Non-ciliated Type Research Articles

The ultrastructural features of the infundibulum of the green iguana, Iguana iguana.

The purpose of this study is to describe, in detail, the ultrastructure of the infundibulum of the sexually mature and active female green iguana, Iguana iguana. The infundibulum of five iguanas was remarkably distinct from the uterus, and was also clearly demarcated into cranial (expanded v-shaped) and caudal (tubular) divisions. Tissue samples obtained from five portions (three from the cranial division and two from the caudal division) of the infundibulum were processed conventionally for light and electron microscopy. The epithelial lining of the most anterior, middle, and posterior, parts of the cranial division displayed nonciliated cells predominantly, and occasionally ciliated cells. The numerous secretory granules in nonciliated type 1 cell found in the fimbrial aspect of the infundibulum were homogenous and deeply electron-dense, but those in the other two regions were variants of this cell type because they contained variably electron-dense secretory granules. Two main types of nonciliated cells (type 2 and its variant, type 3, as well as type 4) occurred in the epithelial lining of the caudal division of the infundibulum, but they, clearly, showed no dense secretory granules. Whereas the nonciliated type 2 cell and its variant (type 3 cell) contained large glycogen deposits, the type 4 cell lacked these deposits but its apical part contained large lipid-like droplets and, remarkably, blebbed into the duct lumen. The nonciliated cells lining the mucosal tubular glands contained highly electron-dense secretory granules, which were similar to those found in the nonciliated type 1 cell in the epithelial lining of the fimbrial part of the cranial division of the infundibulum.

Ontogeny of the testicular excurrent duct system of male Japanese quail (Coturnix japonica): A histological, ultrastructural, and histometric study.

The testicular excurrent duct system undergoes several physiological and morphological changes during the reproductive stage or breeding season in mammals, birds, and reptiles. Studies on normal age-related histomorphological changes in the excurrent duct system of Japanese quails (Coturnix japonica) remain unreported, despite the extensive use of this bird as an avian model in research studies. The current study investigated the histological, ultrastructural, and histometric changes in the testicular excurrent duct system of the Japanese quail during three reproductive stages, namely prepubertal, pubertal, and adult. Simple squamous to low cuboidal cells formed the epithelia of the rete testis in prepubertal and pubertal birds, while in adult birds the lining was low cuboidal to cuboidal. In pubertal and adult birds, the nonciliated Type I epithelial cells of the proximal efferent duct displayed a subapical endocytotic apparatus comprising coated pits, coated apical tubules, and endosomes. There was a significant increase (p ≤ .001) in epithelial heights of all ducts of the excurrent duct system in the mature, sexually active, adult birds when compared to the other age groups. The luminal and tubular diameters, and the cross-sectional areas of efferent ducts and the epididymal duct unit increased significantly (p ≤ .001) with age. It is concluded that the morphology and morphometry of the excurrent ducts of the testis of the Japanese quail change as birds mature.

The Excurrent Ducts of the Testis of the Emu (Dromaius novaehollandiae) and Ostrich (Struthio camelus): Microstereology of the Epididymis and Immunohistochemistry of its Cytoskeletal Systems

The volumetric proportion of the various ducts of the epididymis of the emu and ostrich and the immunohistochemistry of actin microfilaments, as well as cytokeratin, desmin and vimentin intermediate filaments, were studied in the various ducts of the epididymis of the emu and ostrich. The volumetric proportions of various ducts, which are remarkably different from those of members of the Galloanserae monophyly, are as follows: the rete testis, 5.2 +/- 1.4% for the emu and 2.4 +/- 1.8% for the ostrich; efferent ducts, 14.2 +/- 2.3% (emu) and 11.8 +/- 1.8% (ostrich); epididymal duct unit, 25.8 +/- 5.8% (emu) and 26.1 +/- 4.1% (ostrich) and connective tissue and its content, 54.7 +/- 5.8% (emu) and 60.0 +/- 4.9% (ostrich). Unlike in mammals and members of the Galloanserae monophyly, only vimentin was immunohistochemically demonstrated in the rete testis epithelium of the emu, and none of the cytoskeletal protein elements in the ostrich rete testis. The epithelium of the efferent ducts of the emu co-expressed actin, cytokeratin and desmin in the non-ciliated type I cells, and vimentin in the ciliated cell component. The ostrich demonstrated only cytokeratin in this epithelium. The ratite epididymal duct unit is different from that of mammals in lacking actin (only weaky expression in the ostrich), desmin and cytokeratin, and a moderate/strong immunoexpression of vimentin in the basal cells and basal parts of the NC type III cell in the epididymal duct unit. Immunoexpression of the microfilaments and intermediate filaments varied between the two ratite birds, as has been demonstrated previously in birds of the Galloanserae monophyly, and in mammals.

