During pubertal development of the testes, germ cells pass initially through the complete succession of spermatogenic differentiation. Using the golden hamster as a model, this volume presents a comprehensive analysis of that establishing period of mammalian spermatogenesis. Detailed morphological and cell kinetic data of the pubertal seminiferous epithelium reveal a level of cellular organization and synchronization coming near to the adult situation. Characteristic, temporarily occurring perturbations of spermatogenic progression are related to specific delays of Sertoli or Leydig cell maturation, respectively. These results emphasize and specify the close structural and functional interdependence of germ and somatic cell development.
Inhalt
1 Introduction.- 1.1 Fetal and Prepubertal Development of the Testis.- 1.2 Adult Spermatogenesis.- 1.3 Pubertal Establishment of Spermatogenesis.- 2 Material and Methods.- 2.1 Animals.- 2.2 Histology.- 2.3 Immunohistochemistry.- 2.4 Enzyme Histochemistry.- 3 Results.- 3.1 Adult Seminiferous Epithelium.- 3.2 Developmental Steps of the Pubertal Seminiferous Epithelium.- 3.2.1 Terminology.- 3.2.2 Sequence of Appearance.- 3.2.3 Synchronization of Germ Cell Development.- 3.2.4 Temporal Appearance.- 3.2.4.1 Duration of Initial Spermatogenesis.- 3.2.4.2 Intratesticular Variance.- 3.2.5 Spatial Arrangement.- 3.3 Developmental Delay of Spermiogenesis.- 3.3.1 Temporal Occurrence.- 3.3.2 Morphology.- 3.3.3 Irregular Germ Cell Associations.- 3.4 11?-Hydroxysteroid Dehydrogenase in Pubertal Leydig Cells.- 3.4.1 Histology of Leydig Cells.- 3.4.2 Demonstration of 11?-Hydroxysteroid Dehydrogenase.- 3.5 Formation of the Sertoli Cell Barrier.- 3.5.1 Morphology.- 3.5.2 Permeability to Lanthanum.- 3.5.3 Synchronization with Germ Cell Development.- 3.6 Degeneration of Germ Cells.- 3.6.1 Apoptosis.- 3.6.2 Spermatocytes.- 3.6.3 Arrested Mitoses.- 3.6.3.1 Morphology.- 3.6.3.2 Formation and Degenerative Fate.- 3.6.3.3 Spatial and Temporal Appearance.- 3.6.3.4 Contact to Lanthanum.- 3.6.4 Spermatids.- 3.7 Clonal Mode of Germ Cell Proliferation.- 3.8 Proliferative Activity of the Adult Seminiferous Epithelium.- 3.9 Proliferative Activity of the Pubertal Seminiferous Epithelium.- 3.9.1 Germ Cells.- 3.9.2 Sertoli Cells.- 4 Discussion.- 4.1 Considerations on the Species and on Methodical Procedures.- 4.2 Developmental Dynamics of the Seminiferous Epithelium.- 4.3 Germ Cell Development.- 4.3.1 Relation to Adult Spermatogenesis.- 4.3.2 Pattern of Synchronization.- 4.3.2.1 Vertical Synchronization.- 4.3.2.2 Horizontal Synchronization.- 4.3.3 Variance.- 4.4 Germ Cell Proliferation.- 4.5 Delayed Spermatid Maturation and 11?-Hydroxysteroid Dehydrogenase Activity in Leydig Cells.- 4.5.1 Desynchronization of Germ Cell Generations.- 4.5.2 11?-Hydroxysteroid Dehydrogenase in Leydig Cells.- 4.5.2.1 Testosterone Dependency of Spermatid Elongation.- 4.5.2.2 Significance of 11 ?-Hydroxysteroid Dehydrogenase for Testosterone Production and Spermiogenesis.- 4.6 Degenerative Phenomena of the Pubertal Seminiferous Epithelium.- 4.6.1 Degeneration of Spermatids.- 4.6.2 Arrested Germ Cell Mitoses.- 4.7 Maturation of Sertoli Cells and Germ Cell Development.- 4.7.1 Sertoli Cell Barrier.- 4.7.2 Sertoli Cell Proliferation.- 4.8 Conclusions.- 5 Summary.- References.