• 한국수산과학회지
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• 제47권5호
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• pp.567-576
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• 2014

This study investigated the physiological effects of a diet containing calcium oxide (CaO) on the olive flounder, Paralichthys olivaceus. The results indicate that the amount of calcium in the blood was higher in the calcium group compared with the controls. The aspartate amino transferase (AST) and alanine amino transferase (ALT) levels were lower in the calcium group, while lysozyme activity was higher in the calcium group. Histologically, fish in the calcium group had more hepatocytes in the liver and more intact scales. In addition, an attack experiment using Vibrio anguillarum (KCTC-2711) and Edwardsiella tarda (KCTC-3657) showed that the survival was higher in the calcium group compared with the controls. These results suggest that feeding fish CaO when they require it, such as during periods of gonadal maturation and rapid growth, will increase their immunity and resistance to pathogens.

• Clinical and Experimental Reproductive Medicine
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• 제18권2호
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• pp.189-196
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• 1991

Long-term administration of luteinizing hormone-releasing hormone(LHRH) agonists, through a process of pituitary desensitization and down-regulation of receptors, inhibits the secretion of gonadotropin and sex-steroids and induces a reversible suppression of gonadal activity. This approach can be used as an effective endocrine therapy for some hormone-dependent tumors. We have used D-Trp6-LHRH, a long acting LHRH agonist, for the treatment of eleven patients with uterine leiomyomas, thereafter myomectomy was performed in seven cases and observed the ultrastructural changes of leiomyoma with an electron microscope. The use of LHRH agonist may be effective in reducing the size of a myoma considerably by primarily inducing medical hypophysectomy and would allow easier surgical removal. Electron microscopic findings of myoma cells after the use of LHRH agonist included the following: loss of cristae and swelling nuclear chromatin, perinuclear vacuolation in cytoplasm. Bone mineral density was slightly decreased, however, the difference was not statistically significant.

• 한국양식학회지
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• 제8권3호
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• pp.231-240
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• 1995

유도된 3배체 미꾸라지 Misgurnus mizolepis의 자, 치어를 재료로 시원생식세포의 출현, 생식 융기 및 원시생식소 형성 및 발달 과정을 조사하여 2배체와 비교하였다. 2배체와 3배체 모두 시원생식세포는 부화후 2일, 체후부의 중신관과 장관사이의 섬유성 간충직을 따라 식별되었다. 생식 융기는 부화후 4-5일 체벽 상피로부터 복강으로 돌출되기 시작하였고 원시 생식소는 부화후 8일의 후기자어에서 식별되어, 부화후 20-25일까지 시원생식세포들의 분열 증식과 풍부한 섬유성 결체조직의 형성과 함께 앞쪽으로 신장되어 가는 선상의 생식소로 나타나 두 실험군 모두 동일한 조직학적 특성을 보였다. 시원생식세포의 형태는 2배체와 3배체 모두 원반형에서 타원형 내지 구형으로 발달되었고 크기의 차는 없었으나, 원시생식소의 길이는 2배체가 3배체에 비해 길게 나타났다.

• Clinical and Experimental Reproductive Medicine
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• 제39권3호
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• pp.95-106
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• 2012

It has been revealed that multiple cohorts of tertiary follicles develop during some animal estrous cycle and the human menstrual cycle. To reach developmental competence, oocytes need the support of somatic cells. During embryogenesis, the primordial germ cells appear, travel to the gonadal rudiments, and form follicles. The female germ cells develop within the somatic cells of the ovary, granulosa cells, and theca cells. How the oocyte and follicle cells support each other has been seriously studied. The latest technologies in genes and proteins and genetic engineering have allowed us to collect a great deal of information about folliculogenesis. For example, a few web pages (http://www.ncbi.nlm. nih.gov; http://mrg.genetics.washington.edu) provide access to databases of genomes, sequences of transcriptomes, and various tools for analyzing and discovering genes important in ovarian development. Formation of the antrum (tertiary follicle) is the final phase of folliculogenesis and the transition from intraovarian to extraovian regulation. This final step coordinates with the hypothalamic-pituitary-ovarian axis. On the other hand, currently, follicle physiology is under intense investigation, as little is known about how to overcome women's ovarian problems or how to develop competent oocytes from in vitro follicle culture or transplantation. In this review, some of the known roles of hormones and some of the genes involved in tertiary follicle growth and the general characteristics of tertiary follicles are summarized. In addition, in vitro culture of tertiary follicles is also discussed as a study model and an assisted reproductive technology model.

• 한국패류학회지
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• 제4권1호
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• pp.30-41
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• 1988

The gonadal development, the annual reproductive cycle and the first sexual maturity of surf clam, Mactra veneriformis Reeve were studied histologically. Speciemens were monthly collected at the intertidal zone of Naechodo, Chollabuk-do, Korea, for one year from March 1986 to February 1987. Sexuality of the clam is dioecious. The gonads were located between the subregion of mid-intestinal gland in the visceral cavity and the reticular connetive tissues of the foot, The ovary is composed of a number of ovarian sacs, and the testis comprise several testiculat lobules. The undifferentiated mesenchymal tissues and eosinophilic granular cells function as nutritive cells in the early stage. The ripe eggs were about 50-60${\mu}{\textrm}{m}$ in diameter, and they were wurroundedby the gelatinous membranes. The spawing period was from early June to September the main spawning occurred beetween July and August when the water temperature reached above 24$^{\circ}C$. The annual reproductive cycle of this species could be classified into five successive stages: multiplicative(January to March), growing(March to May), mature(April to August), spent(June to September), degenerative and resting(September to February). The monthly changes of fatness coefficient closely correlated with the annual reproductive cycle. Percentages of the first sexual maturity of female and male clams were over 50% among those individals ranging from 2.1 To 2.5cm, and 100% in those over 2.6cm in shell length.

