• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.3
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• pp.167-176
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• 1991

Sexual maturation of the bluespotted mud hopper, Boleophthalmus Pectinirostris(Linnaeus) was investigated histologically on the gonadal development, and studied by gonadosomatic index(GSI), egg diameter composition. Samples were collected in the intertidal zone of Wolyon-ri, Hoihyon-myon, Okku-gun, Chollabuk-do, Korea, from April to October in 1988 and from June to August in 1989. The ovary is a pair of sac-shaped organ. The testis is a pair of tubule-shaped organ and it is connected to the seminal vesicle which is located at the posterior end of the testis. In male and female, GSI began to increase from late May when the water temperature began to increase and reached the maximum value in June and July, respectively. It began to decrease from August, the highest water temperature season. Thereafter, maintained relatively low values until October. The annual reproductive cycle of this species could be classified into four sucessive developmental stages: growing stage$(April{\~}May)$, mature stage$(June{\~}early\;July)$, ripe and spent stage(late lune-early August), degenerative and resting stage$(late\;August{\~}March:\;the wintering\;period)$. According to the frequency distributions of egg diameters in the spawning season, Boleophthalmus Pectinirostris was species to spawn twice or more in the spawning season.

• Development and Reproduction
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• v.9 no.2
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• pp.95-103
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• 2005

Reproductive cycle, gonadosomatic index(GSI), egg diameter composition, first sexual maturity, sexually matured length(50% of first sexual maturity), and sex ratio of Amusium japonicum japonicum, were investigated by histological observations and morphometric data. Samples were collected monthly from the subtidal zone of Sogwipo, Jejudo, Korea, for two years. The sun and moon scallop Amusium japonicum japonicum is dioecious. Monthly variation in the GSI showed similar patterns with the reproductive cycle. Ripe oocytes were about $70{\sim}90\;{\mu}m$ in diameter and had thick egg membranes. The spawning period was from November to January, and the main spawning occurred between November and December when the seawater temperature was relatively low. From monthly changes in egg diameter composition, the spawning period was once a year, although the number of spawning frequencies is assumed to occur more than twice during the spawning season. The reproductive cycle of this species could be divided into five successive stages: early active stage(April to June), late active stage(June to September), ripe stage(October to November), spawning stage(November to January), and spent/resting stage(February to April). First sexual maturities in female and male scallops ranging from 85.1 to 90.0mm in shell length were over 50% and they were 100% for scallops over 90.0mm in shell length. In this population, sexually matured shell lengths(50% of rate of group maturity) in females and males were 86.96 and 86.59mm, respectively. The female to male sex ratio among individuals over 85.1mm in shell length was not significantly different from 1:1($X^2=0.18$, p>0.05). No evidence of hermaphrodite was found in histological sections of any scallop examined.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.1
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• pp.13-16
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• 2001

Plasma levels of sex steroid hormones in rockfish, Sebastes inermis were examined monthly in relation to gonadosomatic index (GSI) under a controlled water temperature and photoperiod, The GSI of a control group (C) in female began to increase from November and reached a maximum in January, Sample fish under a controlled water temperature and photoperiod (Tr) were divided into a responded group (Tr-r) and a un-responded group (Tr-n) by the gonadal maturation condition and GSI. The GSI of females in Tr-r reached a maximum in March. But the female GSI in Tr-n kept lower than 1.2 during the experimental period. No differences in male GSI were noticed between C and Tr. The $estradiol-17\beta$ and testosterone levels of female plasma in Tr reached a maximum in October, later than those in C. In males, these was no difference in 11-ketotestosterone and testosterone between C and Tr. When rockfish was reared in September under the controlled water temperature and photoperiod which were equivalent to those in July, that is two months earlier, the maturation of females was delayed in comparison with C. This finding suggested that delayed maturation in ovary was caused by the secretion of sex steroid hormones in relation to the water temperature and photoperiod of the hypothalamus-pituitary-gonad axis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.373-377
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• 2000

