• Animal cells and systems
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• v.6 no.1
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• pp.75-80
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• 2002

A study on the effects of bisphenol A (BPA) on sex differentiation and gonadal development in medaka, Oryzias latipes, was investigated by histological examination. The fish were exposed to aqueous solutions of BPA at nominal concentrations of 50, 100, and 200 $\mu\textrm{g}$/L from newly-hatched larvae stage to 70 d. The ovaries of female fish were composed of oocytes at the chromatin nucleolus and peri-nucleolus stages at 20 d after the exposure. The testes contained a number of spermatogonia and spermatocytes at 30 d. In the process of sex differentiation. gonadal development was not different in all experimental groups until 30 d after the exposure. At 70 d after the exposure, however, advanced development of oocytes in the ovary and inhibition of spermatogenesis in the testis were observed in the BPA-treated groups compared to the non-treated controls. More females than males were identified in the 50 and 100 $\mu\textrm{g}$/L BPA-treated groups, in comparison to the 200 $\mu\textrm{g}$/L BPA-treated group and non-treated controls. Medaka exposed to 200 $\mu\textrm{g}$/L BPA were bigger compared to other experimental groups. The present study suggests that BPA may lead to problems in either mating or sexual behavior due to the difference in growth and disparity of sexual maturation between male and female fish.

• Development and Reproduction
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• v.7 no.2
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• pp.89-93
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• 2003

The present study observed the ultrastructure of testis of bluespotted mud hopper(Boleophthalmus pectinirostris), and sperrnatogenesis was discussed also. The testis was surrounded by a thin adventitia, inside which spermatocyst composed the parenchyma of testis. Each lobule was enwrapped by many spermatocysts, which were filled with different kinds of spermatogenic cell clusters at the same developmental stage. In the lobule lumen there are large numbers of spermatozoa The thin adventitia(outer wall) of testis was composed of outer epithelium, and the underlying layers, such as collagen fiber layer, and myoid tissue. The myoid tissue elongated into the inside of testis, became the main componentof interstitium between spermatocyst where sperrnatogenesis occurred. In addition interstitial cells containing dense homogeneous nucleus and abundant mitochondria were observed. Spermatogonia contained round nucleus with diffuse chromatin and nucleolus, and dense nuclear bodies surround by mitochondria in cytoplasm. The synaptonemal . complex was observed in primary spermatocytes clearly. Early spermatid presented larger round nucleus composed of granular chromatin, which was located in the center of cytoplasm. The nucleus of mid-spermatid composed of finely granular chromatin lied on one side of spermatid, and abundant mitochondria had migrated another side. A nuclear fossa appeared in the site near mitochondria in late-spermatid, and the centriole was formed in nuclear fossa.

• BMB Reports
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• v.41 no.9
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• pp.664-669
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• 2008

Znf230, the mouse homologue of the human spermatogenesis-related gene, ZNF230, has been cloned by rapid amplification of cDNA ends (RACE). This gene is expressed predominantly in testis, but its expression in different testicular cells and spermatogenic stages has not been previously analyzed in detail. In the present study, the cellular localization of the Znf230 protein in mouse testis and epididymal spermatozoa was determined by RT-PCR, immunoblotting, immunohistochemistry and immunofluorescence. It is primarily expressed in the nuclei of spermatogonia and subsequently in the acrosome system and the entire tail of developing spermatids and spermatozoa. The results indicate that Znf230 may play an important role in mouse spermatogenesis, including spermatogenic cell proliferation and sperm maturation, as well as motility and fertilization.

