• Toxicological Research
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• v.17 no.4
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• pp.267-272
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• 2001

This study was carried out to assess the reproductive toxicity of 2-bromopropane (S-BP) using spermatogenesis stage classification and Sertoli cell indices (SCI).Vehicle control olive oil and 2-BP doses of 125, 250 and 500 mg/kg of body weight were injected in the interaperitoneum of 12 weeks male Sprague-Dawley rats for 28 days respectively of SCI on germ cells including the spermatogonia of stages II-III, Ⅵ,Ⅹ, XII, ⅩIII, and spermatocytes of stages VIII (preleptotene), Ⅹ (leptotene), XII (leptotene), V and Ⅵ (pachytene), and the round spermatids of stage Ⅵ. Considering the process of maturation depletion in spermatonesis, spermatogonia may be the primary target cells of 2-BP toxicity.

• Journal of Aquaculture
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• v.14 no.2
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• pp.73-79
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• 2001

Testicular development of the male African lungfish, Protopterus annectens (Owen) was investigated histologically. The testis was found to be an elongated structure that possessed two distinct portions: an anterior spermatogenic part that was made up of a system of testicular tubules and a posterior vesicular part that invaded the kidney tissue. Spermatogenesis can be divided into five stages; primary spermatogonia, secondary spermatogonia, spermatocyte, spermatids and spermatozoa. Based on the gonadosomatic index (GSI) and histological changes observed, the reproductive cycle can be divided onto four distinct stages: resting and quiescent (December to February), growing (March to June) ripe and spent (July to August) and postspawning (September to November). The GSI was the maximum on July when reproductive cells were mature, ripe and ready for spawning; and the minimum in August after fish spawned.

• Korean Journal of Veterinary Research
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• v.35 no.3
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• pp.563-573
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• 1995

To know the effect of Ivermectin(IVM) toxicity in testis, histopathologic changes as well as clinical signs were observed in experimental animals including dogs by the subcutaneous injection with 3-50mg/kg of IVM. Clinically, it was observed to have depression and ataxia in all groups whereas tremor and coma in mice, rats and guinea pigs, coma in hamsters and rabbits, and tremor and salivation in dogs were shown. The clinical signs were different by the dosage of IVM, species and individuals in all animals. Susceptibility to IVM was most sensitive in dogs, especially in a Tosa dog and this was susceptible in mice, hamsters and rabbits, guinea pigs and rats in order. Microscopical observation revealed that the seminiferous tubules of testis had decreased thickness of germinal epithelium due to the necrosis and desquamation of the spermatids and spermatocytes. The progressive pattern by the times of administration showed vacuolar formation between the layer of spermatids and spermatogonia due to the marked necrosis of spermatocytes and the presence of multinucleated giant cells derived from spermatid throughout the seminiferous tubules of testis. Only a layer of spermatogonia, a few spermatogonia, and Sertoli cells wore observed with atrophied wavelike basement membrane in the seminiferous tubules of testis. Necrotic germinal cells, sloughed immature spermatids and spermatocytes were present in the lumen of epididymis and ductus deferens. Microscopical observation showed different susceptibility to IVM with clinical observation in which it was also most sensitive in dogs, especially in a Tosa dog and this was susceptible in rabbits and guinea pigs, hamsters, rats and mice in order. It was considered that IVM affects mainly spermatocyte or spermatid stage in the spermatogenesis and disturbs their developing beyond these stage.

• Applied Microscopy
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• v.33 no.1
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• pp.25-39
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• 2003

Cell differentiation and ultrastructural characteristics in the seminiferous epithelium of Myotis macrodactylus was investigated with the light and electron microscopes. Spermatogenesis has begun at April and finished at September. The nuclei of A spermatogonia (dark and pale type of spermatogonia) were oval, applied to the basal lamina, and surrounded by Sertoli cells. By comparison with other types of spermatogonia, the cell and nucleus of B type of spermatogonium is globular and larger than A types of spermatogonia. The nucleolus appears as a coarse and touches the nuclear membrane. The cell and nucleus of spermatocytes was globular and larger, but primary spematocyte is larger than secondary spermatocyte. Spermiogenesis was divided according to the level of fine structural difference, into Golgi, cap, acrosomal, maturation and spermiation phases; Golgi, cap, acrosomal and spermiation phases were further subdivided into steps of early and late phase respectively, and maturation phase has only one step. Hence, the spermiogenesis has been divided into a total of nine phases. In the change of karyoplasm, the chromatin granules are condensed at late Golgi phase and completed at spermiation phase. The sperm tail began to develop in early Golgi phase and completed in spermiation phase. The process of degeneration of spermatogenic cells in the seminiferous tubules was continually observed from October, before the beginning of hibernation, to hibernation phase (November, December, January, February, March). Immatured spermatogenic cells in the seminiferous tubules have been engulfed by phagocytosis of Sertoli cells during period of degeneration. It is deduced that the adaptative strategy serves as the mechanism to regulate the effective use of energy to prepare for long hibernation and regulation of breeding cycle.

