• Journal of Life Science
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• v.15 no.3 s.70
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• pp.387-396
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• 2005

The aims of the study were to establish a short-term screening test for detecting testicular toxicity of chemicals in rats and to determine whether a 2-week administration period is sufficient to detect testicular toxicity of 2-bromopropane (2-BP) as an example. Male Sprague-Dawley rats were subcutaneously administered with 1000 mg/kg/day of 2-BP or its vehicle for 2 weeks. Ten male rats each were sacrificed on days 3, 7 and 14 after the initiation of treatment. Parameters of testicular toxicity included genital organ weights, testicular sperm head counts, epididymal sperm counts, motility and morphology, and qualitative and quantitative histopathologic examinations. The early histopathological changes observed on day 3 of treatment included degeneration of spermatogonia and spermatocytes, multinuclear giant cells, mature spermatid retention, vacuolization of Sertoli cells, and decreased number of spermatogonia in stages II and V. On day 7 of treatment, atrophy of seminiferous tubules, exfoliation of germ cells, degeneration of spermatogonia and spermatocytes, multinuclear giant cells, mature spermatid retention, vacuolization of Sertoli cells, decreased number of spermatogonia in stages II and V, and decreased number of spermatocytes in stages VII and XII. On day 14 after treatment, a significant decrease in the weights of testes and seminal vesicles was found. Atrophy of seminiferous tubules, exfoliation of germ cells, degeneration of spermatogonia and spermatocytes, mature spermatid retention, vacuolization of Sertoli cells, decreased number of spermatogonia in stages II and V, and decreased number of spermatocytes in all spermatogenic stages were also observed. In addition, a slight non-significant decrease in testicular sperm head counts, daily sperm production rate and epididymal sperm counts was found. The results showed that 2 weeks of treatment is sufficient to detect the adverse effects of 2-BP on male reproductive organs. It is considered that the short-term testicular toxicity study established in this study can be a useful tool for screening the testicular toxic potential of new drug candidates in rats.

• 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.

• Development and Reproduction
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• v.13 no.1
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• pp.25-33
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• 2009

The cycle of the seminiferous epithelium and development of spermatids of Apodemus speciosus peninsulae were observed using a light microscope. On the basis of developing spermatocyte and spermatid, the cycle of the seminiferous epithelium was divided into 9 stages. Type Ad spermatogonia were appeared in all stages ($I{\sim}IX$). The Ap, In, and B types of spermatogonia were appeared from stage I, II and III, and IV, respectively. In prophase of first meiosis, the leptotene spermatocytes appeared from stage V and VI, zygotene spermatocytes from stages I, II, VII, VIII, and IX, pachytene spermatocytes from stage III to VII, diplotene spermatocytes in the stage VIII, and secondary spermatocytes in stage IX. On the basis of morphology of spermatid head, developing of nuclear and acrosome and the morphological change of cytoplasm, the developing of spermatids was divided into 12 steps. Considering all the results, A. s. peninsulae displayed very similar result with A. agrarius coreae that is allied species when compare correct characters developing of spermatids with spermatogonia and appearance time of the spermatocyte. Appearance time of the same cell and number of spermatogonial generation was thought that characters of the species, and information may be useful in identifying the species.

• Biomedical Science Letters
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• v.11 no.4
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• pp.545-553
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• 2005

The present study provides descriptions of the cellular associations of the seminiferous epithelium cycle in the Crocidura shantungensis. The cycle of the seminiferous epithelium was divided into 14 stages, and developing spermatids were subdivided into 15 steps. The Golgi phase occurs the first two steps, and the cap phase had the next four consecutive steps. The acrosomal and maturation phases were consisted of steps $7\~14$, and the remaining one step consisted the spermiation phase. The Ad type of spermatogonia was observed whole stages, and Ap, In and B spermatogonia were observed from stage II to stage VI. The preleptotene, leptotene and zygotene of primary spermatocytes were observed from VII to XIV stages, and pachytene spermatocyte was observed from I to XII stages. The diplotene spermatocyte was observed XIII stages, and meiotic figures and secondary spermatocytes were observed stage XIV. Our results provide the foundation for a variety of future studies of the spermiogenesis of C. shantungensis.

