• 한국패류학회지
• /
• 제4권1호
• /
• pp.30-41
• /
• 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.

• Animal cells and systems
• /
• 제3권4호
• /
• pp.375-383
• /
• 1999

Gonadal development, gametogenesis, reproductive cycle, and first sexual maturity of Reishia clavigera were investigated monthly from July 1998 to June 1999 through cytological and histological observations. R. clavigera had separate sexes, and was an internal fertilizer. The ma1e penis was located near the two tentacles. The ovary and testis were composed of a great number of oogenic lobules and spermatogenic tubules, respectively. The size of ripe oocyte ranged from 130 to 140 ${\mu}$m in diameter. The peripheral cytoplasm of the germinal vesicle of the ripe oocyte in many cases were surrounded by smaller yolk granules, while the eccentric cytoplasm was occupied with larger ones. The reproductive cycle of R. clavigera could be classified into five successive stages: early active, late active, ripe, spawning, and recovery. Spawning of females occurred from early July to August when the seawater reached above 24.8$^{\circ}C$. Spawning of males occurred from early June to August in the water above 22.8$^{\circ}C$. Minimum size for sexual maturity of both sexes was above 10.0 mm in shell height. Each egg capsule was a cylinder or spindle in shape, 4-6 mm in length and 1-2 mm in width. Colors of newly spawned egg capsules showed yellowish white or pale yellow, while those with veliger larvae showed pale black, and released larvae or dead egg capsules showed black violet. The fecundity in an egg capsule ranged from 70 to 91 eggs (mean＝80.28 eggs).

• Animal cells and systems
• /
• 제8권1호
• /
• pp.33-40
• /
• 2004

Reproductive cycle and spawning rhythm with lunar cycle of the ascidian, Halocynthia hilgendorfi ritteri were investigated by histological examination. The specimens were sampled in the coastal waters of Yongdam, northwest of Jeju Island, Korea, from November 2001 to January 2003. H. hilgendorfi ritteri is a synchronous hermaphrodite; the gonads are located in the mantle. The reproductive cycle can be grouped into the following successive stages in the ovary: growth (February to June), vitellogenesis (April to September), mature (July to December), spent (November to February), and recovery (December to April). Likewise, in the testis, the stages observed were: growth (October), mature (October to December), spent (November to February), and resting (January to September). Major spawning probably occurs between November and January, when water temperatures decrease. The histological observations of the gonads suggested that this species is a multiple spawner during the spawning period. Spawning occurred between the new moon and full moon, and again between the full moon and new moon, suggesting that the spawning rhythm is influenced by the lunar cycle.

• Clinical and Experimental Reproductive Medicine
• /
• 제26권2호
• /
• pp.157-161
• /
• 1999

Recent studies clearly demonstrated that the novel expression of LH gene in the rat testis, and suggested the local action of the LH-like molecule. The present study was performed to analyze the expression of LH genes in the rat accessory reproductive organs. Expression of LH subunit genes in the rat uterus and epididymis was demonstrated by reverse transcription-polymerase chain reaction (RT-PCR) and specific LH radioimmunoassay (RIA). The $LH_{beta}$ transcripts in these organs contained the published cDNA structure, the pituitary type exons 1-3, which encoded the entire $LH_{beta}$ polypeptide. Presence of the transcripts for the ${\alpha}$-subunit in the rat reproductive tissues were also confirmed by RT-PCR. In the LH RIA, significant levels of LH were detected in crude extracts from the rat ovary, uterus and epididymis. The competition curves with increasing amount of tissue extracts were parallel with those of standard peptide, indicating that the immunoreactive LH-like materials in these tissues are similar to authentic pituitary LH molecule. In rat epididymis, the highest amount of immunoreactive LH was detected in corpus area. Our findings demonstrated that the genes for LH subunits are expressed in the rat accessory reproductive organs, and suggested that these extrapituitary LH may act as a local regulator with auto and/or paracrine manner.

• BMB Reports
• /
• 제49권9호
• /
• pp.488-496
• /
• 2016

Estrogens are the key hormones regulating the development and function of reproductive organs in all vertebrates. Recent evidence indicates that estrogens play important roles in the immune system, cancer development, and other critical biological processes related to human well-being. Obviously, the gonads (ovary and testis) are the primary sites of estrogen synthesis, but estrogens synthesized in extra- gonadal sites play an equally important role in controlling biological activities. Understanding non-gonadal sites of estrogen synthesis and function is crucial and will lead to therapeutic interventions targeting estrogen signaling in disease prevention and treatment. Developing a rationale targeting strategy remains challenging because knowledge of extra-gonadal biosynthesis of estrogens, and the mechanism by which estrogen activity is exerted, is very limited. In this review, we will summarize recent discoveries of extra-gonadal sites of estrogen biosynthesis and their local functions and discuss the significance of the most recent novel discovery of intestinal estrogen biosynthesis.