• Korean Journal of Veterinary Research
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• v.25 no.2
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• pp.91-101
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• 1985

This study was conducted in order to observe the changes in cellular associations of seminiferous tubules from 8 to 20 weeks of age and to obtain the cycle and relative duration of the seminiferous epithelia from 24 to 32 weeks of age. Twenty-eight Korean native male goats were used in the experiment and divided into 7 groups, consisting of 4 goats each, with four weeks intervals from 8 to 32 weeks of age. The results were summarized as follows; 1. Gonocytes were seen at 8 weeks of age, however they were not observed as from 12 weeks. Both type A-spermatogonia and type B-spermatogonia occurred from 8 weeks, while primary spermatocytes were found from 12 weeks. Secondary spermatocytes and spermatids appeared from 16 weeks, and increased in numbers sequentially until 32 weeks of age. Spermatozoa were observed at first at 20 weeks of age. 2. Type A-spermatogonia appeared approximately twice as many at stage 2 as compared to stage 1, while the same numbers of cells were seen in both stages 1 and 8, showing the least number among 8 stages of the cycle of the seminiferous epithelia. The type B-spermatogonia were found during the stage 5 to 8, not to be detactable during stage 1 to 4. The number of primary spermatocytes of the leptotene phase increased markedly during stage 1 to 4, and decreased afterwards. The primary spermatocytes of the pachytene phase were shown the least in number at stage 4. The secondary spermatocytes could be seen only at stage 4 and the largest number of spermatids was seen at the stage 4 among 8 stages. 3. The relative frequencies of each stage among stages 1 to 8 of the cycle of the seminiferous epithelia were 27.5, 17.5, 12.8, 5.8, 8.9, 8.3, 12.0 and 7.2% respectively. 4. Some of the nuclei of Sertoli cells transformed from the "parallel" type to the "perpendicular" type. This evolution took place from stage 1 to 6, when the number of "perpendicular" type nuclei reached a peak and the number was decreased in the rest of the stages. Thus, establishment of spermatogenesis in Korean native goats was completed at the age of 20 weeks.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.1
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• pp.5-13
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• 2020

The identify of biomarkers in living tissues is useful to understand the characteristics and functions of the cells. Proteins such as protein gene product 9.5, promyelocytic leukemia zinc finger, NANOG, and stage-specific embryonic antigen-1 have been identified as markers for porcine undifferentiated spermatogonia. In this study, the expression of insulin-like growth factor binding proteins (IGFBPs), a newly discovered porcine spermatogonia marker and pregnancy-associated plasma protein-A (PAPP-A), a protein regulator of IGFBPs, were characterized in 5-day-old porcine testis. To analyze the function of IGFBPs, RT-PCR was performed. IGFBP 2, 3, 4, and 6 were detected in porcine spermatogonia and PAPP-A was detected in basement regions in 5day old porcine seminiferous tubules. PAPP-A was not expressed in spermatogonia, but it was expressed in Sertoli cells. These results suggest that the expression of PAPP-A protein in Sertoli cells may regulate the development and differentiation of testicular cells through the IGF axis in porcine neonatal testis.

