Transmission electron microscopic ultrastructures of the male germinal cells of <i>Fibricola seoulensis</i>

, Sohn, W M; , Lee, S H

doi:1993.31.3.183

Korean J Parasito > Volume 31(3):1993 > Article

Original Article


Korean J Parasitol. 1993 Sep;31(3):183-191. English. Published online Mar 20, 1994. http://dx.doi.org/10.3347/kjp.1993.31.3.183
Copyright © 1993 by The Korean Society for Parasitology


Transmission electron microscopic ultrastructures of the male germinal cells of Fibricola seoulensis
W M Sohn,^*¹ and S H Lee²
¹Department of Parasitology, College of Medicine, Inje University, Pusan 614-735, Korea.

Received July 06, 1993; Accepted July 28, 1993.
Abstract
A transmission electron microscopic study was performed to observe the ultrastructures of the male germinal cells and spermatozoa of Fibricola seoulensis. Spermatogonia were found in the periphery of the testis and characterized by large nuclei and comparatively little cytoplasms. Spermatocytes contained an oval to spherical nucleus. Their nuclear volume was little larger in comparative to that of cytoplasm, and the chromatin was comparatively little. The early spermatids were characterized by a great amount of cytoplasm, and numerous mitochondria encircled the nucleus. In a more advanced spermatids the electron-dense strands of chromatin appeared in the nucleus, and a pair of rootlet of the axoneme and a microtubule-organizing center (MTOC) were observed near the nucleus. The sectioned spermatozoa were found in the testis and the seminal vesicle. Their cross sectional views were divided into 6 types when they were distinguished on the basis of the morphology and components. The spermatozoa of F. seoulensis showed two flagella of 9+1 type axoneme.

Figures

Figs. 1-4
Fig. 1. The spermatogonia at periphery of the testis, which characterized by large nucleus (N) and comparatively little cytoplasm containing mitochondria (M), numerous free ribosones and sparse rough-surfaced endoplasmic reticulum. × 7,500. Fig. 2. A spermatogonium is dividing. Note the dividing chromatin mass, irregular contour of nuclear membrane (arrow heads) and numerous mitochondria (M). ×7,500. Fig. 3. The primary spermatocyte showing the oval or elliptical nucleus (N) and cytoplasm with mitochondria and free ribosomes. × 11,250. Fig. 4. The secondary spermatocyte showing the oval-shaped nucleus (N) with chromatin patches and the cytoplasm containing mitochondria, free ribosomes, rough-surfaced endoplasmic reticulum and microtubules. × 7,500.

Figs. 5-8
Fig. 5. The spermatids at earliest stage of development. Note the numerous mitochondria (M) encircled the nucleus (N). × 15,000. Fig. 6. The spermatids contain the nucleus (N) with the chromatins of electron-dense strands, a pair of rootlets of axoneme (arrow heads) and a microtubule-organizing center (MTOC: arrow mark). × 11,250. Fig. 7. The spermatid enclose by plasma membrane showing nucleus (N), mitochondria (M) and MTOC (arrow mark). × 22,000. Fig. 8. The spermatids contained the non-condensed nuclei, the head portion of spermatozoa and a crytalline body. × 7,500.


	Figs. 9-16 Figs. 9-16. The various cross sectional views of spermatozoa. Figs. 12 & 13. The head portion with the electron-dense nucleus (N) and mitochondria (M). Figs. 14 & 15. The middle portion with the nuclear cylinder (arrow head) and mitochondria. Fig. 16. The posterior portion showing the biflagella and the 9+1 arrangement of axonemes. × 30,000.

Figs. 17-19
Fig. 17. The longitudinal sections of the spermatozoa. × 10,000. Fig. 18. The magnification of the boxed area in Fig. 17. Note the electron-dense chromatin (C) twisted in helical shape and the ruffled nuclear envelope (arrow heads). × 27,500. Fig. 19. The spermatozoa in the seminal vesicle. Note the spermatozoa of 2 flagella type (arrow mark) and the abnormal ones with 3-4 axonemes (arrow heads). × 10,000.

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