• 대한수의학회지
• /
• 제39권4호
• /
• pp.760-764
• /
• 1999

A totoal of 219 pigs, 109 necropsy-pigs at the diagnostic laboratory of Cheju National University and 110 slaughter-pigs in Cheju, were evaluated for the prevalence of tissue antigen and serum antibody for spontaneus porcine reproductive and respiratory syndrome(PRRS). Tissues from 219 pigs examined for PRRS viral antigen by immmunohistochemistry included lung(cranio-ventral lobes and dorso-caudal lobes), tonsil, tracheobronchial lymph node, mesenteric lymph node, heart, kidney, liver, spleen, testis, ovary, brain, and spinal cord. Sera from 180 pigs were tested for the presence of antibody to PRRS virus by the indirect fluorescent antibody assay (IFA). In the examination of serum antibody and tissue antigen for PRRS virus, serum antibody titers were considered as positive in 10%(18/180) of animals tested and PRRS viral antigen was detected in tissues of 4%(9/219) of the pigs. PRRS virus tissue antigen was most commonly detected by immunohistochemistry in the cranio-ventral lobe and tonsil. We also confirmed the distribution of tissue antigen and prevalence of serum antibody to PRRS virus in Cheju. The detection of viral antigen by immunohistochemistry in tonsils and cranio-ventral lobes proved to be a very useful method for PRRS diagnosis.

• 한국식품위생안전성학회지
• /
• 제12권3호
• /
• pp.234-239
• /
• 1997

Guh Sung Y.L.S.-95 is one of the polyacidic solution of which main component is acetic acid. We investigated the subchronic toxicity of the Guh Sung Y.L.S.-95 using SPF ICR mouse for 4 weeks. The Guh Sung Y.L.S.-95 was administered by gastric intubation, 1.0, 2.5, 5.0 g/kg body weight. The results are as follows: 1. There are no adverse effects on the clinical obserbation and body weight changes. Also, there are some significant changes in organ weight, but it was meaningless because of the absence of dose-response relationships. 2. In the hematological patterns of administered mouse, there are no significant changes between the treated groups. Also, there are no serological enzymatic changes in the treated mouse. In the 1.0 g/kg treated group, ASP activity was increased significnatly compared with control group. But, this level of activity was fall under the normal physiological range of control mouse. 3. Histopathological findings of the brain, liver, heart, spleen, kidneys, stomach, lung, testis, ovary, uterus and thymus were not observed in the treated mouse. From the above results, the Guh Sung Y.L.S.-95 has no toxicity upto the 5.0 g/kg/day of oral dose for 4 weeks.

• 대한방사선기술학회지:방사선기술과학
• /
• 제43권3호
• /
• pp.169-176
• /
• 2020

Interventional radiology is performed under real-time fluoroscopy, and patients are exposed to a wide range of exposures for a long period of time depending on the examination and procedure. However, studies on radiation protection for patients during an intervention are insufficient. This study aims to evaluate the doses exposed during the intervention and the applicability of 3D printing materials. The organ dose for each intervention site was evaluated using a monte carlo simulatio. Also, the dose reduction effect of the critical organs was calculated when using a shielding device using 3D printing materials. As a result, the organ dose distribution for each intervention site showed a lower dose distribution for organs located far from the x-ray tube. It was analyzed that the influence of scattered rays was higher in the superficial organs of the back of the human body where x-rays were incident. The dose reduction effect on the critical organ using the 3D printing shield showed the highest testis among the gonads, and in the case of other organs, the dose reduction effect gradually decreased in the order of the eye, thyroid, breast, and ovary. Accordingly, it is judged that the 3D printed shield will be sufficiently usable as a shielding device for the radiation protection of critical organs.

• 한국발생생물학회지:발생과생식
• /
• 제22권1호
• /
• pp.1-8
• /
• 2018

The annual reproductive cycle of the Korean endemic slender catfish, Silurus microdorsalis, was examined histologically regarding water temperature and day length of habitat, gonadosomatic index (GSI), and development characteristics of female and male gonads. The maximum GSI value was found in May, $1.23{\pm}0.33$ and $11.77{\pm}3.23$ for male and female respectively (habitat water temperature $21.5^{\circ}C/13.59hr$ day length). On the other hand, the minimal level was $0.63{\pm}0.10$ in July ($26.5^{\circ}C/14.17$) for male and $1.36{\pm}0.08$ in October ($20^{\circ}C/11.2hr$) for female. We compared and calculated the stages of testis and ovary development process in order to determine the germ cell development characteristics and the reproductive cycle. According to results, we classified the annual reproductive cycle of the slender catfish into five stages: Growing phase (December-February), Mature phase (March-April), Ripe and spawning phase / Releasing phase in male (May-June), Degenerative phase (July-August), and Resting phase (September-November).

• 한국발생생물학회지:발생과생식
• /
• 제24권3호
• /
• pp.225-230
• /
• 2020

This study reports the presence of mature and bi-sexual phase gonads in red spotted grouper, Epinephelus akaara after less than a year of cultivation in a commercial indoor tank and a net cage. In December 2018, juveniles were placed in an indoor tank and cultured for five months. In June 2019, the fish were transferred to a net cage and cultured until September. The rearing temperatures ranged from 19.86℃-24.65℃ in the indoor tank and 21.86℃-27.65℃ in the net cage. During the net cage culture period, specimens were randomly selected for histological gonad examination. The highest gonadosomatic index (GSI) value was measured in July (3.38±2.53), and dramatically decreased in August (0.44±0.21) and September (0.42±0.30). In July, some mature fish showed signs of vitellogenic stage oocyte development (vitellogenic and oil droplet stage oocytes), but immature fish were in an early developmental stage containing peri-nucleolus stage (PNS) oocytes. Bi-sexual phase gonads containing spermatocytes and spermatids were observed in the lumen and several PNS oocytes. By August and September, most specimens showed early-stage ovary development. However, mature testis (in August) and bi-sexual phase gonads (in September) were also observed. These results provide evidence for early puberty and hermaphroditism in the red spotted grouper.