This study Investigated the effects of $estradiol-l7{\beta} (E_2)$, $17{\alpha}-methyltestosterone$ (MT) and high temperature (WT) on gonadal sex differentiation in black rockfish, Sebastes srhlegeli. fish were reared to oral adminstration of E, at nominal concentrations of $20, 40 and 60 {\mu}g/g diet$, and MT at nominal concentration of 20 and $50 {\mu}g/g$ diet from 56 days to 77 days after parturition. In the treatment of WT, water temperature of the breeding tanks ranged $27.0{\pm}0.5^{\circ}C$ more than $10^{\circ}C$ approximately, in comparison to the control and other experimental group, In the process of sex differentiation until 56 days after parturition, gonads were composed of mostly gonia cells, sexually undifferentiated. In contrast, 128 dal's after parturition, the ovaries were composed of ovarian cavity and lamellae, and oogonia and perinucleolus oocytes were distributed in the lamellae of ovary, and the testes were composed of a number of seminiferous tubule, and spermatogonia were distributed in the seminiferous tubule, and also melanophore scattered in the matrix layer of testis. In the sex ratio, more females than male were observed from $E_2$. treatment groups when compared to the control, but more males than females were observed from MT and WT treatment groups when compared to the control. In the results of the present study, the concentration and kinds of the sex steroid hormones, and also the rearing high temperature caused to the factor of sex determination in the process of sex differentiation of black rockfish.

• Development and Reproduction
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• v.22 no.1
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• pp.85-94
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• 2018

Endocrine disruptors have been concerned in toxicology but now challenged as physiological point especially concerned with exposing dose and period. In this study the low-dose chronic administration of di(2-ethylhexyl) phthaltae (DEHP) during reproductive period was examined to evaluate the possible roles. Adult male and female CD-1 mice were exposed to DEHP with drinking water containing $133{\mu}g/L$ and $1,330{\mu}g/L$ DEHP in water according to OECD 433 guide line and sacrificed just after weaning. The weights of uterus and ovary were decreased by drinking of $1,330{\mu}g/L$ DEHP water. There was not adverse effects on either accumulated mating rate and mating rate depend on estrus stage, pregnancy duration, and sex ration at birth. However, the accumulated rate of successful delivery and litter size were significantly high at $1,330{\mu}g/L$ DEHP water. The number of epididymal sperm was significantly increased by drinking of $1,330{\mu}g/L$ DEHP water. In addition, the number of follicles (primary, secondary, tertiary) were more many than control at $1,330{\mu}g/L$ DEHP water drunk mother. Though further studies are needed to identify what are the mechanism of DEHP in folliculogenesis and spermatogenesis. From this study we firstly report the effect of low-dose chronic administration of DEHP with drinking could change the ovarian follicle population size and spermatogenesis rate. Put together, those finding is different from previous high-dose effects and suggest the physiological role of DEHP in gonads and uterus.

• The Korean Journal of Malacology
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• v.25 no.2
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• pp.105-112
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• 2009

We investigated the degree of obesity, histological development stages of gonads and sexual maturation induction rates of comb pen shell, Atrina pectinata, per the type of micro-algae supplied. Terms of maturation by singular or mixed supply of microalgae, it was found that maturation of the female was the quickest at 60.0% by the Tetraselmis tetrathele (Tet). experiment group followed by 57.1% by the Chlorella ellipsoidea (Chl). experiment group and 16.7% by the Phaeodactylum tricornutum (Pha). experiment group. However, there were no significant differences between Tet. experiment group and Chl. experiment group. As for the male, maturation was the quickest at 60.0% by the Tet. experiment group followed by 16.7% by the Chl. experiment group and 14.3% by the Pha. experiment group. In light of these results, Tet. is concluded to be a very useful feed organism in breeding the mother comb pen shells. Upon completion of the experiment, the sexual maturation induction rate for the female was found to be the highest at 82.0% in the Tet. experiment group followed by 72.0% by the Chl. experiment group, 64.0% by the Pha. experiment group and 58.0% by the mixed micro-algae experiment group. During the period of experiment, the survival rate was the highest at 94.4% by the mixed micro-algae experiment group followed by 90.0% by the Pha. experiment group, 83.1% by the Tet. experiment group and 78.8% by the Chl. experiment group.

• Journal of Aquaculture
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• v.21 no.4
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• pp.331-338
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• 2008

