• Ocean and Polar Research
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• v.27 no.1
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• pp.67-74
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• 2005

The phonology and reproductive effort of Zostera marina L. (Dongdae Bay and Aenggang Bay) on the southern coast of Korea were investigated from September 2002 to August 2003. The Dongdae Bay(DB) exhibited a finer sediment grain size with richer organic content than the Aenggang Bay(AB). Water temperature at DB site ranged from $7.5^{\circ}C$ in February to $25.5^{\circ}C$ in August, while water temperature at AB site ranged rrom $6.7^{\circ}C$ in February to $25.2^{\circ}C$ in september. Both populations exhibited a perennial lifB span, but the sexual reproductive effort was significantly higher at DB than AB. The reproductive shoots of DB site were developed from February to June 2003, while those of AB site from March to June 2003. At DB site, the frequency of reproductive shoot ranged from 11 to 33%, whereas reproductive shoot of AB did below 5%. Reproductive structures were larger and more abundant at DB, with the exception of number of fruits and seeds per spadix. Water temperature seems most important to regulate the timing of reproductive phase of Z. marina populations for two study sites.

• Korean Journal of Ichthyology
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• v.5 no.2
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• pp.226-234
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• 1993

Cobitis sinensis-longicorpus complex considered as hybrid origin between C. sinensis and C. longicorpus coccurred ommonly in the upper streams of the Nakdong River, Korea. Histological examinations of their gonad were accompanied with 272 individuals of C. sinensis-longicorpus complex collected. Most of fishes collected were females, however, only 6 individuals were found males. The ovarian tissues of females are completely fertile undergoing normal oogenensis. In the male gonads, testicular lobule structure with abnormal vacuolar tissues were observed. Spermatogonia and spermatocytes were also observed of their testis however spermatids or sperms were not shown in their developmental stages. From these facts, we infer that female population of C. sinensis-longicorpus complex may be unique reproductive hierarchy accomplishing their reproduction with participation of males of their closely related bisexual species.

• 대한생식의학회:학술대회논문집
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• 1997.11a
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• pp.79.1-79.1
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• 1997

• 대한생식의학회:학술대회논문집
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• 1995.12a
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• pp.73.1-73.1
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• 1995

• 대한생식의학회:학술대회논문집
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• 2002.11a
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• pp.57.2-58
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• 2002

• Development and Reproduction
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• v.6 no.1
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• pp.45-54
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• 2002

Reproductive activity of golden hamsters(Mesocricetus auratus) is regulated by the photoperiod. They are sexually active in summer and inactive in winter. Melatonin, a pineal hormone, has been known to mediate sexual activities in seasonal breeding animals. Melatonin receptor was recently identified in several animal species including hmm. But little has been known about it in relation to the reproductive activities of golden hamsters. By using reverse transcription polymerase chain reaction(RT-PCR) methods, a portion of the melatonin receptor gene(309 nucleotides) was identified in golden hamsters. The nucleotide sequence of the melatonin receptor and the amino acid sequence deduced were compared to those reported in other animals. Melatonin receptors were obviously detected in hypothalamus, pituitary containing pars tuberalis, blood, and spleen. Although the testicular weights and the levels of reproductive hormones were dramatically affected by photoperiods, the expression of melatonin receptor was not markedly changed by them. These results suggest that the action of melatonin in regulating reproduction might be mainly due to the affinity of melatonin receptor rather than the density fi melatonin receptor.

• The Journal of Korean Obstetrics and Gynecology
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• v.20 no.2
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• pp.71-82
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• 2007

목 적 : 본 연구는 기간별 구자 투약이 생쥐의 생식능력에 미치는 영향을 알아보고자 하였다. 방 법 : 이를 위해 30일, 60일, 90일 및 120일간의 구자 투약이 생쥐의 총 정자수, 활동 정자수, 정상형태 정자수, 고환조직 및 hyaluronidase activity를 측정하여, 다음과 같은 결론을 얻었다. 결 과: 1. 총 정자수는 60일과 90일 투여 후 대조군에 비하여 증가하였다. 2. 활동 정자수는 60일, 90일 및 120일 투여 후 대조군에 비하여 증가하였다. 3. 정상 형태 정자수는 60일, 90일 및 120일 투여 후 대조군에 비하여 증가하였다. 4. 고환 세정관의 조직학적 변화는 60일 투여 후에 가장 현저히 나타났다. 5. Hyaluronidase activity는 모든 투여군에서 대조군에 비하여 증가하였다. 결 론: 이상의 결과를 통해 60일 이상의 구자 투약이 남성 생식능력을 활성화 할 수 있다고 사료된다.

• Clinical and Experimental Reproductive Medicine
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• v.22 no.3
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• pp.259-265
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• 1995

• Ocean and Polar Research
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• v.27 no.2
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• pp.125-133
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• 2005

This study described the phonology and reproductive potential of four species of Korean seagrasses, Zostera caespitosa, Z. caulescem, Z. Japonica and Z. marina. Z. caespitosa and Z. caulescens sampled from a mixed stand at the subtidal area of Yulpo Bay, Geojedo of the South Sea of Korea in November 2002 and August 2003. Z japonica and Z. marina occurred at the depth between the middle intertidal and shallow subtidal (<1m below mean sea level) of Seungbongdo (in Yellow Sea) samples collected in February and October 2003. The sexual reproductive phase of the four Zostera species was apparently different in timing of flowering, reproductive period, fruiting and seed maturing. Z. caespitosa flowered from February to early May $(10-16^{\circ}C)$, and its seed production completed in early May. The reproductive shoots of Z. caulescens began to appear in January $(9^{\circ}C)$, and its flowering followed from February to June $(10-19^{\circ}C)$. The flowers of Z. japonica were observed from July to September $(18-22^{\circ}C)$, and its seeds matured from August to September. The most commonly I marina flowered from April to August $(7-21^{\circ}C)$ and developed into seeds in July. Z. caulescens, the largest plant, had the highest number of seeds per shoot and longest spadix length. Z. marina, which was intermediate In size, recorded the highest reproductive potential. The study indicates that the reproductive phase and potential of the four species of seagrass from Korea are highly related to water temperature, and the populations of these species show a perennial lifespan with a low sexual reproductive input.

• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.37-37
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• 2004