• Fisheries and Aquatic Sciences
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• 제4권2호
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• pp.70-74
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• 2001

To examine the production of steroids with potential oocyte maturation-inducing activity in the spotted flounder, Verasper variegatus, we have incubated post-vitellogenic oocytes (0.82­0.95mm in diameters) with radiolabeled pregnenolone and $17\alpha-hydroxyprogesterone$. The resulting metabolites were analyzed by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). The two main metabolites (progestogens) found in both incubations co-migrated with $17\alpha-hydroxy$, $20\alpha-dihydroprogesterone$ $(17\alpha, 20\alpha OHP)$ and $17\alpha-hydroxy,\;$20\beta-dihydroprogesterone$ (17 a20{30HP). Additional chromatography by HPLC and TLC confirmed the presence of radioactive $17\alpha, 20\alpha OHP$ and a large amount of unknown metabolite. The present study did not reveal in vitro formation of $l7\alpha 20\beta OHP$. Although 1$l7\alpha 20\beta OHP$ was found in a small amount, the synthesis of this steroid suggests that it may play a role in regulating the oocyte maturation process in the spotted flounder.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 1998년도 제3차 심포지움
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• pp.17-19
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• 1998

• 한국발생생물학회지:발생과생식
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• 제12권1호
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• pp.107-112
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• 2008

점망둑의 난모세포 성숙과정에서 생성되는 주요 성 스테로이드 호르몬, $C_{21}$-스테로이드를 분석하고자 전구물질 $^3H-17{\alpha}hydroxyprogesterone$ ($^3H-17{\alpha}OHP$)를 성숙기 난모세포(난경 $0.74{\sim}0.97\;mm$) 배양초기에 첨가하여 24시간 배양하였다. 스테로이드 대사물질 분석과 동정은 thin layer chromatography와 gaschromatography-mass spectrometry로 이루어졌다. $^3H-17{\alpha}20{\alpha}P$로부터 생성된 주요 성 스테로이드 대사물질은 $17{\alpha}$-hydroxy, $20{\alpha}$-dihydroprogesterone ($17{\alpha}20{\alpha}P$)와 $17{\alpha}$-hydroxy, $20{\beta}$-dihydroprogesterone ($17{\alpha}20{\beta}P$)로 확인되었다. 이들 대사물질은 난경 0.80 mm 이상에서 관찰되었으며, GVBD (germinal vesicle breakdown) 유도 효능 테스트에서 점망둑의 난모세포는 $17{\alpha}20{\beta}P$에 더 민감하게 반응하였다. 이러한 결과는 점망둑의 난소성숙 과정에 $17{\alpha}20{\alpha}P$와 $17{\alpha}20{\beta}P$이 모두 관여하나, MIS (maturation inducing steroid)로서의 가능성은 $17{\alpha}20{\beta}P$이 더 큰 것으로 관찰되었다.

• 한국양식학회지
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• 제20권3호
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• pp.154-159
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• 2007

Manchurian trout (Brachymystax lenok) is an endangered fish species in East Asia including the Korean peninsula. To establish a method for artificial propagation and to improve our understanding of the reproduction in the species, we have produced recombinant gonadotropins, follicle-stimulating hormone (r-mtFSH) and luteinizing hormone (r-mtLH), which may play central roles in reproductive activities. In the present study, the biological activities of the recombinant hormones were analyzed by gonadosomatic index (GSI), ovarian follicle diameter, and sex steroid levels in mature rainbow trout (Oncorhynchus mykiss). In the 6th day post-injection, FSH-injected fish were slightly decreased in the GSI value, although there were no significant differences among those of control, r-mtFSH, and r-mtLH treatments. Injection of the r-mtFSH increased follicle diameters significantly as compared with those of control- and r-mtLH-injected fish. The plasma steroid levels showed wide differences in the groups at 1, 3, or 6th day post-injection. Despite the variable steroid levels, three individuals receiving either r-mtFSH or r-mtLH showed a great increase in a maturation-inducing steroid, $17{\alpha},20{beta}$-dihydroxy-4-pregnen-3-one, at 3 and 6 days. Taken together, these results suggest that biological efficacies of the recombinant FSH and LH should be further studied in the Manchurian trout.

