a marker of the saccular membrane, were suggestive of a cis-trans migration and renewal of Golgi saccules.

Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 2: Changes in spermatid organelles associated with development of spermatozoa

“…The Golgi apparatus of spermatids has been examined extensively over the past 60 years and is involved in formation of the acrosome (Figs. 1 and 2) (Burgos and Fawcett, 1955;Burgos and Gutierrez, 1986;Clermont et al, 1981Clermont et al, , 1990Clermont et al, , 1992Clermont et al, , 1993Hermo et al, 1980;Mollenhauer et al, 1976;Susi et al, 1971;Tang et al, 1982). It is composed of compact and noncompact zones.…”

“…However, during spermiogenesis it will undergo very dramatic changes unlike anything seen in other cells of the body (Clermont et al, 1992(Clermont et al, , 1993Hermo et al, 1994;Toshimori et al, 2001). ER cisternae are intimately associated with various organelles and undergo specific modifications in shape.…”

Regulation of secretory granule size by the precise generation and fusion of unit granules

“…Morphological evidence has indicated that progranules, the smallest of which in some cells have volumes 1-2 orders of magnitude smaller than that of their respective mature secretory granules (Fig. 1), can fuse to form structures which have been termed by various authors 'condensing vacuoles' or 'immature granules' [12][13][14][15][16][17][18]. Further modifications create the mature secretory granule [6,7,[19][20][21].…”

Cell Polarity 1

“…sorting steps (Alfalah et al 2005;Clermont et al 1992;Yano et al 2005;Emr et al 2009). Interestingly, some apical proteins bypass the Golgi (Tveit et al 2009).…”