Androgens act to stimulate spermatogenesis through androgen receptors (ARs) on the Sertoli cells and peritubular myoid cells. Specific ablation of the AR in either cell type will cause a severe disruption of spermatogenesis. To determine whether androgens can stimulate spermatogenesis through direct action on the peritubular myoid cells alone or whether action on the Sertoli cells is essential,...

The immunohistochemical localization of actin, vimentin and tubulin in adult ovine and bovine seminiferous tubules was studied at both the light and electron microscopical levels, using an improved methodical protocol. alpha-smooth muscle actin and structural F-actin were found to be present in myoid peritubular cells. Structural F-actin also occurs in Sertoli cells at three localizations; 1) A...

Myasthenia gravis (MG) is an autoimmune disease targeting the skeletal muscle acetylcholine receptor (AChR). Although the autoantigen is present in the thymus, it is not tolerated in MG patients. In addition, the nature of the cell bearing the autoantigen is controversial. To approach these questions, we used two lineages of transgenic mice in which the beta-galactosidase (beta-gal) gene is und...

The renewal of protein in retinal rods and cones has been analyzed by quantitative electron microscope radioautography in adult frogs injected with a mixture of radioactive amino acids. Protein synthesis occurs predominantly in the ergastoplasm, localized in the myoid region of the photoreceptor cells. Much of the newly formed protein next flows through the Golgi complex. In rods, a large propo...

Pseudomyogenic (epithelioid sarcoma-like) hemangioendothelioma is a rare, low grade vascular (endothelial) neoplasm typically presenting as multicentric, superficial to deep nodules in extremities with a slight tendency of affecting young adult males. We report a case of pseudomyogenic hemangioendothelioma in a 15-year-old boy presenting initially with a 1 cm right thigh painless cutaneous lump...

The origin of somatic cell lineages during testicular development is controversial in mammals. Employing basal amphibian tetrapod Xenopus tropicalis we established a cell culture derived from testes of juvenile male. Expression analysis showed transcription of some pluripotency genes and Sertoli cell, peritubular myoid cell and mesenchymal cell markers. Transcription of germline-specific genes ...

We studied retinal photoreceptors of Rana pipiens by using techniques designed to investigate calcium localization. Particularly useful were methods in which intracellular sites of calcium uptake were detected by incubation of saponin-treated isolated retinas in calcium-containing media, with oxalate present as a trapping agent. With these procedures, cell compartments accumulate deposits, whic...

Myopericytoma (MPC) is a rare kind of benign neoplasm, showing derivation from perivascular myoid cells. About 115 cases have been reported in the English literature; however, most of the literature focuses on the description and classification of pathology. The case presented here is that of a 42-year-old woman with a surgical management experience of multicentric MPC in the maxillofacial regi...

Self-renewal and differentiation of spermatogonial stem cells (SSCs) provide the foundation for testis homeostasis, yet mechanisms that control their functions in mammals are poorly defined. We used microarray transcript profiling to identify specific genes whose expressions are augmented in the SSC-enriched Thy1(+) germ cell fraction of mouse pup testes. Comparisons of gene expression in the T...