• Clinical and Experimental Reproductive Medicine
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• v.39 no.2
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• pp.68-72
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• 2012

Objective: To investigate the value of stimulated intrauterine insemination (IUI) in women with unilateral tubal occlusion. Methods: Superovulation and IUI was performed during 2003-2010 and the medical records were reviewed retrospectively. Thirty-seven infertile women (52 cycles) with unilateral tubal occlusion diagnosed by hysterosalpingography and without other causes of infertility were selected. One-hundred fourteen patients with unexplained infertility served as a control group (182 cycles). The main outcome was the clinical pregnancy rate per cycle. Results: The pregnancy rate per cycle was similar, 17.3% for the unilateral tubal occlusion group and 16.5% for the unexplained infertility group. The rate of miscarriage (11.1% vs. 23.3%) and ectopic pregnancy (11.1% vs. 6.7%) was similar between the two groups. The pregnancy rate was higher in patients with proximal occlusion (25.0%) compared with distal occlusion (13.9%) or unexplained infertility, but not statistically significant. Conclusion: Stimulated IUI can be suggested as the initial treatment option in women with unilateral proximal or distal tubal occlusion.

• Animal cells and systems
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• v.11 no.2
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• pp.227-234
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• 2007

Spermatogenesis, the reproductive cycle, and the size at first sexual maturity in male Mactra chinensis were investigated by cytological and histological observations. The spermatozoon exhibits a primitive type morphology and is similar to those of other bivalves in that it contains a short midpiece with four mitochondria surrounding the centrioles. The morphologies of the sperm nucleus type and the acrosome shape of this species are cylindrical and modified cap-like, respectively. The spermatozoon is approximately $40-45\;{\mu}m$ in length including the sperm nucleus (about $1.46\;{\mu}m$), acrosome (about $1.20\;{\mu}m$) and tail flagellum. The axoneme of the sperm tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail shows a 9+2 structure. The spawning period of this species lasts from June to September, and the main spawning occurs in July and August, when the seawater temperature is greater than $20^{\circ}C$. The percentage of individual male clams at first sexual maturity was 56.5% for those whose shell lengths were 35.1-40.0 mm, and 100% for over 45.1 mm. Accordingly, harvesting clams <35.1 mm in shell length could potentially cause a drastic reduction in recruitment, and a measure indicating a prohibitory fishing size should be taken for adequate fisheries management.

• Clinical and Experimental Reproductive Medicine
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• v.41 no.3
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• pp.140-145
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• 2014

This article reports a case of spontaneous ovarian hyperstimulation syndrome (OHSS) following a thawed embryo transfer cycle. OHSS, a potentially life-threatening condition, is an iatrogenic complication of controlled ovarian stimulation; therefore, it is very important to prevent and treat OHSS during treatment with ovulation-inducing agents. Despite our efforts to prevent OHSS, in this case, severe spontaneous OHSS occurred, which resulted in uncontrolled preterm labor and a preterm delivery and also persisted for 6 weeks after delivery. Freezing all embryos cannot entirely prevent the development of OHSS because OHSS can occur spontaneously. Although spontaneous OHSS remains a rare event, females with a history of OHSS may have an elevated risk for spontaneous OHSS. We suggest closely monitoring cases of pregnancy following thawed embryo transfer for early diagnosis of spontaneous OHSS and the use of conservative management.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.207-217
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• 1995

Various factors reducing seed yield in 4 Larix species throughout the whole reproductive cycle were investigated and partitionate losses attributed to them were determined. Pollen quality, lack of pollination, and degeneration of female gametophyte played minor roles in reducing seed yield. Failure of pollinated ovules to be fertilized was an important factor causing seed loss. Embryo degeneration was also a major factor causing seed loss in all 4 species. Strobili abortion, which causes loss of all potential seeds in a cone, was the most important factor in reducing seed loss in this study. Based on the results obtained from this studs, hybridizations in either direction between European larch and Japanese larch are likely to resulting viable seed. However, hybridization between tamarack as a mother tree and European larch are not likely to result in viable seeds being produced.

• Environmental Analysis Health and Toxicology
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• v.19 no.1
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• pp.73-80
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• 2004

숭어의 생식주기를 밝히기 위해 2002년 2월부터 2003년 3월까지 제주도 동남부 연안에서 채집하였고, 난모세포의 발달과정을 조직학적 방법으로 관찰하였다. 난모세포의 발달과정은 GSI변화와 밀접하였다. GSI는 9월에 급격히 증가하여 12월에 최고 값을 나타내었다. 난소의 조직학적 관찰결과, 염색인기와 주변인기의 난모세포는 연중 관찰되었으며,8월에는 일부에서 난황을 포함하는 난모세포가 관찰되었다. 대부분의 난모세포가 10월과 12월에는 난황구기 단계의 난모세포로 발달했다. 10월과 12월에 난황구기 난모세포들을 가진 개체의 출현이 가장 높았으며, 잔존여포와 퇴화 난모세포는 2월부터 관찰되었다. 숭어의 주 산란기는 11월에서 1월이고, 난군동기발달형의 난소를 가지며 외양으로 이동하여 산란하는 어류에 속한다.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2001.02a
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• pp.46-49
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• 2001

R. Philippinarum is dioecious and oviparous. In the early vitellogenic oocyte, the Golgi apparatus and mitochondria present in the perinuclear region are involved in the formation of lipid droplets and in lipid granule formation. In the late vitellogenic oocyte, the endoplasmic reticulum, mitochondria in the cytoplasm are involved in the formation of proteid yolk granules. At this time, exogenous lipid granular substance and glycogen particles in the germinal epithelium are passed into the ooplasm of oocyte through the microvilli of the vitelline envelope. Ripe oocytes are about 55-60 $\mu$ m in diameter. The spawning period was once a year between early June and early October, and the main spawning occurred between July and August when seawater temperature was approximately 20 C. The reproductive cycle of this species can be categorized into five successive stages: early active stage (February to March), late active stage (April to May), ripe stage (April to August), partially spawned stage (June to October), and spent/inactive stage (August to March). Gonad developmental phases by histological qualitative analysis showed similar results with those of quantitative image analysis.

