• Development and Reproduction
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• v.19 no.4
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• pp.209-215
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• 2015

Red spotted grouper, Epinephelus akaara is a popular aquaculture species in many Asian countries. This species is a protogynous hermaphrodite that first differentiates into female and changes to male later. Due to this reproductive characteristic, stable supply of male and female gametes is a key to the success of seed production in this species. Thus, understanding early gonadal differentiation is required to develop effective sex control techniques. Red spotted grouper were reared in indoor tanks and sampled every 5 days from 40 days post-hatch (DPH) to 130 DPH. Changes of gonadal tissues were examined and analyzed by means of histology. A pair of gonadal primordium has already existed underneath the kidney in the posterior part of the body cavity at 38 DPH when this study began. Gonadal primordia of 38, 40 DPH consisted of germ cells surrounded by a few somatic cells. The blood vessel was observed in the gonadal primordium at 45 DPH. The number of somatic cells and size of gonadal primordium increased age-dependently up to 60 DPH. Formation of ovarian cavity was obvious by two protuberant aggregations of somatic cells at 65 DPH. Completed ovarian cavity and oogonia were first observed in the gonad of one fish sample at 105 DPH. Based on these histological observations, it can be suggested that induction of primary male differentiation could be more successfully applied at around 60 DPH in this species.

• BMB Reports
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• v.49 no.9
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• pp.488-496
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• 2016

Estrogens are the key hormones regulating the development and function of reproductive organs in all vertebrates. Recent evidence indicates that estrogens play important roles in the immune system, cancer development, and other critical biological processes related to human well-being. Obviously, the gonads (ovary and testis) are the primary sites of estrogen synthesis, but estrogens synthesized in extra- gonadal sites play an equally important role in controlling biological activities. Understanding non-gonadal sites of estrogen synthesis and function is crucial and will lead to therapeutic interventions targeting estrogen signaling in disease prevention and treatment. Developing a rationale targeting strategy remains challenging because knowledge of extra-gonadal biosynthesis of estrogens, and the mechanism by which estrogen activity is exerted, is very limited. In this review, we will summarize recent discoveries of extra-gonadal sites of estrogen biosynthesis and their local functions and discuss the significance of the most recent novel discovery of intestinal estrogen biosynthesis.

• Clinical and Experimental Reproductive Medicine
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• v.10 no.2
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• pp.25-37
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• 1983

As the cytogenetic developed, cytogenetic study has also developed progressively. This study is a systematical cytogenetic and clinico-hormonal analysis of 20 cases Wp.ere gonadal dysgenesis was diagnosed and deferred to the Dept. of obstetrics and Gynecology, Yonsei University, Medical School from Jan. 1974 to Aug. 1983. Twenty patients with the diagnosis of gonada dysgenesis have been assesed as to possible correlations between clinical, homonal and cytogenic findings. The desults were as follows; l. Gonadal dysgenesis were found in 20 cases, consisting of 15 cases (75%) of turnurs syndrome, 4 case of pure gonadal dysgenesis (20%), 46. XX and 1 case of mixed gonadal dysgenesis, 45,XO/46,XY. 2. Patients with XO karyotype, turner's ryndorme, have a resonably constant clinical picture of sexual infantilism with streak gonads, short status and webbed neck. 3. 17 cases were found primary amenorhea and two cases were noted with 2 ndary amenorrhea. one case has been presented with menstruation. 4. The rudimentary streak gonads were found in 7 cases of 8 cases and one case has a rudimentary streak gonad on one side and a testis on the contralateral side. 5. The study showed that potients with gonadal dysgenesis had an average of about 4-8 times higher basal FSH and about 3-7 times higher basal LH than that of the early follicular phase of normal menstrual cycle. 6. Two cases of three gonadal dysgenesis patieats, who performed LH-RH challage test, showed that the serum FSH levels reached the maximal level at 30 min after injection of CHRH and the serum LH level reached the maximal level at 60 min ofter injection of LHRH one case showed no significant response to LH-RH injection. Thus, bu studying simultoneously the clinical, cytogenic, hormonal aspects and visualization of gonads, we have gained some practical insight into the requirements for proper disgnosis and treatment.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.6
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• pp.557-562
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• 1995