Monthly changes in the gonadosomatic index (GSI) and hepatosomatic index (HSI) of wild river puffer Takifugu obscurus, and water quality environment in spawning area during breeding season were investigated from March 1995 to February 1996. Monthly changes in GSI and HSI of T. obscurus, that was cultured in low salinity, were calculated. The external morphology of the gonads, germ cell differentiation during gametogenesis and the reproductive cycle with the gonad developmental phases were investigated by histological analysis. The optimum water quality environment in Ganggyung, Choongcheongnam-do, where is spawning ground of wild T. obscurus, was $15-20^{\circ}C$ (water temperature) and 0 psu (salinity). Monthly changes in the GSI in females and males reached a maximum in May, and then rapidly decreased. Therefore, it is assumed that in the natural condition the spawning period of wild T. obscurus is May to June. In females and males, it showed a negative correlationship between the GSI and HSI. The external morphology of the gonads in female and male T. obscurus, that was cultured in low salinity, is composed of a pair of saccular structure. Based on monthly changes in the GSI, it is assumed that in female T. obscurus, that was cultured in low salinity, spawn from March through May. Therefore, it showed a negative correlationship between changes in the GSI and HSI. On the whole, in females and males, it showed a similar pattern between wild and cultured T. obscurus. The reproductive cycle with the gonad developmental phases can be classified into successive five stages in females: the early growing stage, late growing stage, mature stage, ripe and spent stage, and recovery and resting stage. In males, that can be divided into successive four stages: the growing stage, mature stage, ripe and spent stage, and recovery and resting stage. In case of wild T. obscurus, the spawning period has once a year, however, those cultured in the high water temperature ($20-27^{\circ}C$) - low salinity (under 3.3 psu) condition have reproductive characteristics having possibilities of discharge of eggs and sperms year-round as a multiple spawner.

• Childhood Kidney Diseases
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• v.6 no.2
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• pp.155-168
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• 2002

Purpose; Systemic lupus erythematosus(SLE) is an autoimmune disease with multi-system involvement and renal damage is a major cause of morbidity and mortality in children. Renal involvement is more common and severe in children than in adults. Therefore, renal biopsy plays a crucial role in planning effective therapy. In this study, we investigated the clinical and pathological findings of lupus nephritis in children to aid clinical care of the disease. Methods: The clinical and pathological data of 40 patients who were diagnosed as SLE with renal involvement in Shinchon Severance Hospital from Jan. 1990 to Sep. 2002 were analyzed retrospectively. Results: The ratio of male to female patients was 1:3 and the median age at diagnosis was 12.1(2-18) years old. FANA(95.0%), anti-ds DNA antibody(87.5%), malar rash(80.0%) were the most common findings among the classification criteria by ARA. Microscopic hematuria with proteinuria(75.0%), nephrotic syndrome(55.0%), and microscopic hematuria alone(15.0%) were the most common renal presentations in the respective order at diagnosis. There were 27 cases with WHO class IV lupus nephritis confirmed by renal biopsy and 3 cases with pathological changes of WHO class type. Different treatment modalities were carried out : prednisolone only in 5 cases, prednisol-one+azat-hioprine in 9 cases, prednisolone+azathioprine+intravenous cyclophosphamide in 14 cases, prednisolone+cyclosporine A+intravenous cyclophosphamide in 12 cases, plasma exchange in 9 cases and intravenous gamma-globulin in 2 cases. The average follow-up period was $51.8{\pm}40.5$ months. During $51.8{\pm}40.5$ months. During follow-up, 4 patients expired. The risk factors associated with mortality were male, WHO class IV and acute renal failure at diagnosis. Conclusion: Renal involvement was noted in 63.5% of childhood SLE, and 67.5% of renal lesion was WHO class IV lupus nephritis which is known to be associated with a poor prognosis. Therefore aggressive treatment employing immunosuppressant during the early stages of disease could be helpful in improving long-term prognosis. But careful attention should be given to optimize the treatment due to unique problems associated with growth, psychosocial development and gonadal toxicity, especially in children.

• Journal of Aquaculture
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• v.11 no.4
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• pp.475-485
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• 1998

