• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.285-286
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• 2003

Vitelllogenin(Vg) is a sex specific protein appearing in the blood of sexually maturing female fish as well as other oviparous vetebrates. It is synthesized in the liver in response to estradiol-l7$\beta$(E$_2$). Although E$_2$ is a main induce. of Vg synthesis, other hormonal requirements have also been reported to be important in Vg synthesis(lazier et al., 1996; Peyon et at., 1997). (omitted)

• Clinical and Experimental Reproductive Medicine
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• v.29 no.4
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• pp.279-285
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• 2002

Objective : To evaluate the difference between estrogen only therapy and estrogen-androgen combination therapy in surgical menopause patients. Materials and Method: Surgical menopause patients received 0.625 mg conjugated equine estrogens or 0.625 mg conjugated equine estrogens plus 1.25 mg methyltestosterone for 2 years. Bone mineral density, menopausal symptoms, lipoprotein profiles were measured. Results: Both groups showed increased bone mineral density. In the combination group, total cholestero l, high density lipoprotein cholesterol and triglycerides decreased. In the estrogen only group, low density lipoprotein cholesterol decreased but high density lipoprotein cholesterol increased significantly. In both groups, menopausal symptoms were much improved. Side effects were easily tolerated in both groups. Conclusions: Estrogen-androgen combination therapy had comparable benefits compared with estrogen only therapy.

• Journal of Aquaculture
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• v.9 no.2
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• pp.141-149
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• 1996

Effects of $17{\alpha}$-methyltestosterone ($17{\alpha}-MT$) in rearing water on sex reversal of Nile tilapia (Oreochromis niloticus) were investigated and optimum conditions as initial treatment time, concentrations and treatment durations of hormone were evaluated in this study. For the study of the optimum initial treatment time, 0 to 20-day-old fry were treated by immersion in a 500 ppb solution of $17{\alpha}-MT$. Desirable results were obtained at 12-day-old fish as $86.4\%$ of male induction rates and this frequency was obviously higher than the other age groups. Twelve-day-old fry were immersed in $17{\alpha}-MT$ solutions at concentrations of $0\~2,000$ ppb for 24 hours for the study of dose dependent relationship between sex ratios and concentrations of $17{\alpha}-MT$, Male induction rates of all treated groups were higher than $80\%$, $X^2$ values against the sex ratio of control group indicate that sex reversal has taken place effectively in all experimental groups (P<0.001). Futhermore, 500 ppb treated groups showed highest male incidence of $86.4\%$. Effects of 5 different durations (0, 12, 18, 24 and 30 hours) treated with 1,000 ppb of $17{\alpha}-MT$ were also evaluated. Male induction rate from 0 to 24 hours treated group was increased with treatment durations. However, male incidence of 30-hour treated group ($84.0\%$) was sligthly decreased compare to the 24-hour treated group ($85.2\%$). It is concluded that immersion treatment using $17{\alpha}-MT$ on O. niloticus is possible on sex reversal at low concentration of 500 ppb and short treatment durations within 24 hours with 12-old-day fry.

• Journal of Aquaculture
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• v.9 no.2
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• pp.125-132
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• 1996

A study was carried out to test sex ratio of the progeny that were induced by the artificial fertilization between normal female and gynogenetic diploid eggs and sex-reversed gynogenetic diploid male sperm. Sex reversed gynogenetic diploid males were produced successfully in gynogenetic diploid female by immersion treatment with $17{\alpha}$-methyltestosterone at the concentration of 10 pub from $13.5{\pm}0.22$ mm to $57.6{\pm}5.1$ mm in total length. In $F_1$ progeny test, matings between normal females and sex-reversed gynogenetic males were not produced all female, but matings between gynogenetic diploid females and sex-reversed gynogenetic males were produced all female populations in six out of eight groups and two lots produced $96.9\%$ and $95\%$ female. These data showed that all-female populations were produced by crossing between gynogenetic diploid female and sex reversed gynogenetic diploid male.

• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.355-355
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• 2004

난생 경골어류의 성분화는 내인성 및 외인성 성스테로이드 호르몬의 영향을 받는 것으로 알려져 있지만, 해산 태생 경골어류의 성분화 과정에서 성스테로이드 호르몬의 작용은 아직 명확하게 밝혀져 있지 않다. 본 연구에서는 유용 양식어종의 하나인 해산 태생어류 조피볼락 Sebastes schlegeli를 대상으로 이 종의 성분화에 미치는 성스테로이드 호르몬의 영향을 조사하였다. 실험에 사용한 조피볼락은 출산후 일령 45일 전후의 성이 미분화한 개체들이었다. 실험어는 3개 실험군으로 나누어 (각각 3반복), 1개월간 각각 estradiol-l7${\beta}$ 또는 methyltestosterone을 처리하였고, 하나의 실험군은 호르몬 처리를 하지 않았다 처리기간 동안에는 각 실험군으로부터 무작위 sampling을 실시하여, 호르몬 처리에 따른 체내 성스테로이드 호르몬 변화를 조사하였으며, 각 실험군의생식소 분화과정을 조직학적으로 조사하였다. 성스테로이드 호르몬은 diethylether로 추출한후, rndioirmmunoassay 방법 (RIA)으로 분석하였다. 실험결과 대조구의 실험어는 1:1의 자연성비에 부합하는 성분화 결과를 나타내었지만, estradiol-17${\beta}$ 처리구는 자성화, methyltestosterone 처리구는 웅성화하는 경향을 나타내었으며, 이러한 성분화 shift는 외부에서 투여한 호르몬이 실재 내부호르몬양의 변화를 초래하여 이루어졌음이 RIA 분석에 의해 부분적으로 확인되었다. 본 연구의 결과는 해산 태생 경골어류의 성분화 역시 성스테로이 드호르몬의 작용에 의하여 매개 또는 조절되어진다는 사실을 제시한다. 하지만 태생어류에서 이 호르몬의 실질적 작용 메카니즘 및 명확한 작용시기에 대해서는 보다 많은 연구가 요구되어 진다.을 설계하는 것이 가능하였다.적(最適) 온도(溫度)는 $30^{\circ}C$, avicelase와 ${\beta}-glucosidase$의 최적(最適) pH는 5.0, CMCase는 pH 5.5 이었으며, 균사(菌絲) 생육(生育)은 pH 5.0에서 양호(良好)하였다. 배양(培養) 기간(期間)은 avicelase가 8일(日), CMCase가 10일(日), ${\beta}-glucosidase$는 16 일간(日間) 배양(培養)하였을 때 최대치(最大値)를 보였고, 균사(菌絲) 생육(生育)은 12일(日) 배양(培養)했을 때 가장 양호(良好)하였다.가한 반면, 중국인들은 고소한 향의 강도, 고소한 향의 기호도, 전체적인 맛에서 뚜렷하게 일본참기름을 우수하게 평가하였다.s의 항체(抗體)로 반응(反應)시킨 후 protein-A gold(15 nm)로 표식(標識)시킨 바 제일 바깥 상층(上層)의 keratinocyte에 있어서 세포막표면(細胞膜表面)을 따라 표식(標識)되어 세포막항원(細胞膜抗元)을 나타내었으며, 이와 같은 소견(所見)으로 미루어 정상피부(正常皮膚) 중층편평상피세포(重層扁平上皮細胞)에서도 동일(同一)한 소견(所見)을 관찰(觀察)할 수 있다고 본다.al remnants, Resorption of fetus로 관찰된 것이다. Fetal death는 수정후 $14{\sim}18$일까지의 사망으로써 Maceration of fetus로 관찰되는 것이다. 통계학적 분석은 각 Group의 착상 을과 자궁 내 사망 율을 산출할 때에는 각 임신마우스에 따라 발생빈도가 크게 다르기 때문에 통계처리에는 Non parametric 검정인 Kluskal Wallis 검정을 사용하여 분석하였다. 또한 개체 Level 영향인 착상을, 태아사망,

• Journal of Aquaculture
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• v.8 no.2
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• pp.141-148
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• 1995

For the mass production of all-female triploid rainbow trout during fall season, treatment of short-term daylength from 30th of August, 1994 and chromosome manipulation by heat shock were performed with 3-year-old fish. After treatment of short-term daylength to fish, we successfully obtained the fertilized eggs from all treated fishes. However, hatching rate were significantly lower than that of natural spawning season (P<0.05). Hormonal treatment using 3mg of $17\alpha-methyltestosterone$ per kg of diet for 55 days at $16.5^{\circ}C$ gave $100\%$ of sex-reversed male (masculinized female) population. When the fertilized eggs were treated with the various conditions of heat shocks survival rates and triploid incidencies were varied, and ranged from 15.0 to $88.2\%$ and 36.7 to $100\%$, respectively.

