• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.66-67
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• 2004

• The Optical Journal
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• s.103
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• pp.21-25
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• 2006

올해 국내 디카 성장률은 작게는 20%에서 30% 정도로 약 230만대 내외의 시장이 될 것으로 보인다. 올해 역시 식을 줄 모르는 디지털카메라의 인기 행진이 계속되면서 특히 지난해부터 본격화된 초창기 300만 화소 이하의 저화소대 디카를 구매했던 소비자들의 교체수요를 비롯한 시장 선점을 위한 메이커간의 경쟁이 그 어느 때보다 치열할 전망이다. 예전처럼 단순 화소 경쟁이 아닌 다양한 기능으로 차별화를 꾀하는 메이커들의 경쟁과 함께 국내 디카시장은 본격 성숙기에 들어설 것으로 보인다.

• Journal of Embryo Transfer
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• v.22 no.3
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• pp.155-160
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• 2007

During in vitro culture of mammalian oocytes and embryos, the cells are exposed to the risks that cause cell injury or death. Numerous studies have been reported that the cell injury may be induced by the action of free radicals generated by auto-oxidation. This study was undertaken to investigate the optimal culture condition system for in vitro culture of porcine embryos. We first evaluated the effect of culture media on the porcine embryo development. NCSU-23 and PZM-5, culture medium tested, were failed to produce significant difference on the rate of blastocyst formation. In NCSU-23, the developmental rate was slightly higher than that in PZM-5. During in vitro maturation (IVM), fertilizaton (IVF), and culture (IVC) under 5 or 20% oxygen ($O_2$), the rates of cleavage and development were insignificantly different from each other under our culture condition (20% $O_2$, in NCSU-23), the mean cell number per blastocyst was $40{\pm}10$. These results showed that medium and $O_2$ concentration had no significant effect on the development of porcine embryos.

• Journal of Embryo Transfer
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• v.17 no.3
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• pp.195-201
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• 2002

This study was to assess the developmental capacity of oocytes matured in vitro after 20, 15, 10, 5 and 0 days of organ culture when ovaries were isolated from juvenile mice at 0-, 5-, 10-,15- and 20-day old, respectively, and to develop in vitro culture system that observed a view to morphology of ovaries and nucleus maturation of oocytes. The size of ovaries decreased 35.9%, 8.7%, 1.2% and 14.4% after 20, 15, 10, 5 days of organ culture when the ovaries were isolated from 0-, 5-, 10 and 15-day old mice, respectively. After organ culture, the recovery rates, diameters of oocytes and the number of oocytes progressed from GV to MII were increased as increasing age of mice.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.885-890
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• 2003

This study was conducted to estimate the growth curve parameters of 253 heads of F2 population produced by inter-crossing F1 from Korean Native boars and Landrace sows, and to estimate the effects of Leptin receptor gene(LEPR) on their growth characteristics. Growth curve parameters were estimated from nonlinear regression using Gompertz model individually. Average mature weight and average maturing rate estimated were 179.69${\pm}$4.40kg and 0.3103${\pm}$0.0043, respectively. The effect of sex was insignificant for all the parameters estimated from Gempertz model(p〉.05), and the effect of calving group was significant for mature weight and maximum growth rate at inflection point (p〈.05). The effect of LEPR genotype were significant for all the growth curve parameters(p〈.05). According from the results of the least squares means of growth curve parameters by LEPR genotypes, mature weight and point of inflection were highest in genotype AA in which the maturing rate was the lowest, and were lowest in genotype DD in which maturing rate was the highest, reversely.

• Development and Reproduction
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• v.10 no.2
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• pp.115-125
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• 2006

The present experiment was performed to confirm the effects of selenium on maturation and viability of mouse oocyte. Maturation of oocytes was observed by microscope, Germinal vesicle breakdown(GVBD) and polar body formation(PB) were confirmed at 2.5, 13 hours after in vitro culture. Viability of oocytes was observed by microscope. Normal and abnormal oocytes were distinguished by morphological change in vitro culture for 72 hours. Glutathione(GSH) content of collected oocytes from individual stage also was measured by glutathione assay using spectrophotometer. The results obtained were as follows; The low concentration of selenium($0.005\;{\mu}g/mL{\sim}0.5\;{\mu}g/mL$) increased the maturation rate of germinal vesicle(GV) oocytes to GVBD and PB oocytes. The high concentration of selenium($5\;{\mu}g/mL$) decreased the maturation rate. The low concentration of selenium increased the viability rate of PB oocytes. The high concentration of selenium did not affect the viability rate. The low concentration of selenium increased the GSH content in PB oocytes. The high concentration of selenium decreased GSH content. GSH content in PB oocyte was much higher than that in GVBD oocyte. The results indicate that the low concentration of selenium increases the maturation rate by helping quality elevation of oocyte and minimizing damages of oxidative stress generated from metabolism process. The low concentration of selenium also increases the viability rate by increasing GSH content.