• Development and Reproduction
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• v.24 no.2
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• pp.79-88
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• 2020

This study was carried out to obtain information on the developmental biology and the management of biological resources of the abalone Haliotis gigantea in Korea. The sex ratio (female:male) in the present study was 1:1.7 and the proportion of females was 36.6% (n=106/290). Their gonadal structures displayed definitive seasonal changes which were similar in pattern to the changes in the gonad index (GI). The GI showed a pattern of definitive seasonal changes in both males and females it was high in the fall and low in the spring. The reproductive cycle could be categorized into the following six stages: inactive, early active, late active, ripe, spent, and degenerative stage. Based on the monthly changes in GI and stages of gonadal development, October to November was determined to be the main spawning period for H. gigantea on Jeju Island, Korea.

• The Korean Journal of Zoology
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• v.38 no.1
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• pp.96-105
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• 1995

본 연구는 옴개구리(Rana rugosa)의 생식주기를 파악하고 이들 난자들의 체외 성숙조건을 구하기 위하여 수행하였다 개구리들의 gonadosomatic index(G51)는 4월에서 8월사이에는 비교적 낮았고 9월에서 이듬해 3월까지는 높았다 여포들의 성장은 주로 6월에서 9월 사이에 이루어지는데 난소내에서도 여포들의 성장 속도는 일부 다른 것으로 나타났다. 야외 관찰에서 이 개구리들은 서식지의 온도에 따라 4월에서 7월 사이에 산란을 한다는 것과 10월에서 이듬해 3월까지 동면을 한다는 것을 말았다. 산란기에 취한 여포 난자들은 생체외 배양에서 progesterone에 성숙반응(germinal vesicle breakdown(GVBD))을 일으키지 않았다. 그러나 protein klnase C(PKC)의 촉진제인 12-O-tetradecanoylphorbol 13-acetate(TPA) 혹은 Na+/K+ ATPase의 저해제인 ouabain을 progesterone과 동시에 처리했을 때에는 성숙반응을 일으켰다(각각 86%와 80%). TPA 로 핵붕괴를 일으킨 난자의 세포질을 미성숙 난자에 주입하면 미성숙 난자의 핵붕괴를 유도하였으며 성숙된 다른 종의 난자들의 세포질도 이와 같은 효과를 나타내었다. TPA의 성숙유도 효과는 5분의 노출 기간으로도 충분하였으며 PKC의 저해제인 H-7을 처리하면 그 효과가 없어졌다 이러한 결과들은 옴개구리의 난자는 호르몬에 성숙반응을 일으킨지 않으나 PKC 활성화 이후 단계는 정상이라는 것을 의미한다.

• Development and Reproduction
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• v.25 no.4
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• pp.299-303
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• 2021

The ascidian Halocynthia aurantium (sea peach), a marine invertebrate, belongs to the same genus of the phylum Chordata along with the ascidian Halocynthia roretzi (sea pineapple), which is one of the model animals in the field of developmental biology. The characteristics of development and reproduction of H. aurantium are not yet known in detail. In order to find out the spawning period of H. aurantium, we investigated development of the gonads during the annual reproductive cycle. Testis and ovary were both in the bisexual gonads (ovotestes) of H. aurantium, which is a hermaphrodite like H. roretzi. In H. aurantium, the right gonad was longer and slightly larger than the left gonad throughout the year. In each gonad, the number of the testis gonoducts was slightly higher than that of the ovary gonoducts. These features were similarly observed in H. roretzi. However, the number of the testis gonoducts and the ovary gonoducts in each gonad of H. aurantium was about half that of H. roretzi. The gonads of H. aurantium contracted during the winter and summer seasons. The gonads decreased to the smallest size around February, and then started to increase again in March. The gonads were most developed in September of the year. Therefore, it is estimated that the spawning of H. aurantium begins around this period.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.3
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• pp.217-226
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• 2012

Reproductive ecology of the sharp toothed eel, Muraenesox cinereus was investigated based on the samples captured in southern Korean waters from January 2010 to December 2011. Gonadosomatic index began to increase in April, and reached maximum between July to August. After spawning it began to decrease from October. Reproductive season was estimated to April-September, with peak in July. Fecundity was proportional to the size of the female, with the clutch size varying from 56,000 eggs in the smallest female (anal length, 27.0cm) to 1,400,000 eggs in the largest (anal length, 49.5cm). Size at 50% sexual maturity ($AL_{50}$), determined from mature females, were 21.9cm. Annual reproductive cycles of this species could be divided into four successive stages; immature stage (October-February), maturing stage (March-May), mature stage (June-August) and spent stage (August-October).