• Development and Reproduction
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• v.23 no.4
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• pp.323-331
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• 2019

In this study, an experiment was conducted to investigate the annual reproductive cycle of a Korean flat bittering, Acheilognathus rhombeus, from Ogok-myeon located in Seomjin River. The reproductive cycle was examined histologically regarding water temperature and day length of the habitat, the gonadosomatic index (GSI), and developmental characteristics of female and male gonads. The maximum GSI was found to be 3.50±0.53 and 1.36±0.14 for females and males, respectively, when the water temperature and day light was 16.9℃ and 11.3 hours, respectively in October 2018. On the other hand, the minimum GSI was found to be 0.16±0.09 and 0.69±0.15 for males and females in December 2018 and February 2019, respectively. The ovipositor of females appeared from August to November 2018. We compared and calculated the stages of germ cell developmental characteristics in the testis and ovaries to determine the reproductive cycle. According to the result, we classified the female A. rhombeus reproductive cycle into four phases, which are ripe and spawning phase (October), degenerative phase (November to December), growing phase (January to March) and mature phase (April to September). The annual reproductive cycle of male A. rhombeus was categorized into four phases: mature phase (June to October), degenerative phase (November to March), resting phase (April) and growing phase (May). The Korean flat bittering is an autumn-spawner as the main spawning season in October. In male, testicular spermatogonia appeared all year-round, and the ripe and releasing phase, which is characteristics of the spawning season in other fish, did not appear.

• Korean Journal of Animal Reproduction
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• v.23 no.1
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• pp.37-43
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• 1999

The image analyser was used for the measurement of the morphological changes of the spermatogenic cells and seminiferous tubules in the pheasant during the breeding and non breeding season. 1. The seminiferous tubules were enlarged 2.57 times during the breeding season than during the non breeding season. Only Sertoli cells and spermatogonia in the seminiferous tubules can be found during the non breeding season. 2. There is no significantly difference in the ratio of nucleus area against that of cell size in the spermatogonium between breeding and non breeding season. The ratio of area was 28.71% and 29.11%, respectively. However, the enlargement of spermatogonium was noticed during the non breeding season. 3. The highest value of the ratio of the nucleus area against that of cell size among the germ cells was measured 37.40% in the pachytene phase of the spermatocyte during the breeding season. 4. The ratio of nucleus area against that of cell size in the spermatid was 22.53%.

• Applied Microscopy
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• v.33 no.4
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• pp.267-274
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• 2003

The ultrastructures of spermatogenesis and sperm in Xiphophorus maculatus, ovoviviparous fish were investigated by electronmicroscopy The testis of Xiphophorus maculatus contained numerous testicular sacs, and spermatogenesis was synchronized in these testicular sac. In the case of spermatogonium, the nucleus was comparatively large ellipsoidal, and the nucleolus and mitochondria showed a marked development. The size of primary spermatocyte was smaller than that of spermatogonia, and that of secondary spermatocyte was smaller than that of primary spermatocyte. The chromatin of spermatocyte was highly condensed according to their development. The nucleus with electron-dense was round shape. In spermiogenesis, flagella started to be formed and chromatin was more condensed. The mitochondria were rearranged along the tail. The sperm was formed by loss of cytoplasm. The head of mature sperm was long cone shape and had not acrosome. The microtubules of flagella were arranged 9+2 structure. Also, the sperm has a loop-like structure at the end of a tail.

• Journal of Embryo Transfer
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• v.23 no.2
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• pp.119-125
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• 2008

A 3-month-old American Cocker spaniel was presented at the Veterinary Teaching Hospital, Chungbuk National University, for examination of urinary tract after dissection of vaginal mass at local clinic before 10 days. Clinical examination of the affected bitch revealed a normal sized vulva in a normal anatomical position with a grossly enlarged clitoris, which contained an os clitoris. On examinations of the genital gland, there were testis, epididymis, ductus deferens and uterus. The histology of both gonads was primarily testis. Seminiferous tubules were divided into many parts by fibrous connective tissue. A small number of spermatogonia was present, but large numbers of Leydig's cells were existed. A normal female karyotype (78, XX) was detected in metaphase spreads obtained from cultured peripheral lymphocytes. Y chromosome specific sequences were not detected in genomic DNA by PCR. After 27 months, the os clitoris was larger than 3-month-old dog and os bone was more calcified than young age. Combining the results of cytogenetic, molecular genetic and histological examinations, the dog was diagnosed as a female hermaphrodite with Sry-negative XX sex reversal.

