• Korean Journal of Poultry Science
• /
• v.37 no.4
• /
• pp.383-388
• /
• 2010

The chicken eye can discriminate light color, and different light wavelengths may affect reproduction ability. This study was carried out to identify effect of monochromatic light using light emitting diode (LED) in laying hens. Chickens were exposed to white light (WL), blue light (BL), yellow light (YL), green light (GL) and red light (RL) made by using LED as well as incandescent light (IL) (control). All light sources were equalized to a light intensity of 20 lux. The results indicated that the age of first egg laying and 50 % egg laying in laying hens treated under RL is significantly younger than under other lights (P<0.05). And the ovary weight of laying hens reared under RL is significantly heavier than under other at from 16 to 20 wks (P<0.05). The largest number of eggs production was produced in a group with treated with RL by 59 wks of age compared with any other group. The egg weight of YL was greater than other treatment groups from 26 to 45 wks (P<0.05). The egg shell from hens treated with RL was the strongest and thickest at 20 wk (P<0.05). These results suggest that the egg quality of laying hens reared in different spectrum of LED can be different and RL may enhance the laying performance.

• Reproductive and Developmental Biology
• /
• v.35 no.1
• /
• pp.33-45
• /
• 2011

Heat shock protein 90 (Hsp90) is ATPase-directed molecular chaperon and affects survival of cancer cell. Inhibitory effect of Hsp90 by inducing cell cycle arrest and apoptosis in the cancer cell was reported. However, its role during oocyte maturation and early embryo development is very insufficient. In this study, we traced the effects of Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), on meiotic maturation and early embryonic development in pigs. We also investigated several indicators of developmental potential, including structural integrity, gene expression (Hsp90-, cell cycle-, and apoptosis-related genes), and apoptosis, which are affected by 17-AAG. Then, we examined the roles of Hsp90 inhibitor on viability of primary cells in pigs. Porcine oocytes were cultured in the NCSU-23 medium with or without 17-AAG for 44 h. The proportion of GV arrested oocytes was significantly different between the 17-AAG treated and untreated group (78.2 vs 34.8%, p<0.05). After completion of meiotic maturation, the proportion of MII oocytes was lower in the 17-AAG treated group than in the control group (27.9 vs 71.0%, p<0.05). After IVF, the percentage of penetrated oocytes was significantly lower in the 17-AAG treated group (25.2%), resulting in lower normal pronucleus formation (2PN of 14.6%). Therefore, the inhibition of meiotic progression by Hsp90 inhibitor played a critical role in fertilization status. Porcine embryo were cultured in the PZM-3 medium with or without 17-AAG for 6 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without 17-AAG. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that the number of containing fragmented DNA at the blastocyst stage increased in the 17-AAG treated group compared with control (7.5 vs 4.4, respectively). Blastocysts that developed in the 17-AAG treated group had low structural integrity and high apoptotic nuclei than those of the untreated control, resulting in decrease the embryonic qualities of preimplantation porcine blastocysts. The mRNA expressions of cell cycle-related genes were down-regulated in the 17-AAG treated group compared with control. Also, the expression of the pro-apoptotic gene Bax increased in 17-AAG treated group, whereas expression of the anti-apoptotic gene Bel-XL decreased. However, the expression of ER stress-related genes did not changed by 17-AAG. Cultured pESF cells were treated with or without 17-AAG and used for MIT assay. The results showed that viability of pESF cells were decreased by treatment of 17-AAG ($2{\mu}M$) for 24 hr. These results indicated that 17-AAG decreased cell proliferation and increased cell death. Expression patterns Hsp90 complex genes (Hsp70 and p23), cell cycle-related genes (cdc2 and cdc25c) and apoptosis-related genes (Bax and Bcl-XL) were significantly changed by using RT-PCR analysis. The spliced form of pXbp-1 product (pXbp-1s) was detected in the tunicamycin (TM) treated cells, but it is not detected in 17-AAG treated cells. In conclusion, Hsp90 appears to play a direct role in porcine early embryo developmental competence including structural integrity of blastocysts. Also, these results indicate that Hsp90 is closely associated with cell cycle- and apoptosis-related genes expression in developing porcine embryos.