• 한국발생생물학회지:발생과생식
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• 제16권1호
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• pp.39-45
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• 2012

To verify the sex steroids which are involved in oocyte maturation of the blacktip grouper, $Epinephelus$ $fasciatus$, we incubated vitellogenic oocytes (0.41 and 0.50 mm in average diameter) in the presence of exogenous steroid precursor ($[^3H]17{\alpha}$-hydroxyprogesterone). Steroids were extracted, separated and identified by thin layer chromatography. The major metabolites produced were androstenedione, estradiol-$17{\beta}$, estrone and progestogens. Progestogen metabolites in the oocytes of 0.50 mm were more abundant than those of 0.41 mm. Also, we investigated the $in$ $vitro$ effects of human chorionic gonadotropin (HCG; 5, 50 and 500 $IU/m{\ell}$), $17{\alpha},20{\beta}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}P$) and $17{\alpha},20{\beta}$-trihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}21P$; 5, 50 and 500 $ng/m{\ell}$, respectively) on oocyte maturation. In the oocytes of 0.41 mm, treatment with 50 IU HCG stimulated GVBD ($55.30{\pm}1.20%$) compared with controls ($32.41{\pm}3.13%$, $p$<0.05). In the oocytes of 0.50 mm, treatment of $17{\alpha}20{\beta}P$ (50 and 500 $ng/m{\ell}$) stimulated GVBD ($50.13{\pm}2.52$ and $51.77{\pm}5.91%$, respectively) compared with controls ($36.81{\pm}2.89%$, $p$<0.05). Treatment with 500 IU HCG also stimulated GVBD ($49.59{\pm}5.15%$) compared with controls ($p$<0.05). Taken together, these results suggested that both HCG and $17{\alpha}20{\beta}P$ were effective on in vitro oocyte maturation and $17{\alpha}20{\beta}P$ may act as a maturation inducing hormone in blacktip grouper.

• 한국수산과학회지
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• 제48권4호
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• pp.483-488
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• 2015

We studied oocyte steroidogenesis in the blackfin flounder Glyptocephalus stelleri as a region-specific species, in the East Sea of Korea during the spawning season. Maturing oocytes (0.76, 0.82, 0.88, and 0.91 mm in oocyte diameter) were incubated in vitro in the presence of [$^3H$] $17{\alpha}$-hydroxyprogesterone ($[^3H]17{\alpha}$-OHP) as a precursor. Steroid metabolites were extracted from the incubated medium and oocytes, and the extracts were separated and identified by thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) and gas chromatographymass spectrometry (GC/MS). The major metabolites produced from $[^3H]17{\alpha}$-OHP were androgens [androstenedione (A4) and testosterone (T)] and estrogens [$17{\beta}$-estradiol (E2) and estrone (E1)] and progestins [$17{\alpha},20{\alpha}$-dihydroxy-4-pregen-3-one ($17{\alpha}20{\alpha}P$) and $17{\alpha}20{\beta}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}P$)] in maturing oocytes. The metabolic rate of $17{\alpha}20{\beta}$ was elevated (29.04%) in oocytes measuring 0.88 mm (nucleus migration stage following the induction of germinal vesicle breakdown), but was very low in oocytes measuring 0.76, 0.82, and 0.91 mm (0.42, 0.67, and 2.62%, respectively). From these results, we suggest that $17{\alpha}20{\beta}P$ acts as a maturation-inducing steroid in the blackfin flounder.

• 한국수산과학회지
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• 제39권5호
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• pp.391-397
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• 2006

This study correlated changes in estradiol-l7$\beta$ ($E_2$), testosterone (T), 17$\alpha$,20-dihydroxy-4-pregnen-3-one (DHP), and vitellogenin (VTG) levels with changes in the gonadosomatic index (GSI) and ovarian histology during the annual reproductive cycle of the wild marbled sole, Limanda yokohamae. Synchronous oocyte development occurs in this fish. Ovary maturity was classified into four periods, based on histological observations: the spawning (December to February), post-spawning (February to April), recovery (May to August), and vitellogenic (September to November) periods. Seasonal changes in the GSI were inversely correlated with water temperatures and reflected the degree of ovarian maturity. Plasma VTG levels were correlated with changes in the GSI, which increased from September to a peak in January, and levels remained comparatively high until February. Estradiol-17$\beta$ was at baseline levels (<0.11 ng/mL) during the spring and summer, and peaked rapidly (1.55$\pm$0.445 ng/mL) from October to January. Plasma T and DHP levels had a similar profile; they rose markedly during the spawning period and remained low (or were not detectable) from spring through autumn. These data indicate that changes in plsama steroid hormones and VTG levels are correlated with the annual ovarian activity of the marbled sole. Based on these results and published reports, it appears that in this species DHP is the most important maturation-inducing steroid and that T is also related to final maturation.

• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.421-426
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• 2013

In this study, oocyte steroidogenesis are investigated in relation to oocyte development in the starry flounder, Platichthys stellatus, a marine multiple spawner. Vitellogenic (0.52 and 0.55 mm oocyte diameter) and mature oocytes (0.63, 0.66 and 0.71 mm oocyte diameter) were incubated in vitro in the presence of $[^3H]17{\alpha}$-hydroxyprogesterone ($[^3H]17{\alpha}$-OHP) as a precursor. Steroid metabolites were extracted from the incubated media and oocytes, the extracts were separated and identified by thin-layer chromatography (TLC), high performance liquid chromatography (HPLC) and gas chromatographymass spectrometry (GC-MS). The major metabolites produced from $[^3H]17{\alpha}$-OHP were androgens [androstenedione ($A_4$) and testosterone (T)] and estrogens [$17{\beta}$-estradiol ($E_2$) and estrone ($E_1$)] and progestins [$17{\alpha},20{\alpha}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\alpha}P$) and $17{\alpha},20{\beta}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}P$)] in vitellogenic and mature oocytes. The results from this study suggest the potential roles of $E_1$ in the oocytes with diameter 0.52-0.71 mm, $17{\alpha}20{\alpha}P$ and $17{\alpha}20{\beta}P$ at the oocytes of 0.63, 0.66 and 0.71 mm.

• 한국수산과학회지
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• 제40권3호
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• pp.153-159
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• 2007

We studied oocyte steroidogenesis in relation to oocyte development in the greenling, Hexagrammos otakii, a marine multiple spawner. Vitellogenic and mature oocytes were incubated in vitro in the presence or absence of $[^3H]-17\;{\alpha}-hydroxyprogesterone$ as a precursor. The major metabolites were androgens [androstenedione $(A)_4)$ and testosterone (T)] and estrogens [$17\;{\beta}-estradiol\;(E_2)$ and estrone ($E_1$)] in vitellogenic oocytes. The metabolic rate of T was lower in 1.08 to 12-mm oocytes, while that of $E_2$ increased with oocyte size. The endogenous productions of T, $E_2$ and 17 ${\alpha}-hydroxy$, 20 ${\beta}-dihydroprogesterone\;(17{\alpha}20{\beta}OHP)$ were quantified using a radioimmunoassay in the non-precursor group. The endogenous levels of T and $E_2$ were highest in 1.08 to 12-mm oocytes and $17{\alpha}20{\beta}OHP$ was produced only in 1.90 to 95-mm oocytes. The relationship between oocyte size and steroidogenesis showed that 1.08 to 12-mm oocytes are full vitellogenic following induction of the maturation process. Moreover, $17{\alpha}20{\beta}OHP$ acts as a maturation inducing hormone in H. otakii.

• 한국양식학회지
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• 제11권1호
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• pp.119-124
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• 1998

농어의 난성숙과 배란유도를 위한 C하(21)-스테로이드와 HCG의 효능 비교실험이 in vitro에서 이루어졌다. 분리된 난모세포를 대상으로 17${\alpha}$-hydroxy, 20${\beta}$-dihydroprogesterone(17${\alpha}$20${\beta}$OHP), 17${\alpha}$-hydroxy, 20${\beta}$-dihydroprogesterone(17${\alpha}$20${\beta}$OHP : 5~100ng/ml)와 HCG(5~500IU/ml)를 사용하여 관찰한 난성숙 유도효과, 즉 GVM(germinal vesicle migration)과 GVBD(germinal vesicle breakdown)를 보면, 5ng/ml 농도의 17${\alpha}$20${\beta}$OHP와 17${\alpha}$20${\beta}$OHP를 제외한 모든 실험군에서의 반응은 대조군보다 효과가 있는 것으로 나타났으며, 특히 17${\alpha}$20${\beta}$OHP 50ng/ml 농도에서 가장 높은 성숙 유도효과를 보였다. GVBD 유도효과에 대한 17${\alpha}$20${\beta}$OHP(50ng/ml), HCG(50IU/ml) 그리고 이들 호르몬을 혼합처리한 17${\alpha}$20${\beta}$OHP+HCG에서는 혼합처리한 실험군이 가장 높은 반응을 보여 이들의 상호 보완적 작용을 관찰할 수 있었다. 난소조직을 대상으로 HCG와 17${\alpha}$20${\beta}$OHP를 사용하여 in vitro에서 농어의 배란유도효과를 관찰한 결과 사용한 모든 농도(17${\alpha}$20${\beta}$OHP : 1~1000ng/ml, HCG : 1~500IU/ml)에서 배란반응을 보였다. 특히 저농도 50ng/ml 또는 50IU/ml 이하로 처리하는 것이 더 효율적인 것으로 나타났다. 또한 HCG 처리가 17${\alpha}$20${\beta}$OHP보다 배란 반응에 더 민감하게 작용하는 것으로 생각된다.