• The Korean Journal of Zoology
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• v.39 no.2
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• pp.139-146
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• 1996

A studv on the ultrastructural changes of the hermaprodite duct epithelium in spring and summer specimens of a Korean slug Incirovia fruhstorferi was conducted. In spring specimen, the hermaphrodite duct was 0.3 H 0.2 mm in diameter and seemed to be a little bit abnormal feature, due to shrinkage. The epithelium of the duct was composed of cells containing various-sized vacuoles and their cytoplasm showed high electron density. In summer specimen, the hermaphrodite duct was 0.4 $\times$ 0.23 mm in diameter and seemed to be more voluminous than that of the spring specimen. The lumen of the duct in the summer specimen was lined by a epithelium composed of several cell types such as ciliated cuboidal, pseudostratified cuboidal, ciliated columnar and irregular cells. Phasocvtotic activities of the duct epithelium are observed only in the summer specimen. Both of the duct epithelia in the spring and summer specimens were surrounded by connective tissues at their bases. The results obtained suggest that the duct epithelia of the slugs experience seasonal variation in relation to their reproductive cycles.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.201-201
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• 2002

GX-12 is a naked DNA vaccine developed by Dong-A pharmaceutical company for the treatment of mv infection. GX-12 consists of four separate plasmids. This study was performed to evaluate the biodistribution and expression of GX-12 mRNA in gonadal tissues, and to investigate the histopathological changes in rats after repeated intramuscular injection.(omitted)

• Journal of Integrative Natural Science
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• v.16 no.1
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• pp.33-38
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• 2023

The follicle stimulating hormone receptor (FSHR) is a glycoprotein hormone, that belongs to the GPCR superfamily. FSHR plays a major role in reproduction. The aberrant activation of FHS receptor leads to infertility and several reproductive disorders. The recently recognized roles of the FSHR in diverse extragonadal tissues is also closely related to Alzheimer's disease and cancers. Analysing the structural characteristics of the receptor is important in understanding the pathophysiology of diseases associated with the receptor. In this present study, homology modelling of FSHR-TM domain was developed using four different templates. Totally 20 models were developed using single template-based approach and selected three based on the validation of RC plot, RMSD, ProSA, QMEAN and ERRAT values. The developed models would be useful for further research on the structural characteristics and binding characteristics of the FSHR-TM domain.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.3
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• pp.163-174
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• 2009

Objectives: Members of the immortalization-upregulated protein (IMUP) family are nuclear proteins implicated in SV40-mediated immortalization and cellular proliferation, but the mechanisms by which their expression is regulated are still unknown in placenta. To investigate to expression and functions of IMUPs in placenta, we conducted to compare IMUPs expression in normal and preeclamptic placenta tissues and analyzed the function of IMUP-2 in HTR-8/SVneo trophoblast cells after IMUP-2 gene transfection. Methods: The expression of IMUPs was analyzed in placental tissues from the following groups of patients (none underwent labor): 1) term normal placenta (n=15); 2) term with preeclamptic placeneta (n=15); and 3) pre-term with preeclamptic placenta (n=11) using semi-quantitative RT-PCR, RNA in situ hybiridization, immunohistochemistry, and Western blot. In order to evaluate the function of IMUP-2 in HTR-8/SVneo trophoblast cells, IMUP-2 plasmids were transfected into HTR-8/SVneo trophoblast cells for 24 hours. Results: We observed that IMUPs are mainly expressed in the syncytiotrophoblasts and syncytial knot of placental villi. The expression of IMUP-1 was not differences between normal and preeclamptic placenta tissues. However, IMUP-2 expression was significantly higher in preterm preeclamptic placenta tissues than in normal placenta tissues without labor (p<0.001). Furthermore, we confirmed overexpression of IMUP-2 induced apoptosis in HTR-8/SVneo trophoblast cells through up-regulation of pro-apoptotic proteins. Conclusions: These results suggest that the expression of IMUP-2 is involved in placental development as well as increased IMUP-2 expression is associated with preeclampsia through the inducing of trophoblast apoptosis.