• Korean Journal of Animal Reproduction
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• v.11 no.1
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• pp.33-41
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• 1987

The cycle of the seminiferous epthelia in the testis of matured Korean Native Cattle was divided into eight stages. The results were summarized as follows: 1. Type A spermatogonia a, pp.ared twice as many at stage 2 as compared to stage 1, while maximum numbers were the average of 2.8 at stage 2. The intermediate and Type B spermatogonia were found during the stage 3 to 8, stage 6 to 8, respectively. The leptolene primary spermatocytes were not observed during the stage 5 to 7, while the pachytene primary spermatocytes were shown the least in number at stage 4, the secondary supermatocytes could be seen only at stage 4 and the round spermatids were not observed at stage 3, 4. 2. The relative frequencies of the eight stages of the cycle of the seminiferous eptithelia were 24.9, 14.2, 19.0, 6.3, 3.7, 7.9, 10.3 and 13.9%, respectively. 3. Some of the nuclei of Sertoli cells transformed from the "parallel" type to the "perpendicular" type. This evolution took place from stage 1 to 5, when the number of "perpendicular" type nuclei reached a peak and the number was decreased in the rest of the stages.sed in the rest of the stages.

• Journal of radiological science and technology
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• v.18 no.1
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• pp.97-110
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• 1995

This study was undertaken to investigate ultrastructural changes according to the radiosensitivity in the spermatogenic cells and Sertoli cell of the seminiferous tubules in Korean native pheasants. During spermatogenetic period, testes were collected from male adult Korean native pheasant and they were used as experimental and control birds. The experimental group was divided into a single-dose whole body irradiation group (400, 600, 800 and 1,000 rads) and a split-dose whole body irradiation groups(400/2, 600/2, 800/2 and 1,000/2 rads). The experimental birds were sacrificed at 24 and 72 hrs after irradiation and the control pheasants were sacrificed at the same time. Ultrastructural changes of Sertoli cells and spermatogonia were investigated by ultrathin section with electron microscope. The results obtained are summarized as follows; 1. The apoptosis was observed after 72 hrs group of the single-dose irradiation of 400 rads. 2. The cytoplasmic organelles of spermatogonia were severely damaged more than that of sertoli cell in 72 hours group of split-dose irradiation of 800 rads. 3. The cytoplasmic organelles of Sertoli cell were severely damaged except the nuclear membrane of Sertoli cells in 72 hrs group of split-dose irradiation of 1,000 rads.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.4
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• pp.281-286
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• 2004

Spermatogenesis and sperm ultrastructure of the marsh clam (Corbicula japonica) were investigated by electron microscopic observations. Testis of the marsh clam consists of numerous spermatogenic follicle containing germ cells in the different developmental stages. Spermatogonia are located nearest the outer wall of the follicle, while spermtocytes and spermatids are positioned nearer to the lumen. Spematogonia are oval-shaped and about $5{\mu}m$ In diameter. Spermatogonia develop into spermatocyte, spermatid and spermatozoon. In the spermatid to about $2{\mu}m$ in diameter, cytoplasm decreases and mitochondria move to the base of the nucleus and fuse into several spheres, the centrioles become orthogonally oriented, a flagellum appears, and an acrosomal vesicle forms. The mature sperm has primitive type, consisting of a head, a midpiece and a tail. The sperm was arrow-shaped, and its head is about $8{\mu}m$ long and comprised of a long nucleus and an acrosome. The four mitochondria encircled the centrosome in midpiece. The flagellum had the classical 9+2 axoneme structure, and axonemal lateral fins in the tail were observed.

• Development and Reproduction
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• v.12 no.3
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• pp.215-220
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• 2008

Sex differentiation process of the spotted Black Bullhead, Pseudobagrus koreanus, was investigated using fish samples of different age after hatching. The primordial germ cells appeared separately under air bladder in 1-day larva (total length: $6.63{\sim}6.95\;mm$). The primordial gonad with a genital ridge developed in 5-day prelarva ($7.50{\sim}9.36\;mm$). The ovarian differentiation started in about 25-day juvenile ($11.58{\sim}13.21\;mm$). The somatic tissues enlongated in the tip of one end of undifferentiated gonad and fused each other. Thus a small ovarian cavity appeared. The testicular differentiation was initiated in 30-day juvenile ($12.19{\sim}13.72\;mm$). The rudiment of sperm duct was appeared in the lower part of the undifferentiated gonad. In 50-day juvenile ($16.28{\sim}17.06\;mm$), the ovary started to fill with peri-nucleolus oocytes, and the spermatogonia started to develop. In 250-day juvenile ($35.49{\sim}51.12\;mm$), the ovary became bigger and filled with oocytes, and the number of spermatogonia started to increase. Considering these results, the spotted Black Bullhead could be a differentiated type in sex differentiation and gonochorism in sexuality.