In this study, characteristics of chick primordial germ cells (PGCs), which is the founder cell of the germline, and gonadal development of the chick embryo between 12hrs and 6 day of incubation were investigated by transverse serial sections of chick embryos under the light microscopic observation. In embryo stage 20 (3 day of incubation), there are a lot of PGCs at the mesenchym, which were moving to the thickened epithelium (gonadal ridge). The PGCs arrive at both right and left gonad primordial in equal number prior to stage 24 (4 day of incubation), but in the following stages, the distribution of the PGCs became asymmetrical. More PGCs colonized the left than the right gonad, but the reason for the unequal distribution of PGCs is uncertain. The PGCs have mostly settled in the gonadal ridge (GR) at 6 day embryo. This study was conducted to investigate characteristics of the PGC migration and gonadal formation and observe the best condition for PGC isolation, culture and to attempt the possibility of the production for transgenic germline chimeras with manipulated PGCs.

• The Korean Journal of Malacology
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• v.25 no.1
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• pp.29-33
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• 2009

This study devised and tested a histological staging system for gonadal development in the trumpet shell, Charonia sauliae, which was collected along the south coast of Jeju Island, South Korea. This paper details for the first time the gonadal development characteristics of C. sauliae. Ovary and testis development in C. sauliae can be roughly divided into five stages: growing, mature, spent, degenerative, and resting. The trumpet shelll has multiple fecundation and fertilization during the spawning season for out-of-step gonadal development in high-temperature and low-salinity environments. Female trumpet shell tended to have larger shells and were more abundant than males (64.26% of all animals collected were female).

• Environmental Analysis Health and Toxicology
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• v.17 no.1
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• pp.7-11
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• 2002

Effects of nonylphenol (NP) on gonadal development and growth of olive flounder, Paralichthys olivaceus were investigated. NP treatment was carried out to fry fish (during 55 to 64 days after hatching) using oral adminstration at nominal NP concentrations of 50, 100 and 150 tig/g BW Gonad before NP treatment was sexually undifferentiated as observed with mostly gonia cells. At 159 days after hatching, ovarian lamella of ovary were filled with oogonia and perinucleolus oocytes. On the other hand, testicular lobules of the testis were occupied by spermatogonia, spermatocytes and spermatids. Histological observation of ovary and testis development was any different between the control and NP treated groups. However, growth was significantly increased in NP treated groups than control groups (P< 0.05). These results considerate that NP has any effect for sex differentiation and gonadal development, but act for early growth in olive flounder.

• Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.207-212
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• 2005

Directional (sinistral) asymmetry (DA) occurs when the traits of one side of a supposedly bilaterally symmetrical organism differ in a random way from those of the other side. We examined asymmetries in gonadal growth traits within both sexes of hatchery reared ayu, Plecoglossus altivelis. The pattern of the gonadal growth from hatching to 320 days after hatching was a type of DA except for the growth in gonad weight from 140 to 180 days after hatching, although the ovary of the right side tended to exhibit more pronounced DA phenomenon.

• Journal of Digital Convergence
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• v.11 no.7
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• pp.237-242
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• 2013

When abdomen and pelvic were scanned with 128 channel MDCT, the gonadal exposure dose was measured with and without gonadal shield and the obtained images were evaluated. As a result, during abdominal MDCT scan, the gonadal exposure dose was measured $16.5{\pm}0.5$ mGy when the gonad shield was not used, and it was $7.5{\pm}0.3$ mGy when the large gonad shield($650m^2$) was used, which showed the effect of reduction in the gonadal exposure dose by 54%. During pelvic MDCT scan, the gonadal exposure dose was $9.5{\pm}0.3$ mGy when the gonad shield was not used, and it was $2.8{\pm}0.2$ mGy when the large gonard shield($650m^2$) was used, which showed the effect of reduction in the gonadal exposure dose by 70%. The images were obtained when using the gonad shield and when not using it during MDCT scan, and as a result of analyzing them with 5-point Likert scale, in the abdominal image, it was 4.1 points irrespective of whether using the gonad shield or not. And also, in pelvic scan, it was 1.2 points when the gonad shield was used, and 4.1 points when it was not used. With the results above, it is considered that during the abdominal 128-MDCT scan, by using the gonad shield, the images should be obtained without being degraded and the exposure dose must be reduced.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.3
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• pp.457-465
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• 1999