• Journal of The Korean Association For Science Education
• /
• v.20 no.3
• /
• pp.396-410
• /
• 2000

In this study, the concept presentation form, the content coherence of sub-dimensional concepts and the number of concepts of the 6th and the 7th Korean curriculum were analyzed comparing the guide to developing the secondary biology curricula to develop biological literacy with BSCS. According to the result, the discrimination between concept levels in the frame of contents of the Korean curricula is insufficient, because each of concepts presented in the knowledge domain as upper level and sub-dimensional concept elements as lower level are simply arrayed. Considering too much concepts of ecosystem, genetics, reproduction and metabolism, there should be an effort to reform the biological curriculum to include concepts evenly, not in the biased state, to reflect all the 6 unifying principles by BSCS for developing students' biological literacy. Finally there should be an effort to reflect the characteristics of each subjects concretely among Science 10, Biology I and Biology IT in the 7th curriculum considering the result that essential concepts to develop biological literacy are presented more in some principles of Biology II than Biology I. Thinking the results of the present study, concrete discussions should be made to set up the standard reference about biological literacy and to present essential concepts for teaching and learning to develop it in the process of biology textbook development for meeting the 7th Korean curriculum and in the development of 8th Korean curriculum in advance.

• Development and Reproduction
• /
• v.9 no.2
• /
• pp.95-103
• /
• 2005

Reproductive cycle, gonadosomatic index(GSI), egg diameter composition, first sexual maturity, sexually matured length(50% of first sexual maturity), and sex ratio of Amusium japonicum japonicum, were investigated by histological observations and morphometric data. Samples were collected monthly from the subtidal zone of Sogwipo, Jejudo, Korea, for two years. The sun and moon scallop Amusium japonicum japonicum is dioecious. Monthly variation in the GSI showed similar patterns with the reproductive cycle. Ripe oocytes were about $70{\sim}90\;{\mu}m$ in diameter and had thick egg membranes. The spawning period was from November to January, and the main spawning occurred between November and December when the seawater temperature was relatively low. From monthly changes in egg diameter composition, the spawning period was once a year, although the number of spawning frequencies is assumed to occur more than twice during the spawning season. The reproductive cycle of this species could be divided into five successive stages: early active stage(April to June), late active stage(June to September), ripe stage(October to November), spawning stage(November to January), and spent/resting stage(February to April). First sexual maturities in female and male scallops ranging from 85.1 to 90.0mm in shell length were over 50% and they were 100% for scallops over 90.0mm in shell length. In this population, sexually matured shell lengths(50% of rate of group maturity) in females and males were 86.96 and 86.59mm, respectively. The female to male sex ratio among individuals over 85.1mm in shell length was not significantly different from 1:1($X^2=0.18$, p>0.05). No evidence of hermaphrodite was found in histological sections of any scallop examined.

• Development and Reproduction
• /
• v.12 no.1
• /
• pp.31-39
• /
• 2008

Neural tissue has limited intrinsic capacity of repair after injury, and the identification of alternate sources of neural stem cells has broad clinical potential. We isolated mesechymal-like stem cells from human adipose tissues (AT-MSCs), and studied on transdifferentiation-promoting conditions in neural cells. Dopaminergic and cholinergic neuron induction of AT-MSCs was also studied. Neural differentiation was induced by adding bFGF, EGF, dimethyl sulphoxide (DMSO) and butylated hydroxyanisole(BHA) in N2 Medium and N2 supplement. The immunoreactive cells for $\beta$-tubulin III, a neuron-specific marker, GFAP, an astrocyte marker, or Gal-C, an oligodendrocyte marker, were found. AT-MSCs treated with bFGF, SHH and FGF8 were differentiatied into dopaminergic neurons that were immunopositive for TH antibody. Differentiation of MSCs to cholinergic neurons was induced by combined treatment with basic fibroblast growth factor (bFGF), retinoic acid (RA) and sonic hedgehog (Shh). AT-MSCs treated with DMSO and BHA rapidly assumed the morphology of multipolar neurons. Both immunocytochemistry and RT-PCR analysis indicated that the expression of a number of neural markers including neuro D1, $\beta$-tubulin III, GFAP and nestinwas markedly elevated during this acute differentiation. While the stem cell markers such as SCF, C-kit, and Stat-3 were not expressed after preinduction medium culture, we confirmed the differentiation of dopaminergic and cholinergic neurons by TH/$\beta$-tubulin III or ChAT/ $\beta$-tubulin III positive cells. Conclusively, AT-MSCs can be differentiated into dopaminergic and cholinergic neuronsand these findings suggest that AT-MSCs are alternative cell source of treatment for neurodegenerative diseases.