• Journal of Aquaculture
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• v.10 no.2
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• pp.179-187
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• 1997

Early development growth and sexual phenomena of the hybrid between male spotted flounder (Verasper variegatus) and female olive flounder (Paralichthys olivaceus) were investigated. The hybrid produced was newly called the "Bumnupchi" in Korean name, "Mottled flounder" in English name. Fertilization rate, hatching rate and early survival rate of the mottled flounder were 56.9~72.3%, 86.7~92.5% and 89.1~96.0%, respectively. At 50th day and 240th day after hatching, they were 2.1$\pm0.2cm\;and\;22.9\pm2.1cm\;in\;total\;length, \;0.10\pm0.002g\;and\;179.0\pm38.5g$ in body weight, respectively. Eye position of the mottled flounder was mixed with both dextral (77.7%) and sinistral type (22.3%). Gonads were differentiated into ovarian type and testis type at 80th day after hatching, and its ratio was 1:1 (P>0.05). Most Gonads seemed to be sterile without having germ cell, whereas only 3.6% of investigated indiciduals turned out to have oocytes in the gonad. When the induction of sex reversal were attempted by daily oral administration of $17\beta$-methyltestosterone (0.5mg/kg fish) andestradiol-17$17\beta$(0.5mg/kg fish)from 40th to 100th day after hatching, both testis and ovary type were induced 81.9% and 87.7% of each hormone-treated fish, respectively.fish, respectively.

• 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.

• Journal of Aquaculture
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• v.9 no.1
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• pp.19-23
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• 1996

Hormonal induction of sex reversal was examined by using sex steroid hormones in serranid fish, Epinephelus septemfasciatus. Young fish were collected from the coastal area of Cheju Island, and reared for 2 years before fish were used for the experiments. Without any hormonal treatment, gonads of fish ($1,000\~2,800$ g in body weight) were occupied by oocytes of the perinucleolus stage and bundles of protogonial cells in the area of germinal epithelium. When the induction of sex reversal was attempted by daily oral administration of $17\alpha$-methyltestosterone (0.5 mg/kg fish) for 90 days, active spermatogenesis was induced, and spermatogonia and spermatocytes and spermatids were appeared in all gonads we examined. However, after daily, oral treatment of $17\beta$-estradiol (0.5 mg/kg fish) to. 50 days with the following injection of human chorionic gonadotrophin ($1,000\~1,500$ IU/kg fish) mature oocytes were not induced in fish gonad.

• Korean Journal of Animal Reproduction
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• v.20 no.3
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• pp.259-269
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• 1996

To establish whether or not androgens is responsible for the induction of vitellogenin(Vg) synthesis and secretion, primary hepatocytes prepared from immature eels were used. The results are follows: 1. Eel hepatocytes were prepared using a collagenase perfusion technique. The isolated cells attached efficiently to fibronectin-coated dishes and subsequently formed monolayers in serum-free medium. These cultures maintained in medium for 10 days with minimal cell loss. 2. Estradiol-17$\beta$(E2) alone was insufficient to induce Vg synthesis. The combination of E2 with methyltestosterone(MT) markedly stimulated Vg synthesis. High vg production occurred in MT concentration from 10-6~10-5M in the presence of E2 (10-6M). Testosterone and androsterone were also effective, but progesterone was not effective in inducing Vg synthesis. Neither MT alone nor testosterone and androsterone alone had any effect on Vg synthesis. 3. E2-primed hepatocytes showed Vg synthesis in both media with and without hormones 1 day after culture. In the cultures with the vehicle, MT, or progesterone, the rate of synthesis seemed to decrease with time. But the combination of E2 and MT showed an intense increase in Vg synthesis. Hepatocytes isolated from E2-primed eels also required androgens for continuating of Vg synthesis. 4. These results demonstrate that androgens act together with E2 in synthesis and secretion of eel Vg.