Description
The spermatogenesis and spermatozoa of mammals are of funda mental interest to a wide variety of academic and scientific disci plines; zoologists keep up interest in comparative biology of sper matogenesis and spermatozoa in different groups of mammals for determining their phylogenetic interrelationships. Therefore, during the past 15 years, a wealth of reviews and papers have been published on the morphology (including ultrastructure), histochemistry, auto radiography, biochemistry (including immunology), and cell physiol ogy of the seminiferous epithelium including Sertoli cells, spermato genesis and spermatozoa in mammals. Hormonal regulation of sper matogenesis also forms the subject to numerous studies. Research in this area of reproductive biology continues at a remarkable rate, and new and significant information appears daily in a wide range of journals, published symposia, and specialist reviews. The scattered nature of this information makes it difficult for a scientist, student or andrologist to go through even a small fraction of these publications on the biology of spermatogenesis and spermatozoa and so obtain a general oversight of current activity and new advances. Actually, very little attempt has been made previously to summarize and inte grate the vast information which has become available as a result of use of modern techniques of microscopy, surface topography, histo chemistry, autoradiography, biochemistry, biophysics, immunology, molecular biology, in vitro systems, etc. Much-needed interdisciplin ary approach in biology of seminiferous epithelium, spermatogenesis and spermatozoa is very difficult and thus lacking. One Spermatogenesis.- I Seminiferous Epithelium.- A. Cycle of Seminiferous Epithelium.- B. Wave of Seminiferous Epithelium.- C. Duration of the Cycle of the Seminiferous Epithelium.- D. Coordination of Evolution of Several Superimposed Generations of Germ-Cells.- E. Synchronous Development of Spermatogenic Cells.- F. Sertoli Cells.- 1. Morphology and Blood-Testis Barrier.- 2. Functional Features.- 3. Sertoli Cells and the Hormonal Regulation of Spermatogenesis.- G. In Vitro Studies.- II Spermatogonia.- A. Spermatogonial Types.- B. Stem-cell Renewal and Multiplication of Spermatogonia.- C. Cell-cycle Kinetics and Control of Spermatogonial Multiplication.- D. Spermatogonial Degenerations and Their Sensitivity to Various Factors.- E. Structure, Cytochemistry and Biochemistry of Spermatogonia.- 1. Nucleus.- 2. Nucleic Acids and Protein Synthesis.- 3. Cytoplasmic Organelles and Enzymes.- a) Organelles.- b) Enzymes.- III Spermatocytes.- A. Meiosis and its Regulation.- B. Subcellular and Molecular Aspects of Meiosis.- 1. Nuclear Components.- 2. Changes in Nucleic Acids and Proteins During Meiosis.- a) DNA.- b) Protein and RNA.- 3. Intercellular Bridges and Plasma Membrane.- 4. Cytoplasmic Organelles and Enzymes.- 5. Nuage and Chromatoid Body.- C. Morphology, Cytochemistry and Biochemistry of Secondary Spermatocytes.- IV Spermatids and Spermiogenesis.- A. Development of Spermatid Nucleus.- 1. Chromatin Condensation and Associated Changes in Nucleoproteins.- 2. Nuclear Envelope.- B. Cytoplasmic Components.- 1. Chromatoid Body.- 2. The Golgi Complex and Acrosome (or Acrosomal Cap) Formation.- a) Golgi Complex.- b) Development of Acrosome.- 3. Mitochondria.- 4. Manchette and Shape of the Sperm Head.- 5. Tail.- a) Centrioles and Development of Tail Flagellum (Axoneme).- b) Development of Fibrous Sheath.- c) Mitochondrial Sheath.- d) Chromatoid Body and Annulus.- e) Miscellaneous Components.- f) Malformations of Spermatid Differentiation.- 6. Residual Cytoplasm and Droplets.- a) Residual Cytoplasm and its Organelles.- b) Spermiation.- c) Cytoplasmic Droplet.- d) Differentiations (or Specializations) of Membranes.- V Antigens During Spermatogenesis.- A. Development and Distribution.- B. Functions.- Two Spermatozoa.- VI General Considerations.- VII Head.- A. Shape and Size.- B. Nucleus.- 1. Sex Chromosomes.- 2. Nuclear Chromatin and Vacuoles.- a) Chromatin.- b) Vacuoles.- 3. Nuclear Envelope.- 4. Proteins and Nucleic Acids.- a) Proteins.- b) DNA.- c) RNA.- C. Acrosome.- 1. Structure.- 2. Chemical Components and Their Significance.- a) Carbohydrates, Proteins and Lipids.- b) Enzymes.- c) Hydrolytic Enzymes and Acrosome Reaction.- d) Release of Acrosomal Enzymes Under Experimental Conditions.- e) Acrosome as a Lysosome.- D. Subacrosomal Space.- E. Post-nuclear Cap.- 1. Structure.- 2. Chemistry.- 3. Function.- VIII Neck.- A. Basal Plate and Connecting Piece.- B. Centrioles and Their Relationship with Other Components.- C. Other Elements.- IX Cytoplasmic Droplet.- A. Structure.- B. Chemistry.- C. Function.- X Tail.- A. Axoneme.- 1. Peripheral Fibres (or Doublet Microtubules).- 2. Radial Spokes.- 3. Central Tubules.- 4. Central Sheath.- 5. Structural and Chemical Interactions Between Components of the Axoneme.- B. Mid-piece and Sperm Metabolism.- 1. Dense Fibres.- a) Morphology.- b) Chemistry.- c) Function.- 2. Mitochondria.- a) Morphology.- b) Ultrastructure and Chemistry.- c) Lipids of Spermatozoa and Their Significance.- 3. Metabolic Pathways and Enzymes.- a) Enzymes of Glycolysis.- b) Enzymes of Krebs and Pentose Phosphate Cycles.- c) Phosphatases.- d) Esterases.- e) Hydroxysteroid Dehydrogenases and Effects of Steroids on Spermatozoa.- f) Cyclic Nucleotides and Their Regulatory Enzymes.- g) Release of Enzymes Under Various Experimental Conditions.- C. Annulus.- 1. Morphology.- 2. Origin and Function.- D. Main-piece.- E. End-piece.- XI Plasma Membrane and its Surface Components.- A. Fine Structure.- B. Macromolecular Organization and Physical Properties.- C. Intramembranous Particles.- D. Enzymes.- E. Regional Specializations of Surface Properties.- a) Surface Charge.- b) Antigens.- c) Coating Substances.- d) Lectins as Surface Markers of Spermatozoa.- XII Sperm Motility.- A. Mechanism of Sperm Motility.- B. Energetics of Sperm Motility.- C. Effects of Chemical and Physical Agents on Sperm Motility.- 1. Elements and Ions.- 2. Dilution, Temperature and Osmotic Pressure.- 3. Cyclic AMP, Caffeine, Aminophylline, Theophylline, and Pentoxiphylline.- a) Cyclic AMP.- b) Caffeine.- c) Aminophylline, Theophylline, and Pentoxiphylline.- 4. Kallikrein.- 5. Carnitine and Acetylcarnitine.- 6. Glyceryl Phosphocholine.- 7. Protein Carboxylmethylase.- 8. Epididymal Sperm Motility Factors.- 9. Albumin and Other Macromolecules.- 10. Taurine and Hypotaurine.- 11. Steroids.- 12. Cholinergic System.- 13. Catecholamines and Tranquillizers.- 14. Arginine.- References.