• Development and Reproduction
• /
• v.14 no.4
• /
• pp.297-306
• /
• 2010

Tributyltin (TBT), an endocrine disrupting chemical, has been reported to decrease testicular function by causing apoptosis in the testis, but this mechanism is not fully understood. Thus, in this study we examined whether TBT induces adipogenesis of the Leydig cells to find out the correlation between adipogenesis and apoptosis in the testis. Three week old SD male rats were orally administrated with sesame oil, 1 mg/kg of TBT, or 10 mg/kg of TBT daily for 1 week and weighed after administration. The testes obtained on day 8 were weighed and stained with BODIPY and TUNEL kit. Using total RNA extracted from the isolated Leydig cells, adipogenesis and apoptosis-related genes were analyzed by real-time PCR. The testicular weights of the rats treated with 10 mg/kg TBT were significantly decreased compared to those in the control rats treated with sesame oil. As a result of BODIPY staining, the number of Leydig cells stained with BODIPY was increased in the rats treated with 10 mg/kg TBT compared with the control rats. Similar to BODIPY staining results, the TUNEL assay showed that the apoptosis of Leydig cells was increased in TBT treated rats. The results of the gene expression analysis in the Leydig cells showed that the expression of adipogenesis-related genes (PPAR${\gamma}$, aP2, Perilipin, CD36) and apoptosis-related genes (TNFRSF1A, TNFSF10) was increased after TBT administration. The present study demonstrates that TBT induces the expression of adipogenesis-related and apoptosis-related genes in the Leydig cells leading to adipogenesis and apoptosis in the testes. These results suggest that the dysfunction of Leydig cells by TBT exposure may cause a loss in testicular function.

• Ocean and Polar Research
• /
• v.37 no.1
• /
• pp.49-59
• /
• 2015

Spatial variation in the reproductive effort of Manila clam Ruditapes philippinarum is often closely associated with variation in the seawater temperature and food availability, which determines gonad maturity and the quantity of gamates produced during spawning. Previous studies also have reported that severe infection by the protozoan parasite Perkinsus olseni exerts a negative impact on clam reproduction, retarding gonad maturation or decreasing the reproductive effort. In the present study, we investigated impacts of P. olseni infection on the reproductive condition of Manila clam during a spawning season. Histology revealed that 54% of female clams in Wando off the south coast were in spawning, while only 10% of the female from Gomso and 0% of the female from Seonjaedo in Gyeonggi bay off the west coast were engaged in spawning at the end of May in 2004. Ray's fluid thioglycollate media (RFTM) assay was applied to assess P. olseni infection and indicated that the infection intensity in Wando ($3,608,000{\pm}258,000cells/g$ wet tissue) was significantly higher than the levels in Gomso ($1,305,000{\pm}106,000cells/g$ wet tissue) and Seonjaedo ($1,083,000{\pm}137,000cells/g$ wet tissue, p < 0.001). The size of the ripe female follicle determined from histology was significantly smaller in Wando ($0.032mm^2$) compared to the sizes in Gomso ($0.059mm^2$) and Seonjaedo ($0.052mm^2$, p < 0.05). Accordingly, the number of ripe eggs in the follicle was significantly fewer among clams in Wando (14) compared to the numbers determined in Gomso (23) and Seonjaedo (22). The absolute quantity of egg in ripe clams from Wando (31.01 mg) was also significantly smaller than Seonjaedo (61.79 mg) and Gomso (133.3 mg). Quantity of total protein, carbohydrate, and lipid in the tissue in the Wando samples was significantly smaller than the quantities determined in Gomso and Seonjaedo (p < 0.001). The observed poor reproductive condition and proximate tissue composition of the females in Wando were, in part, explained by the extremely high level of the parasites, sapping the ability to store energy in the host tissues, which is used in tissue growth and the egg production.

• Journal of Ginseng Research
• /
• v.24 no.1
• /
• pp.8-17
• /
• 2000

Estrogen can influence on the expression of behaviors not associated directly with reproduction, including learning and memory. Recently estrogen has received considerable attention for its effects on neuroprotection and neural circuits in brain areas associated with cognition. Although estrogen replacement therapy may be helpful to postmenopausal women, it also results in a number of harmful side effects. Ginseng also has steroidal qualities and contains several ginsenoside components which have similar backbone structure to estrogen. The objectives of this experiment were 1) to examine the effects of estrogen and 2) to investigate the effects of ginsenosides as estrogenic agent on learning and memory using the Morris water maze, a traditional experimental task for spatial memory. In the experiments designed here, ovariectomized mice were implanted subcutaneously with Sila, itic capsules containing 17${\beta}$-estradiol (100∼250 $\mu\textrm{g}$/$m\ell$), panaxadiol (PD) and panaxatriol (PT) saponins (15∼100 $\mu\textrm{g}$/$m\ell$) diluted with sesame oil. In the first set of experiment, the effects of estradiol on learning and memory during the Morris water maze was examined. When estradiol was delivered via Silastic capsules following training improved spatial memory performance in ovariectomized female mice. In the second set of experiment, three different PD and PT saponin concentrations were delivered via Silastic implants to ovariectomized female mice and their effects were compared with estrogenic effects. Results of three separate experiments demonstrated that estradiol, PD and PT administrated by Silastic implants for 2 weeks prior to water maze training significantly improved spatial memory performance compared to ovariectomized (OVX) mice, as indicated by lower escape latency over trial. The positive effect of estradiol suggests that estrogen can affect performance on learning and memory. In addition, the positive effect of PD and PT saponins suggest that ginsenosides have an estrogen-like effects in mediating learning and memory related behavior action.

