AIM: To study the transformation of taeniid spermatozoon during spermatogenesis on the ultrastructure level. METHODS: Transmission electronmicroscopy. RESULTS: This paper was the second part of the ultrastructural observations on the spermatogenesis in Taeniid cestodes: The transformation of the spermatozoon. The 64-spermatid-plasmodium was generated from the secondary meiosis of the 32 rose-like secondary spermatocytes. The transformation of the spermatozoon was a complex process. Firstly, both the cytoplasm and nucleus of the spermatid elongated while the cytoplasm increased and connected to the cytoplasmic mass (cytophore). Secondly, the chromatins of nucleus polymerized to a thread-bundle-like structure. Finally, it detached from the cytoplasm mass and became a mature spermatozoon. The mature spermatozoon was a thread-like structure, about 16.2-18.6 microns in length and 0.35-0.45 micron in diameter. There were two structurally distinct parts: the part with the nucleus was the head and the part without the nucleus was the tail. The head measured about 5-6 microns in length, 1/3 of the total body length and contained an elongated nucleus which twined around the axoneme without mitochondria. The tail was about 11.2-16.6 microns in length. Throughout the core of the tail was an axoneme with typical "9 + 1" structure. The anterior of the tail, just behind the head, were some mitochondria, about 1.6-1.7 microns in total length which twined around the axoneme. The posterior of the tail contained only an axoneme. In cross-section of the spermatozoon, about 46 microtubules were beneath the plasma membrane. CONCLUSION: The transformation of the spermatozoon is a very complex process.
AIM: To study the transformation of taeniid spermatozoon during spermatogenesis on the ultrastructure level. METHODS: Transmission electronmicroscopy. RESULTS: This paper was the second part of the ultrastructural observations on the spermatogenesis in Taeniid cestodes: The transformation of the spermatozoon. The 64-spermatid-plasmodium was generated from the secondary meiosis of the 32 rose-like secondary spermatocytes. The transformation of the spermatozoon was a complex process. Firstly, both the cytoplasm and nucleus of the spermatid elongated while the cytoplasm increased and connected to the cytoplasmic mass (cytophore). Secondly, the chromatins of nucleus polymerized to a thread-bundle-like structure. Finally, it detached from the cytoplasm mass and became a mature spermatozoon. The mature spermatozoon was a thread-like structure, about 16.2-18.6 microns in length and 0.35-0.45 micron in diameter. There were two structurally distinct parts: the part with the nucleus was the head and the part without the nucleus was the tail. The head measured about 5-6 microns in length, 1/3 of the total body length and contained an elongated nucleus which twined around the axoneme without mitochondria. The tail was about 11.2-16.6 microns in length. Throughout the core of the tail was an axoneme with typical "9 + 1" structure. The anterior of the tail, just behind the head, were some mitochondria, about 1.6-1.7 microns in total length which twined around the axoneme. The posterior of the tail contained only an axoneme. In cross-section of the spermatozoon, about 46 microtubules were beneath the plasma membrane. CONCLUSION: The transformation of the spermatozoon is a very complex process.
Authors: Aneta Yoneva; Zdzisław Swiderski; Katia Georgieva; Pavel N Nikolov; Yana Mizinska; Boyko B Georgiev Journal: Parasitol Res Date: 2008-08-27 Impact factor: 2.289