• The Korean Journal of Malacology
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• v.30 no.3
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• pp.243-248
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• 2014

This study histologically describes the gonadal development and reproductive cycle of the abalone, Haliotis discus hannai inhabiting Jindo on the southern seashores of Korea. Gonads displayed histologically definitive seasonal changes. The female ratio (F/F + M) was 57% (n = 154/271). The gonad index (GI) of both males and females was the highest (3.3 and 3.9) in June and was the lowest (1.1 and 1.1) in December. The condition index (CI) and meat weight rate (MWR) were highest in May and lowest in October. The pattern of changes in the GI, CI and MWR were similar to the pattern of seasonal changes in gonadal tissues. The reproductive cycle was divided into an inactive stage (November-December), early active stage (January-March), late active stage (March-April), ripe stage (May-June) and spent and degenerative stage (July-October). The main spawning period of Haliotis discus hannai was July to August at Jindo in 2013.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.82-93
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• 1998

Monthly changes of the gonad follicle index (GFI), reproductive cycle, egg-diameter composition, first sexual maturity of the Pacific oyster, Crassostrea gigas, were studied based on the samples which have been collected from the intertidal zone of Poryong west coast of Korea, from January to December, 1996. C. gigas, is dioecious, while a few individuals are alternatively hermaphroditic. Monthly variation of gonad follicle index (GFI) used for determination of spawning period, coincided with the reproductive cycle. GFI increased from April when seawater temperatures gradually increased and reached the maximum in May. And then, GFI sharply decreased from June to September due to spawning. Reproductive cycle of this species can be divided into five successive stages: in females, early active stage (March to April), late active stage (April to May), ripe stage (May to August), partially spawned stage (June to September) and spent/inactive stage (September to February); in males, early active stage (February to March), late active stage (April to May), ripe stage (May to September), partially spawned stage (June to September) and spent/ inactive stage (September to February). The diameter of fully mature eggs are approximately 50um. Spawning occurred from June to September, and two spawning peaks were observed in June and August when the seawater temperature was above $20^{\circ}C$. Percentages of the first sexual maturity of males of 20.1-25.0 mm in shell height were over $50\%$, while those of females of 25.1-30.0 mm in shell height were over $50\%$. All the males of > 30.1 mm and all the females of ^gt; 35.1 mm completed their first sexual maturity. The results suggest that C. gigas has a protandry phenomenon. Sex ratios of 919 oysters observed were 453 females $(49.29\%)$, 429 males $(46.68\%)$, 16 hermaphrodites $(1.74\%)$, and 21 indeterminate individuals $(2.29\%)$. In age class I, sex ratio of males were $64.00\%$, thus, a higher percentage than that of females. It was noted that $64.00\%$ of the young males (age class I) were more functional than females in age class I, but 2-3 year-old oysters showed higher percentage of females. Percentages of hemaphrodites in 2-3 year classes were relatively higher than those in other year classes. Histological pattern of hermaphrodites can be divided into two types: Type I (hermaphrodite having a number of newly formed developing oocytes on the oogenic tissues within a degenerating spermatogenic follicle after discharge of numerous spermatozoa) and Type II (hermaphrodite having two separate follicles in the same gonad).

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.149-156
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• 1999

Steroid hormone is known to cause the dynamic changes of mammalian uterus during reproductive cycle, which are modulated via hypothalamus-pituitary -gonad reproductive endocrine axis. Although there were so many studies about estrogenic regulation of uterine growth and differentiation. There is little information about the effect of estrogen on the expression of various transcription factors involved in gene expression. Thus the present study was designed to demonstrate E induced expression of c-fos, c-jun, hsp25 mRNA in rat uterus. Employing Northern blot analysis, we studied the temporal expressions of c-fos, c-jun, and hsp25 messenger RNAs (mRNAs) elicited by a single 17beta-estradiol (E) treatment in the uteri of bilaterally ovariectomized adult rats. c-fos, c-jun, and hsp25 mRNA levels were increased and peaked at 3h after E administration, and then c-fos and c-jun mRNA levels were rapidly decreased to basal control level while, increased hsp25 mRNA levels were sustained till 12h post E treatment. To test the estrogenic effect on the increase of c-fos, c-jun, and hsp25 mRNA levels, we also examined the effects of antiestrogen (tamoxifen). Pretreatment with tamoxifen effectively blocked the E-induced increase of c-fos, c-jun, and hsp25 mRNA levels at 3h post E treatment. Present results suggest that transient increase of c-fos and c-jun protooncogene mRNA at the early time and simultaneous expression of hsp25 mRNA contribute to the response of uterine tissues to E in adult female rats.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.823-833
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• 1997

