The penial sheath of Pomacea canaliculata (Ampullariidae). II. Proximal and distal glands.

GIRAUD BILLOUD, MAXIMILIANO; GAMARRA-LUQUES, CARLOS; CASTRO-VAZQUEZ, ALFREDO

Córdoba

Congreso; XXV Reunión Científica Anual de la Sociedad de Biología de Cuyo.; 2007

Sociedad de Biología de Cuyo

The proximal and distal glands are serial sets of mucosal plies, located on the dorsal aspect of the penial sheath. The proximal gland is located deep in the sheath’s groove, while the distal one is located near the sheath’s tip. Secretory ducts are absent in both glands. The surface mucosa is composed by a cylindrical epithelium crowned with branched microvilli, and with intermingled goblet mucous cells. Abundant mitochondria occur in the two basal thirds of cylindrical cells, whereas their apical region is full of vesicles. Cells with nuclei showing heavy chromatin clumps attached to the nuclear membrane, and cytoplasmic extensions (devoid of organelles), are placed underneath the surface epithelium and demarcate a labyrinth of extracellular spaces. Even deeper, epithelial “columns” are found, perpendicularly oriented to the surface mucosa. Their epithelial cells bear large granules which appear to contain lipids and proteins. Hollow spaces are found within these columns, reminding the pseudofollicles of the vertebrate adenohypophysis. The complex structures of these glands defy our comprehension of their proposed paracrine (or endocrine?) role on trophism of the male system.