Objective: The presence of Y chromosome in patients with gonadal dysgenesis is related to the risk of gonadoblastoma. Since the patients with abnormal sexual differentiation may have cryptic Y mosaicism, it is important to detect the presence of Y material in these patients. But sometimes it is difficult to detect Y material only with karyotyping. This study was performed to evaluate the usefulness of the SRY gene screening in blood and gonad by using PCR in detecting the presence of Y material and possible tissue mosaicism in patients with gonadal dysgenesis as Turner syndrome and 46,XY pure gonadal dysgenesis (PGD, Swyer syndrome). Method: In 26 patients with gonadal dysgenesis, we screened for Y material by using PCR for SRY gene in peripheral leukocytes and in gonadal tissues of some patients. They were 22 cases of Turner syndrome (7 45,XO, 2 46,Xi(Xq), 3 45,XO/46,XX, 5 45,XO/46,Xi(Xq), 1 45, XO/46,XY, 1 45,XO/46,Xi(Yq), 1 45,XO/47,XYY, 1 46,XX,del(X)(q24) and 1 46,X,+mar) and 4 cases of 46,XY pure gonadal dysgenesis. PCR for SRY gene in the gonadal tissue was performed in 5 Turner syndrome and 2 PGD to determine the cryptic Y mosaicism between blood and gonad. Results: By using PCR analysis for SRY, Y chromosome material was detected in the blood of 4 of 22 Turner syndrome patients (45,XO/46,Xi(Xq), 45,XO/46,Xi(Yq), 45,XO/46,XY, and 45, XO/47,XYY), 3 of 4 46,XY pure gonadal dysgenesis. Discrepancy between karyotyping and blood PCR for SRY was noted in 1 Turner syndrome (45,XO/46,Xi(Xq)) and 1 PGD. Laparoscopic gonadectomy was performed in Y containing or SRY positive cases. In addition, PCR analysis for SRY in the gonads of 5 Turner syndrome and 2 PGD showed discrepancy between blood and gonad or between both gonads in 3 Turner syndrome (45,XO/46,Xi(Xq), 45,XO/46,Xi(Y q), 45,XO/46,XY) and 2 PGD patients. Conclusion: In gonadal dysgenesis, PCR analysis for SRY gene is useful to detect the cryptic Y mosaicism that is sometimes undetected by karyotyping. And since there may be tissue mosaicism, it is necessary to evaluate Y mosaicism in various tissues even in the case without Y chromosome on karyotyping.

• Animal cells and systems
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• v.5 no.1
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• pp.37-44
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• 2001

Gonadal development, reproductive cycle, gonad index, meat weight rate, and first sexual maturity of the top shell, Omphalius rusticus were Investigated monthly by histological observations. Specimens were collected from the west coast of Korea during the period from January to December in 1999. O. rusticus is dioecious and oviparous. The gonad is widely situated on the surface of the digestive g1and located in the posterior spiral meat part in the shell. The ovary and the testis were composed of a number of oogenic follicles and several spermatogenic follicles, respectively. Ripe oocytes were approximately 120-130 $\mu$m in diameter. The meat weight rate peaked in June (27.7%), and then rapidly decreased in September (19.5%). Monthly changes in the gonad index in both sexes reached the maximum in June, and then sharply decreased in September. Percentages of first sexual maturity of female and male snails ranging from 9.0 to 9.9 mm in shell heights were 58.3% and 54.5%, respectively, and 100% in those over 11.0 mm in both sexes participated in reproduction. Reproductive cycle of this species can be categorized into five successive stages: in females, early active (October to April), late active (December to June), ripe (April to September), spawning (July to September) and recovery (September to January): in males, early active (November to March), late active (December to June), ripe (April to September), spawning (July to September) and recovery (September to December). Gonadal development, gametogenesis, reproductive cycle, and spawning were closely related to the seawater temperature.