Ultrastructure and development of Nosema podocotyloidis n. sp. (Microsporidia), a hyperparasite of Podocotyloides magnatestis (Trematoda), a parasite of Parapristipoma octolineatum (Teleostei).
Bottom Line: The polaroplast is divided into two regions: an outer electron-dense cup with granular content and lacking lamellae and an internal region, less electron-dense, composed of irregularly arranged sacs.The posterior vacuole, with an amorphous electron-dense content, is present.The new species is compared with other species of Nosema from trematodes.
Affiliation: Université Cheikh Anta Diop de Dakar, Laboratoire de Parasitologie, Faculté des Sciences et Techniques, BP 5055, Dakar, République du Sénégal.Show MeSH
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Mentions: The young sporoblasts were ovoid cells with one central diplokaryon (Fig. 3A). They were bounded by an electron-dense coat with a thickness of approximately 30 nm. The electron-lucent vesicles of the cytoplasm increased in number and the endoplasmic reticulum became more distinct. The older sporoblasts were irregular or elongate (Fig. 3C) and their cytoplasm was full of ribosomes and lamellae of endoplasmic reticulum. The diplokaryon was less electron-dense than the cytoplasm. Distinct nucleoli were occasionally seen (Fig. 3C). The sporogenesis began with the development of a polar tube (Fig. 3B, C). Cross-sections of the immature polar tube appeared as symmetrical rings, each with an electron-dense central axis surrounded by a layer of electron-lucent material limited by a membrane (Fig. 3C). The diameter of the immature polar tube was approximately 80–120 nm. In the posterior end of some older sporoblasts, a prominent Golgi apparatus developed near the polar tube (Fig. 3B, C). Its structure was of traditional type. The polaroplast was the last spore structure formed and consisted of highly electron-dense bands (Fig. 3D). At this time, the formation of the endospore wall began. The young spores were diplokaryotic (Fig. 3D).Figure 3.
Affiliation: Université Cheikh Anta Diop de Dakar, Laboratoire de Parasitologie, Faculté des Sciences et Techniques, BP 5055, Dakar, République du Sénégal.