• Fisheries and Aquatic Sciences
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• 제25권1호
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• pp.12-19
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• 2022

In the present study, we investigated the effects of recombinant eel gonadotropins (rec-GTHs) on maturation induction in immature ovarian culture in vitro and sex steroid hormones in vivo in the Japanese eel Anguilla japonica. To study the in vitro effects of rec-GTHs on estradiol-17β (E2) production in immature ovarian tissues, ovarian tissues were incubated with different doses of rec-follicle-stimulating hormone (rec-FSH) or rec-luteinizing hormone (rec-LH). The results revealed that the E2 levels in the rec-FSH (0.1, 0.5, or 1 ㎍/mL)- and rec-LH (0.1 or 0.5 ㎍/mL)-treated groups were significantly higher than those in the female eels from the control group. Furthermore, to investigate the in vivo effects of rec-GTHs on the gonadosomatic index (GSI) and plasma sex steroid hormone levels, the eels were injected intraperitoneally with eel's ringer (control), salmon pituitary extract (SPE; for female eels), human chorionic gonadotropin (hCG; for male eels), rec-FSH, rec-LH, and rec-FSH + rec-LH once a week. The results revealed that except for the SPE and the hCG groups, none of the groups exhibited a significant difference in GSI values. However, in vivo plasma E2 levels increased at the end of 4 weeks after rec-FSH treatment in female eels. Based on these results, it is suggested that rec-GTHs may have a positive effect on sexual maturation in female eels; however, further studies on complementary rec-protein production systems and additional glycosylation of rec-hormones are needed to elucidate hormone bioactivity in vivo and in vitro.

• Fisheries and Aquatic Sciences
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• 제4권4호
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• pp.208-218
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• 2001

We have investigated the gonad index (GI), gonadal development, reproductive cycle, first sexual maturity, sex ratio, the number of spawned eggs and spawning frequency of the Manila clam, Ruditapes philippinarum. Samples were collected from the intertidal zone of Komso Bay, Korea from January to December in 1999. Monthly changes in the gonad index (GI) and condition index showed a similar pattern in the reproductive cycle. The spawning period was once a year between early June and early October, there was a spawning peak between July and August when seawater temperature was over $20^{\circ}C$. The reproductive cycle of this species can be categorized into five successive stages; early active (February to March), late active (April to May), ripe (April to August), partially spawned (June to October), and spent/inactive stage (August to March). Percentages of first sexual maturity of female and male clams of l5.1-20.0mm in shell length were $56.3\%$ and $60.0\%$, respectively, and $100\%$ for the clams >25. mm. The sex ratio of individuals >15.1 mm in shell length was about 1:1 $(\chi^2= 0.02,\;p>0.05)$. Number of the eggs released from each clam by the induction increased as the size of clam in terms of shell length increased. Mean number of the eggs from the second induction of the spawning was $75.35-84.30\%$ $(average\;79.81\%)$ of the number of the eggs released in the first spawning. Our data indicated that R. philippinarum in Komso Bay has one major spawning peak with over two minor spawning, and the interval of each spawning was estimated to be approximately 15-17 (average 16.5) days.

• 수산해양교육연구
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• 제24권6호
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• pp.1003-1012
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• 2012

The gonadosomatic index (GSI), sex steroid hormones and gonadal development of roughscale sole Clidoderma asperrimum cultured in indoor tank were investigated to evaluate its sexual maturation and reproductive cycle. The highest GSI values of female and male were $6.91{\pm}4.03$ (May) and $0.16{\pm}0.08$ (August), respectively. The reproductive cycle would be classified into four successive developmental stages: growing stage (December to February), maturation stage (March to April), ripe and spawning stage (May to June), recovery and resting stage (July to November). The highest plasma testosterone (T) and estradiol-$17{\beta}$ ($E_2$) levels of female were $259.4{\pm}76.8$ and $633.3{\pm}182.5$ pg/mL, respectively in May. Also $17{\alpha}$, $20{\beta}$-dihydroxy-4-pregen-3-one ($17{\alpha}$, $20{\beta}$-OHP) levels of female peaked in April before spawning season ($244.2{\pm}42.5$ pg/mL). The highest plasma testosterone (T) and 11-ketotestosterone levels of male were $231.0{\pm}46.0$ and $273.9{\pm}54.5$ pg/mL, respectively in April. But there was no significant difference in $17{\alpha}$, $20{\beta}$-OHP.