• Journal of the Korean Geographical Society
• /
• v.28 no.3
• /
• pp.213-226
• /
• 1993

In Korea, the urban studies of geography have mainly dealt with such a series of research as system of urban place and internal structure of urban area. The existing studies have been carried out with ecological approach. Ecologists, now a days, regard organiation and transfor-mation of the urban space as the process of invasion, succession, and segregation. However it is more proper that cities should be considered not as fragmantary objects, as some ecologists insist, but as synthetic ones in social structure. This research, with adopting a case of the renewasl of central area in Seoul, tried to make it clear that the formation and transition of the city is a product of social structure and examined polical and economic logic which exists in variation of urban space in detail. The results of this study are as follows; Urban renewal of central area is closely related with production and reproduction in capitalist society. In urban center, as business activities had increased since 1973 due to decen-tralization of production process, the necessity of reorganizing the land use in existing central area accordingly increased. The urban renewal program of central area in Seoul was inrroduced under such situation. The urban renewal of central area reflecting the capital logic has changed the central area with six hundred year's tradition. From the urban renewal of central area, not only was the central area, which traditionally had been mixed with various fun-ctions, simplified into the unitary area of busi-ness, but also physical landscape changed. As the land lot in renewal area expanded into regular shape, buildings became larger and taller. The program tremendously raised the price of related area. Aiming at these profits caused by the raised price, a great number of capitalists participated in the program. And as the benefit ratio of the manufacture sector continuously dropped with the economic recession, the pro-gram was carried out much more vigorously. That was because the idle capital accumulated during the recession was invested in property sector and was self-proliferated. The urban renewal raised the land value of central area and drove out the people living in this area. The people moved into the whole parts of the city resulting diffused squatter settlements. And the urban changes in central area were results of the policy of municipal authorities, who supported and systematized the changes lawfully and administratively, as well as reali-zation of capital logic. Due to the renewal policies of central area in Seoul, much more renewals by the only capitalists were carried out than those by the people themselves living in that area. The integration of land ownership in the law of urban renewal shows the reason of that. Moreover, the law allows the third deve-loper to participate in the tasks and admits the land expropriation rights. The municipal autho-rities guaranteed the profitability of the tasks through finacial aid, tax benifit, and relaxation of regulations for construction. As examined above, the changes in the land use of urban space have been led not by the ecological process of development of the city itself, but by the restructuring of capitalism and the intervention of the government authorities.

• Journal of Korean Society of Forest Science
• /
• v.107 no.3
• /
• pp.237-244
• /
• 2018

This study was carried out in order to secure basic data of seedling mass propagation technique of Rhododendron mucronulatum which is the native tree species of Korea by surveying the characteristics of its fruit and seed. The fruits were collected at Mt. Goryeo in Ganghwa-gun on different dates in 2013; August 26th, September 5th, September 12th, October 4th. The seed germination test was carried out at 5, 10, 15, 20, 25 and $30^{\circ}C$. Moisture content of the fruit was highest (54.5%) in the fruit collected on September 5th. Number of the seeds in a fruit was 91.3 to 116.3, regardless of the collection date. Seed length was highest ($1947.4{\mu}m$) in the seeds collected on October 4th and seed width was highest ($727.3{\mu}m$) in the seeds collected on September 12th. Germination rate of the seeds was highest at $25^{\circ}C$ regardless of the seed collection date, which showed the highest value(27.3%) in the seeds collected September 12th. Meanwhile, the seeds were not germinated not at all at 5, 10 and $30^{\circ}C$. $T_{50}$ and mean germination time of the seeds got shorter at the higher temperature. Germination uniformity got lower when the collection date got later. Germination speed of the seeds was fastest at $25^{\circ}C$. According to the results of this study, it seems that the appropriate time to collect fruit and seed is between September 12th and October 4th, and the appropriate temperature for the seed germination is $25^{\circ}C$.