To clarify annual reproductive cycle of Koran dark sleeper, odontobutis platycephala, we examined the seasonal changes of gonadosomatic index(GSI), testicular development stages and sex steroid hormones in blood from December 1995 to November 1997. Testis was podlike shape from July to October, and tadpole-like shape from November because of its expanded posterior part. GSI was 0.14~0.18 from July to September and increased to $0.43{\pm}0.04$ in October and then was not changed significantly until February. GSI was reincreased to $0.52{\pm}0.09$ from March and then was kept at similer levels until May, but fell down to $0.28{\pm}0.05$ in June. As results of histological observation, testis was divided into 3 parts(anterior, boundary, posterior) in the development progress of germ cells. In July, the testis was composed of only spermatogonia without seminiferous tubules in most fishes. In the anterior part of testis, the ferquency of spermatogenesis stage seminiferous tubules appearing in August was more than 80% from September to December. decreased gradually from January to March and drastically in April, and then disappeared in June. The frequency of spermiogenesis stage seminiferous tubules appearing in December, increased gradually from January to March and drastically to 80% in April, and reached to 90% the highest levels of the year in June. Post-spawning stage seminiferous tubules did not appear throughout the year. The frequency of spermatogonia was 100% and 65% in July and August, and less than 20% in the rest period of the year. In the boundary part, the frequency of spermatogenesis stage seminiferous tubules appearing in August increased from September and reached to 82% in November, decreased from December, adn disappeared in March. The frequency of spermiogenesis stage seminiferous tubules appearing in November was less than 18% until February, and increased to 29%~57% from March to June. The frequency of post-spawning stage seminiferous tubules appeared 12%~25% only from March to June. The frequency of spermatogonia was 100% in July, decreased to 85% in August and 10% in November, and increased gradually from December to 50% in April, and decreased again from May to June. In the posterior part, seminiferous tubules with some seminiferous tubules increased drastically 80%~85% in August and September, decreased drastically from October to November and remained below 10% until February, and disappeared after March. The frequency of spermiogenesis stage seminiferous tubules appearing in August increased sharply from October and reached to 75% in November. decreased to 15% in December and no significant changes until March, and disappeared after April. The frequency of post-spawning stage seminiferous tubules appearing very early in November increased to 82% in December and 85%~95% until June. The frequency of spermatogonia was 100% in July, decreased drastically to 15% in August, disappeared from October to Mrch, but reappeared from April and kept at less than 10% until June. The blood level of testosterone (T) increrased gradually from August was $0.61{\pm}0.09 ng/m\ell$ in November, increrased drastically to $3.99{\pm}1.22 ng/m\ell$ in December and maintained at in similar level until March, and decreased to $0.25{\pm}0.14 ng/m{\ell} ~ 0.17{\pm}0.13ng/m{\ell}$ in April and May and no significant changes until July (P<0.05). The blood level of 17, 20 -dihydroxy-4-pregnen-3-one $ng/m{\ell}$in the rest of year without significant changes(P<0.05). Taken together these results, the germ cell development of testis progressed in the order of posterior, boundary, anterior part during annual reproductive cycle in Korean dark sleeper. The testicular cycle of Korean dark sleeper was as follows. The anterior part of testis : i.e. spermatogonial proliferation period (July), early maturation period (from August to November), mid maturation period (from December to March), late maturation period (from April to May) and functional maturation period (June) were elucidated. The boundary of testis, i.e. spermatogonial proliferation period (July), early maturation period (from August to October), mid maturation period (from November to February) and the coexistence period of late maturation, functional maturation and post-spawn (from March to June) were elucidated. The posterior of testis, i.e. spermatogonial proliferation period (July), mid maturation period (from August ot September), late maturation period (October), functional maturation period (November) and post-spawn period (from December to June) were elucidated. It was showed that the changes of sex steroid hormone in blood played a important roles in the annual reproductive cycle of Korean dark sleeper.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.206-218
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• 1984

The gonadal development and gametogenesis of shad, Konosirus, punctatus (TEMMINCK et SCHLEGEL) were studied by comparing with various quantitative indices, such as seasonal changes of gonadosomatic index, fatness, egg-diameter composition, first maturing size, and by comparing with histological changes of gonad and gonadotrophs(GTH) in pituitary. The materials were monthly sampled from Dadaepo at the estuary of the Nakdong river in Korea from September, 1982 to October, 1983. The ovary of shad is a pair of sac-shaped organs revered with a fibromuscular capsule and consisting of numerous sacs. The type of testicular structure is lobular type with development of germ cells, mesenchymal tissue on the lobuli. The gonadosomatic index (GSI) is rather low till March, but increases in April and reaches to peak in June in females and May in males. And it suddenly falls in July. The gonads become active on the increase of water temperature and spawning season ends before high water temperature. After spawning, the small oocytes continue to remain as they are untill the growing period next year. The reproductive cycle includes the successive stages of growing from March to April, mature from April to May, ripe and spawning in June, and recovery and resting from July to February next year. In egg-diameter composition of an ovary taken in the spawning season, 2-3 modes were recognized with some batches shown in an ovary. An individual shad spawns twice or more in a month-spawning season. The individual spawning interval is estimated to be ten days or less. Changes of fatness are corelated with those of water temperature that affect on the condition of feeding, but less corelated with spawning. The percentage of mature of female and male fish, are $50\%$ in 17.0-18.0 cm and $100\%$ in 18.0-19.0 cm. GTH cells are activated from growing period and decrease their activity at pre-spawning season with peak activity for mature period.