Light and Transmission Electron Microscopy of Two Spermatogenic Pathways and Unimorphic Spermatozoa inVenustaconcha ellipsiformis(Conrad, 1836) (Bivalvia: Unionoida)
| Autor: | Walter R. Hoeh, William H. Heard, Sally Shepardson, Sophie Breton |
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| Rok vydání: | 2012 |
| Předmět: |
Genetics
Unionoida endocrine system urogenital system Biology Unionidae biology.organism_classification Sertoli cell Cell biology medicine.anatomical_structure Meiosis Ultrastructure medicine Animal Science and Zoology Vitellogenesis Mitosis Spermatogenesis reproductive and urinary physiology Ecology Evolution Behavior and Systematics |
| Zdroj: | Malacologia. 55:263-284 |
| ISSN: | 0076-2997 |
| DOI: | 10.4002/040.055.0207 |
| Popis: | This study followed the typical and atypical pathways of spermatogenesis in Venustaconcha ellipsiformis (Conrad, 1836) (Bivalvia: Unionoida: Unionidae), during an entire year and documents the developmental stages of both using light and transmission electron microscopy. The spermatozoa produced by both pathways were essentially morphologically identical and contained a single acrosomal vesicle. Production of spermatozoa in the two pathways overlapped from May to October, and vitellogenic eggs were present over this same time period. Atypical spermatogenesis also occurred from November through April. The typical pathway involved the mitotic and meiotic divisions that include spermatogonial cells, primary and secondary spermatocytes, spermatids and mature spermatozoa. In contrast, atypical spermatozoa appeared to be produced in a pathway that included spermatozoa morulae and spermatids produced from spermatogonial cells located in Sertoli cells. Large amorphous inclusions (Al) observed in Sertoli ... |
| Databáze: | OpenAIRE |
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