• Toxicological Research
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• v.11 no.1
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• pp.51-55
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• 1995

The present experiment was carried out to investigate whether X and Y chromosome dissociation in the primary spermatocytes of mice can be used as an in vivo assaying system that detect environmental mutagens. For this purpose, alkylating agents (EMS, MMS and MMC), which are strong mutagens, were administered to ICR male mice 12-15 weeks old. The mean frequencies of previously dissociated X-Y chromosomes and autosomes of the control group were 7.34-7.45% and 0.92-1.04%, respectively. The frequencies of X-Y dissociation in the mutagen-treated groups with 10.0 mM EMS and 5.0 mM MMS were about 3.3-4.6 times higher than that in the control group, but there were no significant differences in dissociation of autosomes in both the control and the mutagen-treated groups. These results suggest that X-Y dissociation in the primary spermatocytes of mice can be used as an in vivo short-term assaying system for environmental mutagens.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.453.2-453
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• 2001

• Korean Journal of Veterinary Research
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• v.31 no.4
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• pp.355-365
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• 1991

This study was conducted in order to observe the changes in cellular association of seminiferous tubules from 16 to 24 weeks of age and to obtain the cycle and relative duration of the seminiferous epithelia from 28 to 44 weeks of age in Korean native dogs. The results were summarized as follows; 1. Gonocytes were seen at 16 weeks of age, however they were not observed as from 20 weeks of age. Both type A and type B-spermatogonia occurred from 20 weeks, while primary spermatocytes were found from 20 weeks. Secondary spermatocytes and spermatids appeared from 28 weeks. Spermatozoa were observed at first at 28 weeks of age. 2. Type A-spermatogonia appeared approximately 1.6 times as many at stage II compared to stage I, while the same numbers of cells were seen in both stage I and VII, showing the least number among VIII stages of the cycle of the seminiferous epithelia. The type B-spermatogonia were found from stage VI to VIII, Leptotene phase of the primary spermatocyte divided from type B-spermatogonia in stage VII observed at the stage VIII. Pachytene phase of the primary spermatocytes were shown the least in number at stage IV. The secondary spermatocyte could be seen only at stage IV. 3. The relative frequency of each stage from stage I to VIII of the cycle of the seminiferous epithelia was 30.3, 12.0, 9.8, 4.2, 8.5, 10.5, 11.4 and 13.4% respectively. Thus the establishment of spermatogenesis in Korean native dog was completed from 28 weeks of age.

• Animal cells and systems
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• v.16 no.2
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• pp.104-113
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• 2012

The nucleolus is a distinct nuclear territory involved in the compartmentalization of nuclear functions. There is some evidence of a relationship between nuclear fragmentation during spermatogenesis and chromatoid body (CB) formation. The CB is a typical cytoplasmic organelle of haploid germ cells, and is involved in RNA and protein accumulation for later germ-cell differentiation. The goal of this study was to qualitatively and quantitatively describe the nucleolar cycle during the spermatogenesis of $Phrynops$ $geoffroanus$ (Reptilia Testudines), and compare this nucleolar fragmentation with CB formation in this species through the use of cytochemical and ultrastructural analysis. Qualitative analysis showed a fragmentation of the nuclear material after pachytene of the first meiotic division in the primary spermatocytes. Quantitative analysis of the nucleolar cycle revealed a significant difference in the number of nucleoli and in the size of the nucleolus between spermatogonia and early spermatids. Using ultrastructural analysis, we recorded the beginning of the CB formation process in the cytoplasm of primary spermatocytes at the same time as when nuclear fragmentation occurs. In the cytoplasm of primary spermatocytes, the CB was observed in association with mitochondrial aggregates and the Golgi complex. In the cytoplasm of early spermatids, the CB was observed in association with lipid droplets. In conclusion, our data show that the nucleolus plays a role in the CB formation process. During spermatogenesis of $P.$ $geoffroanus$, the CB is involved in some important biological processes, including acrosome formation and mitochondrial migration to the spermatozoon tail and middle piece region.

• Journal of Aquaculture
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• v.22 no.1
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• pp.5-10
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• 2009

Spermatogenesis in male yellow croaker Larimichthys polyactis was histologically investigated by sampling testicular tissue from $2{\sim}3$ years old wild fishes captured from the coast of Mok-Po, South Korea. Spermatogenesis was characterized histologically, and staged according to the most advanced type of germ cell present. Annual reproductive cycle was classified into the following successive 4 stages: spermatogonia from August to September (rest stage), spermatogonia and spermatocytes from October to December (growth stage), spermatogonia, spermatocytes and spermatids from January to February (maturation stage), spermatogonia, spermatocytes, spermatids and spermatozoa from March to May (spermiation stage IV), and regressing testis from June to July (degeneration stage).

• 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.