The fine structure of the epithelial lining of the ex-current duct system of the testis of the domestic fowl (Gallus domesticus).

Ultrastructurally, at least five different cell types were identified in the genital duct system of the cock, namely (1) low cuboidal cells lining the rete testis, (2) and (3) nonciliated type I and ciliated cells, lining the ductuli efferentes and narrow connecting ductules, (4) non‐ciliated type II cells, lining the wide connecting ductules, ductus epididymidis and ductus deferens, and (5) basal cells found mainly with type II cells.The low cuboidal cells have an imbricated arrangement which, in a tissue section, influences the interpretation of their shape as well as their luminal and basal connections; squamous, cuboidal, and other shapes were observed. They possess a large Golgi complex, many small mitochondria, a few profiles of rough endoplasmic recticulum and electron dense cytoplasmic bodies. The fine structure indicates an active secretory function; the secretion is probably of a protein‐rich type. The cells appear to be capable of taking up spermatozoa from the lumen. There is a rich distribution of nerves in the subepithelial tissue. This could indicate a contractile function of the rete cells; its significance has been discussed.The non‐ciliated type I cells are characterized by the presence of electron‐dense worm‐like structures which are connected to the surface or scattered in the apical cytoplasm. Their luminal border has many microvilli, some of which form stereocilia. There is an abundance of mitochondria and smooth endoplasmic reticulum; these are evidences of metabolic and secretory activities respectively, but the nature of the secretion is unknown. Lysosomal bodies of many types are scattered throughout the cytoplasm of the non‐ciliated type I cell. The worm‐like bodies may be concerned with the uptake from the lumen.The main ultrastructural features of the non‐ciliated type II cells are similar to those of protein secreting cells like the exocrine pancreatic acini and salivary glands. There is an abundance of distended rough and transitional endoplasmic reticulum, a well developed Golgi complex, smooth vesicles and electron‐dense secretory granules in various stages of formation. Mature granules are discharged by the fusion of their membranes with the cell membrane of the secretory surface. There is an intimate association between the membranes limiting the endoplasmic reticulum and those of the mitochondria. Dense vacuolated bodies are present in the cytoplasm which are probably lysosomes. The cytoplasmic fibrillar content of these cells and the rich innervation in the subepithelial tissue suggest a contractile function.The ciliated cells possess a small Golgi complex and many mitochondria, slightly smaller than those of the type I cells and concentrated mainly in the supranuclear region. In view of the presence of motile cilia, and probably the fibrous cytoplasmic bundles, the ciliated cells may function in moving spermatozoa along the excurrent ducts. The cells are non‐secretory but could play a role in the resorption of fluids secreted by the seminiferous tubules in an analogous way to their mammalian counterparts. Electron‐dense, heterogeneous, cytoplasmic bodies occur and are assumed to be lysosomes. Their probable significance pertaining to resorptive functions of the cell has been discussed.The basal cells have a large dense irregular nucleus and a scanty fibrillar cytoplasm containing few organelles. The nature of these cells in relation to early forms of ciliated cells, precursors of holocrine cells, myoepithelia and transitional forms between myoepithelia and true epithelia has been discussed and a role in ejaculation has been suggested.