• Korean Journal of Animal Reproduction
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• v.27 no.2
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• pp.115-123
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• 2003

The present study was carried out to examine the effect of catalase (CAT) on in vitro maturation (IVM) of porcine follicular oocytes and oxygen concentration with CAT on in vitro development (IVD) of porcine IVM/IVF embryos. The results were summarized as follows - 1 . The rates of nuclear maturation, penetrated oocytes, pronucleus formation rates, polyspermic oocytes and mean numbers of the penetrated sperm were significantly lower in oocytes matured with 100, 500 and 1,000 units/ml CAT than those of central groups (P>0.05). 2. The rates of blastocyst formation and total cell numbers of blastocyst at day 7 after in vitro fertilization were significantly lower in CAT treatment groups than those of the central groups (P>0.05). 3. There were not significant difference in the blastocyst development and total cell numbers of blastocyst on in vitro culture of NCSU-23 media with 0, 100, 500 and 1000 units/ml CAT under the 5% and 20% $O_2$ concentrations. These results suggested that the addition of CAT was not helpful for porcine oocyte maturation and further development, also the rates of blastocyst formation and total cell numbers of blastocyst at day 7 of porcine IVM/IVF embryos were not significantly different in the NCSU-23 culture medium under the 5% and 20% $O_2$ concentrations.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.295-301
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• 2020

In this study, we aimed to investigate the changes in the catch rate of Monochamus saltuarius, based on sexual maturation by using aggregation-sex pheromone traps. Ovariole development of caught M. saltuarius females was compared to that of the ones not caught using traps. In a mesh cage set up at the Hongneung experimental forest, we placed a multi-funnel trap with or without an aggregation-sex pheromone lure. M. saltuarius adults, which emerged from pine logs, were grouped in four according to the emergence dates (0, 1, 7, and 10 days after emergence [DAE]). We released beetles into the mesh cage to investigate the catch rate using the traps. In each group, a total of 80 beetles (20 beetles × 4 replications) were tested, making it a total of 320 beetles. Among the four groups, M. saltuarius adults in the 7 DAE group were caught more frequently using the traps, especially with a pheromone lure; the other groups showed a low catch rate. A similar number of female and male beetles were caught using the traps. Regarding ovariole development, all the female adults in the 0 and 1 DAE groups were immature, while those in the other two groups were completely developed. Therefore, aggregation-sex pheromone traps might have a limitation in the prevention of pine wilt disease because of the transmission of pine wood nematode during maturation feeding of newly emerged M. saltuarius adults. However, aggregation-sex pheromone traps can be effective for collecting sexually mature M. saltuarius adults, for the investigation of seasonal occurrence of beetles in forests.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.4
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• pp.293-303
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• 2007

Objective: Previously, we identified differentially expressed genes between GV and MII stage mouse oocytes using ACP technology. When we study one of GV selective genes, Obox family, we found Obox4 mRNA expression in ovaries that has been reported as expressed exclusively in testis. Therefore, this study was conducted for characterization and functional analysis for Obox4. Methods: Expression of Obox4 mRNA was examined in gonads and oocytes by RT-PCR. To determine the role of Obox4 in oocyte maturation, Obox4 dsRNA was microinjected into the cytoplasm of GV oocytes followed by 16 h of incubation in the plain medium or by 24 h of incubation in the medium containing IBMX. After RNAi, phenotypes and maturation rates were observed, change in mRNA expression was evaluated, and chromosomal status was confirmed by orcein staining. Results: Obox4 has minimal expression in the ovary compared to that of the other family members. When oocytes were cultured for 16 h in M16 medium after RNAi, maturation rate was not changed significantly, compared with that of non-injected or buffer-injected control oocytes. Surprisingly, however, when oocytes were cultured for 24 h in M16 containing IBMX, in which oocytes were supposed to arrest at GV stage, Obox4 RNAi oocytes were advanced to MI and MII. Spindle structure was disappeared and the chromosomes were condensed in the oocytes after Obox4 RNAi. Conclusions: This is the first report on the expression of Obox4 in the ovary and oocytes. Results of the study suggest that Obox4 plays a crucial role in spindle formation and chromosome segregation during meiosis in oocytes. In addition, Obox4 may play an important role in cAMP-dependent signal cascades of GV-arrest in mouse oocytes.

• Korean Journal of Animal Reproduction
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• v.27 no.2
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• pp.125-133
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• 2003

The present study was carried out to examine the effect of $\beta$-Mercaptoethanol ($\beta$-ME) on in vitro maturation (IVM) of porcine follicular oocytes and oxygen concentration with $\beta$-ME on in vitro development (IVD) of porcine IVM/IVF embryos. The results were summarized as follows. 1. The rates of nuclear maturation, penetrated oocytes, polyspermic oocytes, pronucleus formation and mean numbers of the penetrated sperms were not significantly different using NCSU-23 maturation media for 0, 25, 50 and 100 $\mu$M $\beta$-ME (P>0.05). 2. The rates of blastocyst formation at day 7 after in vitro fertilization were higher in oocytes matured with 25 $\mu$M $\beta$-ME (25.4$\pm$0.9%) than in those matured with 0 (14.5$\pm$1.6%), 50 (17.3$\pm$1.7%) and 100 $\mu$M (12.4$\pm$1.3%) (P<0.05). However, no differences ware found in total cell numbers of blastocyst among the treatments. 3. The rates of blastocyst formation at day 7 after in vitro fertilization were higher in the NCSU-23 Culture medium With 25 $\mu$M $\beta$-ME (23.6$\pm$2.8%) than in those Cultured With 0 (15.4$\pm$4.4%), 12.5 (17.5$\pm$2.3%) and 50 $\mu$M $\beta$-ME (18.6$\pm$2.1%) Under the 5% and 20% $O_2$ Concentrations (P<0.05). However, no differences was found in total cell numbers of blastocyst among the treatments. These results suggested that the addition of 25 $\mu$M $\beta$-ME in the IVM/IVD media were effective on the porcine embryo production. However, the rates of blastocyst formation and total cell numbers of blastocyst at day 7 of porcine IVM/IVF embryos were not significantly different in the NCSU-23 culture medium under 5% and 20% 02 concentrations.