• 정신신체의학
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• 제6권2호
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• pp.97-103
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• 1998

A dolescence can be defined as the period between pubescence and physical maturity, and the passage through adolescence(age of 12-19) forms a critical period. Major developmental tasks of adolescence are construction of an emancipated identity, realistic ambitions, and reasonable ideals, and the further development of sexual and social identities. In early adolescence one struggles to adjust psychologically to the spurt in growth and tensions filled with sexual and aggressive impulses. There are reshuffling of peer groups due to differing rates of maturation, early adolescence crushes, sublimation of sexuality, and the resurgence of oedipal feelings. One reaches so-called period of formal operations in cognitive development. In mid-adolescence one struggles to overcome family attachments and controls, and it is a time marked by revolt and conformity. One has to overcome sexual repression while caught in reactivation of oedipal attachment. Peer groups gains in importance, and the peer group changes into a youth group that carries the youth culture. Late adolescence is a period of achieving an ego identity and capacities for intimacy. One has to prevent premature closure : Identity foreclosure limits both opportunity and the ability to guide one's own life. Gradually adolescent begins to have a loss self-centered and narcissistic orientation to one's sexual and affectional needs, and becomes involved in love relationship.

• 환경생물
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• 제33권2호
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• pp.248-255
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• 2015

본 연구는 다시마 유리배우체의 분리, 재생 및 성숙 유도 조건을 구명하기 위하여, 4개의 온도 조건 (5, 10, 15, $20^{\circ}C$), 4개의 조도조건 (5, 10, 20, $40{\mu}mol\;m^{-2}\;s^{-1}$) 및 3개의 광주기 조건 (14 : 10, 12 : 12, 10 : 14 h L : D)에서 배양을 실시하였다. 다시마 암배우체의 생장은 $15^{\circ}C$, $20{\mu}mol\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D)에서 촉진되었으며, 수배우체의 생장은 $15^{\circ}C$, $5{\mu}mol\;m^{-2}\;s^{-1}$, 14 : 10 h (L : D)에서 촉진되었다. 암배우체의 성 성숙은 $5^{\circ}C$, $20{\sim}40{\mu}mol\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D)에서 촉진되었으며, 수배우체의 성 성숙은 $15^{\circ}C$, $40{\mu}mol\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D)에서 촉진되었다. 이러한 다시마 암수유리배우체의 재생 및 성숙 유도 조건은 다시마의 품종개발과 교잡육종을 위한 유리배우체 배양에 가장 기본적인 자료로 활용될 것이다.

• 환경생물
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• 제35권4호
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• pp.622-630
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• 2017

본 연구에서는 다양한 온도(5, 10, 15 and $20^{\circ}C$), 조도(5, 10, 20 and $40{\mu}mol\;photons\;m^{-2}\;s^{-1}$) 및 광주기(14 : 10, 12 : 12 and 10 : 14 h L : D) 조건에서 미역 배우체의 분리, 재생 및 성숙 조건을 파악하였다. 암배우체 단편은 $15^{\circ}C$, $20{\mu}mol\;photons\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D) 조건에서 빠른 생장을 보인 반면 수배우체는 $15^{\circ}C$, $5{\mu}mol\;photons\;m^{-2}\;s^{-1}$, 14 : 10 h (L:D) 조건에서 빠른 생장을 보여 차이를 나타냈다. 암수배우체의 최적 성숙 조건은 각각 $5^{\circ}C$, $20{\sim}40{\mu}mol\;photons\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D) 조건과 $15^{\circ}C$, $40{\mu}mol\;photons\;m^{-2}\;s^{-1}$, 10 : 14 h (L: D) 조건이었다. 본 연구 결과 확인된 미역 유리배우체의 재생과 성숙 조건은 미역의 형질개선과 교잡 육종 등을 위한 기초자료로 활용될 수 있다.

• 환경생물
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• 제36권4호
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• pp.576-583
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• 2018

본 연구에서는 다양한 온도(5, 10, 15, 20, $25^{\circ}C$), 조도(10, 20, 40, 60, $80{\mu}mol\;photons\;m^{-2}\;s^{-1}$) 및 광주기(10:14, 12:12, 14:10 h L:D) 조건에서 개다시마 유리배우체 단편의 생장 및 성숙 유도조건을 파악하였다. 암배우체 단편의 생장은 $20^{\circ}C$, $20{\mu}mol\;photons\;m^{-2}\;s^{-1}$, 10:14 h (L:D) 조건에서 빠른 생장을 보인 반면 수배우체는 $15^{\circ}C$, $20{\mu}mol\;photons\;m^{-2}\;s^{-1}$, 14:10 h (L:D) 조건에서 빠른 생장을 보여 차이를 나타내었다. 암배우체의 최적 성숙조건은 $15^{\circ}C$, $40{\mu}mol\;photons\;m^{-2}\;s^{-1}$, 14:10 h (L:D) 조건에서 가장 빠른 성숙을 보인 반면 수배우체는 $10^{\circ}C$, $20{\mu}mol\;photons\;m^{-2}\;s^{-1}$, 10:14 h (L:D) 조건에서 빠른 성숙을 보여 차이를 나타내었다. 본 연구 결과 확인된 개다시마 유리배우체 단편의 생장 및 성숙조건은 개다시마의 자원조성 및 대량양식 기반조성의 기초자료로 활용될 수 있다.