To clarify the annual reproductive cycle of the banded catfish, Pseudobagrus fulvidraco (Richardson), the seasonal changes in histological aspect of gonad and liver were examined. The adult fish was raptured from the upper stream of Young-San river, Chunnam in each month from May 1992 to June 1993. Based on the annual changes in GSI (gonadosomatic index), HSI (hepatosomatic index), CF (condition factor) and histological aspects of the gonads, the annual reproductive cycle were classified into 5 periods as follows: 1) Growing phase (from April to early May): The value of GSI increased and the size of oocytes in perinucleolus stage in oocytes increased gradually. Spermatogonia were developed actively from the epithelial tissues of seminiferous tubules. 2) Maturing phase (from Hay to early June): GSI levels increased rapidly in both sex. Oocytes at various developmental stages were observed. Appearance of active spermatogenesis were observed. 3) Mature and spawning phase (from June to August): High values of GSI remained static and oocytes accumulated significant quantitis of yolk globules. 4) Degenerating phase (from September to November): GSI levels decreased and ovaries were filled mostly with oocytes at the perinucleolus stage. Hepatic cells accumulated significant amounts of lipid droplets. 5) Resting period (from December to March) : Low values of GSI were kept and the size of oocytes at the perinucleolus stage did not increase. Spermatogenesis was not observed.

• Korean Journal of Ecology and Environment
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• v.46 no.3
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• pp.395-408
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• 2013

Environmental condition can induce changes in early life-history traits in order to maximise the ecological fitness. Here I investigated how temperature change and variation in human aquatic activity/behaviour affect early life-history consequences in fish using a dynamic-state-dependent model. In this study, I developed a general fish's life-history model including three life-history states depend-ing on foraging activity, such as body mass, mass of reproductive tissue (i.e., gonadal development) and accumulated stress (i.e., cellular or physiological damage). I assumed the level of foraging activity maximises reproductive success-ultimately, fitness. The model predicts that growth rate, development of reproductive tissues and damage accumulation are greater in higher temperature whereas higher human aquatic activity rapidly reduced the growth rate and development of reproductive tissue and increased damage accumulation. While higher foraging activity in higher temperature is less affected by human aquatic activity, the foraging activity in lower temperature rapidly declined with human aquatic activity. Moreover, lower survival rate in higher temperature or human aquatic activity was independent on mortality rate due to human aquatic activity or mortality rate when foraging activity, respectively. However, the survival rate in lower temperature or human aquatic activity was dependent on these mortality rates. My findings suggest that including of early life-history traits in relation to climate-change and human aquatic activity on the analysis may improve conservation plan and health assessment in aquatic ecosystem.

• The Korean Journal of Malacology
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• v.31 no.1
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• pp.21-26
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• 2015

This study histologically describes the gonadal development and reproductive cycle of the abalone, Haliotis discus discus inhabiting Jeju Island of Korea. Gonads displayed histologically definitive seasonal changes. The gonad index (GI) of both females and males was the highest (3.2 and 3.3) in September and was the lowest (1.7 and 1.4) in January and February. Egg diameter increase from early stage in March and reach about $180{\mu}m$ to ripe stage in August. The condition index (CI) was highest in July and lowest in May. The pattern of changes in the GI, egg diameter and CI were similar to the pattern of seasonal changes in gonadal tissues. The female ratio (F/F + M) was 59% (n = 182:127). The reproductive cycle was divided into an inactive stage (January-February), early active stage (March-April), late active stage (May-July), ripe stage (August-October) and spent and degenerative stage (November-January). The main spawning period of H. discus discus was August to October at Jeju Island in 2014.