Spermiogenesis and spermatozoa ultrastructure ofAonides oxycephala(Annelida: Spionidae) from the Sea of Japan
| Autor: | Olga V. Yurchenko, Vasily I. Radashevsky, Yana N. Alexandrova |
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| Rok vydání: | 2011 |
| Předmět: | |
| Zdroj: | Invertebrate Reproduction & Development. 55:168-174 |
| ISSN: | 2157-0272 0792-4259 |
| DOI: | 10.1080/07924259.2011.553410 |
| Popis: | Adults of Aonides oxycephala, common inhabitants of shallow boreal waters in the Atlantic and Pacific Oceans, release gametes into the water where fertilization and lecithotrophic larval development occur. During spermiogenesis, the acrosomal vesicle migrates from the posterior to the anterior end of the spermatid and the number of mitochondria reduces from six in early spermatids to four in mature spermatozoa. Each spermatozoon has an ovoid head with the acrosome 1.4 ± 0.1 µm long and 1.6 ± 0.1 µm wide and the nucleus 1.7 ± 0.1 µm long and 2.3 ± 0.1 µm in diameter, four spherical mitochondria, two centrioles oriented perpendicular to each other, putative glycogen in the shape of dense granules in the midpiece, and a flagellum with 9 × 2 + 2 organization of microtubules. The acrosome is a complex heterogeneous structure with five ordered layers of different electron densities, lying in a shallow depression on the anterior end of the nucleus. The nucleus is barrel-shaped (truncated ovoid) with the centriol... |
| Databáze: | OpenAIRE |
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