• The Plant Pathology Journal
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• 제30권3호
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• pp.236-244
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• 2014

The plant pathogen Fusarium graminearum causes Fusarium head blight in cereal crops and produces mycotoxins that are harmful to animals and humans. For the initiation and spread of disease, asexual and sexual reproduction is required. Therefore, studies on fungal reproduction contribute to the development of new methods to control and maintain the fungal population. Screening a previously generated transcription factor mutant collection, we identified one putative $C_2H_2$ zincfinger transcription factor, pcs1, which is required for both sexual and asexual reproduction. Deleting pcs1 in F. graminearum resulted in a dramatic reduction in conidial production and a complete loss of sexual reproduction. The pathways and gene ontology of pcs1-dependent genes from microarray experiments showed that several G-protein related pathways, oxidase activity, ribosome biogenesis, and RNA binding and processing were highly enriched, suggesting that pcs1 is involved in several different biological processes. Further, overexpression of pcs1 increased conidial production and resulted in earlier maturation of ascospores compared to the wild-type strain. Additionally, the vegetative growth of the overexpression mutants was decreased in nutrient-rich conditions but was not different from the wild-type strain in nutrient-poor conditions. Overall, we discovered that the pcs1 transcription factor positively regulates both conidiation and sexual reproduction and confers nutrient condition-dependent vegetative growth.

• Mycobiology
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• 제49권3호
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• pp.258-266
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• 2021

The velvet regulators VosA and VelB are primarily involved in spore maturation and dormancy. Previous studies found that the VosA-VelB hetero-complex coordinates certain target genes that are related to fungal differentiation and conidial maturation in Aspergillus nidulans. Here, we characterized the VosA/VelB-inhibited developmental gene vidD in A. nidulans. Phenotypic analyses demonstrated that the vidD deleted mutant exhibited defect fungal growth, a reduced number of conidia, and delayed formation of sexual fruiting bodies. The deletion of vidD decreased the amount of conidial trehalose, increased the sensitivity against heat stress, and reduced the conidial viability. Moreover, the absence of vidD resulted in increased production of sterigmatocystin. Together, these results show that VidD is required for proper fungal growth, development, and sterigmatocystin production in A. nidulans.

• 환경생물
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• 제27권4호
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• pp.369-374
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• 2009

멸종위기에 처한 꼬치동자개(Pseudobagrus brevicorpus)의 보전과 복원을 위한 기초 자료를 제공하기 위하여 인공사육 환경에서 사육된 종묘에서 친어까지의 성장과 성성숙 특징들을 조사하였다. 부화 후 698일의 인공사육 기간 동안 전장과 체중은 각각 $89.22{\pm}10.29mm$와 $70.93{\pm}7.68g$로 성장하였고, 전장 (TL)과 체중(BW)의 관계는 $BW=5{\times}10^{-5}\;TL^{2.678}$ ($R^2=0.995$)로 나타났으며, 생존율은 74.2%였다. 암컷과 수컷의 성비는 1 (암컷, 471) : 1 (수컷, 473)이었다. 부화 후 663일째에 암컷의 전장과 체중은 각각 $78.38{\pm}0.92\;mm$과 $6.38{\pm}0.20\;g$로 나타나 수컷의 $87.44{\pm}1.07mm$와 $8.43{\pm}0.31g$에 비해 높았으나, 비만도는 암컷이 수컷에 비해 유의적으로 값을 보였다(P<0.05). 암컷 1마리당 포란수는 평균 734개(508~867개)였고, 난경은 0.04~1.65mm의 범위를 보였다. 인공 사육된 친어는 만 2년이 되던 6월 초순에 인간 융모성 고나도트로핀(human chorionic gonadotropin: HCG)을 주사한 후 1~2일 사이에 산란이 가능하였고, 부화된 개체는 평균 216마리(113~338마리)였다.