• Applied Microscopy
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• v.22 no.2
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• pp.97-117
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• 1992

In order to study process of spermiogenesis of the Korean greater horseshoe bat, Rhinolophus ferrumequinum korai, the cycle of seminiferous epithelium was examined by the light and electron microscope and the following results were obtained based on the epithelial cell differentiation. 1. Spermiogenesis occurred from early July to mid-Octber, and spermatogenic activity was vigorous from mid-August to late September. Spermatocytes including spermatogonia were found to be degenerated in only July. It is deduced that the degeneration serves as the mechanism to regulate effective use of energy to prepare for mating and hibernating periods, and regulation of breeding cycle. 2. Spermiogenesis of the Korean greater horseshoe bat was divided according to differentiation of the cell structure, into Golgi, cap, acrosome, maturation and spermiation phases; Golgi, cap and spermiation phases were further divided into two steps of early and late phase respectively, and acrosome phase into three steps of early, mid and late phases, and maturation phase has only one step. Hence, the spermiogenesis consists of ten phases. The first research was done in this article on the changes of chromatin with nucleus, the time of appearance and disappearance of chromatin granules, in case of Korean greater horseshoe bat (Rhinolophus ferrumequinum korai). Chromatin granule began to be condensed in late Golgi and the condensation proceeded to form an irregular mass of a electron-dense chromatin in a form of circular cylinder in the center of nucleus at the phase of maturation. Finally, the chromatin condensation proceeded and perfect nucleus of sperm with homogeneous density was formed when the sperm was separated from Sertoli cell. Therefore, appearance and disappearance of chromatin granules occurred in the period of time between late Golgi and maturation phase, The tail of sperm began to develop in early cap phase, Numerous lipid droplets were obseved in the cytoplasm of spermatids during the maturation phase, which seemed to be used as energy source necessary to make mature sperm during spermiogenesis.

• Journal of Life Science
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• v.11 no.3
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• pp.218-229
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• 2001

The cycle of the seminiferous epithelium and spermiogenesis in three species if the genus Crocidura, the lesser white-toothed shrew, C. suaveolens, the Japanese white-toothed shrew, C. dsinezumi and the big(=Ussuri) white-toothed shrew C. lasiura, in the breeding season were studied with light and electron microscopes. The three species examined are distinguished from each other in the morphology of the seminiferous epithelium and the spermiogenesis, suggesting that these morphological characteristics are useful for the identification of the species. C. dsinezumi and C. lasiura, however, share many characteristics which are not common in C. suaveolens, as follows: In both species, 1) the cycle of the seminiferous epithelium is composed of 10 stages against 11 stages in C. suaveloens; 2) the earliest intermediated type spermatogonia is observed at stage I against stage III in C. suaveolens; 3) the spermatids of step 5 is observed during the stages V-VI against stages V-VII in C. suaveolens; 4) the acrosomal extension occurs during the stages VIII-X against tages IX-XI in C. suaveolens; 5) the condensation of the nucleus occurs simultaneously whereas it begins from the middle and along the nuclear membrane in C. suaveolens; 6) the capitular length in acrosome phase is shorter(about 2/3 of the diameter of the proximal centriole) than in C. suaveolens(longer than the diameter of proximal centriole; 7) length of the post nuclear cap is shorter(less than a half of the nucleus) than in C. suaveolens(about a half on the nucleus). Hudging from the similarities in the spermatogenesis in C. dsinezumi and C. lasiura, the relationship between them seems to be close compared to those with C. suaveolens.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.525-532
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• 2015

In order to determine the testicular cycle of the Asian toad, Bufo gargarizans, adult males of the species were captured around Jeongeup city (Jeollabuk-do, Korea) during March, 2012 to February, 2013 and the gonadosomatic index (GSI) and the changes of germ cells in their testes were investigated throughout the year. The study indicated that the spermatogenesis in the seminiferous tubule of testes began in April and became most active in July. The recorded GSI was the highest and the cross area of seminiferous tubule was the widest in this period. The seminiferous tubules at the post spawning stage appeared in February, the largest amounts occurred in March and primary spermatogonia also appeared in this period. The GSI and the cross area of seminiferous tubules were found to be the lowest in March, indicating a testicular cycle with potentially continuous spermatogenic process. According to the findings above, it is confirmed that testicular spermatogenesis takes place actively between April to July in male Asian toad and that their breeding season is February to March.