• 환경생물
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• 제22권1호
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• pp.159-166
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• 2004

본 연구는 PCBs가 칼납자루의 생식에 미치는 영향을 조직학적인 방법을 사용하여 조사하였다. 0, 3.4, 9.3 그리고 25.8 ${\mu}g\; L^{-1}$의 PCBs에 8주 동안 노출 실험한 결과, PCBs에 의한 행동과 생존율에는 영향을 미치지 않았다. 대조구와 비교해볼 때 PCBs에 노출된 어류들은 생식소발달, 생식소중량지수 (GSI), 간중량지수 (HSI), 혼인색지수(NCI) 및 산란관지수(OLI)의 차이를 보였다. 이러한 결과는 PCBs가 이들 어류의 정상적인 생식소 발달 과정을 방해하는 것을 보여준다.

• The Korean Journal of Ecology
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• 제2권1호
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• pp.9-14
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• 1978

The study was made to expand the knowledge of the ecology of Cobitis koreensis which is very common in the upper and middle part of rivers in western part of Korea. A number of C. koreensis are found in the creek of Jeonju-cheon located at Segjang-ri, Wanju-gun, Jeonrabug-do Province. The area studied has pebble bottoms. The flow velocity of the river ranges from 20cm to 40cm per second under normal conditions. The sex ratio of male to female was 1:1.34 and the female was 10~25mm larger than the male in total length. Length-frequencies in this population indicate that 20~40 mm fish group is underyearling, 40~60mm is a yearling, and 60~85mm is two-year-old. And the fish longer than 90mm in total length is regarded as being over three-year-old. Based on the ratio of gonadal weight to body weight, spawning in this species began in April and expanded well into June with water temperature 20~26。C, and the individuals became sexually mature over the two-year-old. The number of the eggs was counted from ten matured female fishes. The mean number of eggs in seven 72.6~81.4mm fishes was 908 (595-1, 229) and that of the rest three 86.0~89.0mm was 1, 674 (1, 337-2, 023). The contents of stomach in the other fifteen specimens captured in September 1977 were investigated. While the younger fed almost on the algae, the foods in the adult were largely aquatic insects.

• Fisheries and Aquatic Sciences
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• 제3권2호
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• pp.135-142
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• 2000

In order to clarify the role of gonadal sex steroids in the synthesis of gonadotropin (GTH) subunits in immature rainbow trout, we examined in vitro and in vivo effects of testosterone (T) on the pituitary mRNA levels of GTH I $\beta$, GTH II$\beta$ and a subunits by Northern blot analysis and on the pituitary content levels of GTH I$\beta$ and GTH II$\beta$by radioimmunoassay (RIA). The mRNA levels of the a subunit in T-treated fish were not changed more dramatically than those in control fish both in vivo and in vitro. Interestingly, the mRNA levels of GTH I$\beta$ in T-treated fish were shown to be slightly lower than those in the control fish under these experimental conditions, but no differences were observed in pituitary GTH I$\beta$ contents. In contrast, the mRNA levels and pituitary contents of GTH II$\beta$ subunit were strongly increased by T both in vivo and in vitro. These results demonstrate that the expressions of GTH I$\beta$ and II$\beta$ subunit genes in immatue rainbow trout pituitary are subjected to differential regulation by T.

• 대한의생명과학회지
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• 제7권3호
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• pp.103-110
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• 2001

$\alpha$-Fetoprotein(AFP) is a good marker for the detection of several diseases such as hepatocellular carcinoma, gonadal germ cell tumor, gastric tumor, and Down's syndrome. In this study, we developed ELISA, using synthetic peptides corresponding to the epitopes of AFP. Five kinds of peptides were synthesized from AFP to produce antibodies in rats that recognize AFP in human plasma as well as amniotic fluid and do not cross-react with serum albumin. All five kinds of antibodies showed good reactivities with their peptide-keyhole limpet hemocyanin conjugates. Anti-synthetic peptide 1 (R-N-E-Y-G-I-A-S-I-L, 4-13) antibody, in particular, reacted well with AEP as well as synthetic peptide 1-KLH but not with human serum albumin. The binding affinity(Kd) was 2.7$\times$10$^{-9}$M for peptide 1 and 6.8$\times$10$^{-8}$M for AEP. The range for measurement of AFP was 10~1,000 ng/ml. The within-assay and between-assay coefficients of variance(CV) were 4.83% and 10.97%, respectively. In a sample of 31 sera and 33 amniotic fluids, there was a good correlation between AFP values determined in this assay and those in a commercial kit. These results indicate that the antibodies against synthetic peptides corresponding to the epitopes of AFP are highly specific to APP and synthetic peptide-based ELISA would be useful for the measurement of human AFP.

• 한국발생생물학회지:발생과생식
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• 제20권4호
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• pp.367-377
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• 2016

Red spotted grouper, Epinephelus akaara, is a popular aquaculture species and a protogynous hermaphrodite. Induction of artificial sex change at the time of primary sex differentiation is of interest but has not been successful due to the lack of necessary basic information. To find out the potential neuroendocrine influence on the primary sex differentiation, the expression of key genes in the brain was investigated during the formation of ovarian cavity. Expression of cyp19a1b, esr1, gnrhr1, fsh, lh and cga in the brain was positively associated with the formation of ovarian cavity, showing gradual increase as the formation proceeds. However, the expression of gnrh1 was suppressed during the early part of the ovarian cavity formation, signifying potential hypothalamic influence on the primary sex differentiation in this species.