• Journal of Plant Biotechnology
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• v.3 no.2
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• pp.101-106
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• 2001

In order to establish efficient plant regeneration from embryogenic suspension cultures of soybean, Glycine max L, we examined the effects of auxin type and concentration, cytokinin type and concentration, and amino acid type and concentration on the growth of embryogenic clumps from induced callus, and the effect of desiccation of mature somatic embryos obtained from these clumps on the frequency of somatic embryo germination. Embryogenic callus was induced from the edge of the cotyledons cultured on MS medium containing 6% sucrose, 40 mg/L 2,4-D, 0.2% gelrite and pH 5.7. The growth of embryogenic clumps was best in early staged, embryogenic callus that was placed in suspension culture of MS medium containing 5 mg/L 2,4-D and 0.5 mg/L asparagine. Single somatic embryos were isolated from the clumps and plated on the same medium for maturation. When the mature single somatic embryos were desiccated for 96 h, somatic embryo germination came up to approximately 90%. The plantlets germinated after embryos desiccation for 2 weeks were transfered to MS medium containing 3% sucrose,0.2% gelrite and pH 5.7.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.11
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• pp.1545-1552
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• 2013

This study was conducted to investigate the effects of Trichostatin A (TSA) on cumulus expansion during mouse oocyte maturation. TSA treatment inhibited cumulus expansion and significantly reduced the cumulus expansion index (CEI) (p<0.05). To determine the underlying mechanism, the expression levels of several key factors that play crucial roles in cumulus expansion including components of extracellular matrix (ECM) (Has2, Ptgs2, Ptx3, and Tnfaip6) and Growth differentiation factor 9 (GDF9) were measured in control and TSA treated samples by real-time PCR. The effect of TSA on ERK phosphorylation (p-ERK1/2) in cumulus cells and GDF9 protein level in fully grown oocytes (FGOs) were detected by Western blotting. The expression levels of the ECM genes were significantly decreased (p<0.05) by TSA treatment while GDF9 expression did not response to TSA (p>0.05). TSA treatment blocked the activation of ERK1/2 (p<0.05) and had no significant effect on GDF9 protein expression (p>0.05). Collectively, these results suggested that TSA treatment altered ECM gene expression and blocked ERK1/2 activation to inhibit cumulus expansion in the mouse.

• Journal of Ecology and Environment
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• v.33 no.1
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• pp.59-65
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• 2010

Because seagrass production significantly contributes to the biodiversity and production of coastal and estuarine ecosystems, accurate estimation of seagrass productivity is a critical step toward understanding the ecological roles of seagrass in these ecosystems. To develop an accurate and effective method of measuring seagrass productivity, we estimated leaf productivity of eelgrass (Zostera marina) on the southern coast of Korea using three methods, the conventional leaf marking method, the elongation-mass method (Short '87 method), and the plastochrone method. In each season, shoots were pierced through the bundle sheath using a hypodermic needle and were collected after 2-4 weeks had elapsed to estimate their productivity. The leaf elongation and the leaf plastochrone intervals varied significantly among seasons. On an annual basis, the conventional leaf marking method showed the lowest leaf productivity estimates compared to the elongation-mass method and the plastochrone method, suggesting that the conventional leaf marking method underestimated leaf productivity as it ignored leaf maturation processes and new leaf growth within the sheath. Since the elongation-mass method considered leaf maturation processes, this method produced higher leaf productivity estimates than the conventional leaf marking method. On an annual basis, the plastochrone method produced the highest leaf productivity estimates. Below-ground productivity, which can be easily estimated using the plastochrone method, ranged between 3.29 and 5.73 (mg dry weight $shoot^{-1}\;day^{-1}$) and accounted for about 17.8% to 30.3% of total productivity. Because of the high contributions of below-ground productivity to total seagrass production, we suggest that the plastochrone method is an effective and simple technique for assessing both above- and below-ground productivities.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.1
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• pp.20-33
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• 2017

Objective: Superstimulatory treatment of one-month-old lambs can achieve synchronous development of numerous growing follicles. However, these growing follicles cannot complete maturation and ovulation. Oocyte maturation and competence are acquired during follicular development, in which granulosa cells play an essential role. Methods: In this study, we applied RNA sequencing to analyze and compare gene expression between prepubertal and adult superstimulated follicle granulosa cells in sheep. Results: There were more than 300 genes that significantly differed in expression. Among these differently expressed genes, many extracellular matrix genes (EGF containing Fibulin Like Extracellular Matrix Protein 1, pentraxin 3, adrenomedullin, and osteopontin) were significantly down-regulated in the superstimulated follicles. Ingenuity pathway and gene ontology analyses revealed that processes of axonal guidance, cell proliferation and DNA replication were expressed at higher levels in the prepubertal follicles. Epidermal growth factor, T-Box protein 2 and beta-estradiol upstream regulator were predicted to be active in prepubertal follicles. By comparison, tumor protein P53 and let-7 were most active in adult follicles. Conclusion: These results may contribute to a better understanding of the mechanisms governing the development of granulosa cells in the growing follicle in prepubertal sheep.

• Journal of Plant Biotechnology
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• v.7 no.1
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• pp.75-80
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• 2005

Eleutherococcus senticosus (also called Acanthopanax senticosus), belonging to Araliaceae family, has been used as an important medicinal woody plant. Mature seeds of Eleutherococcus senticosus have rudimentary (extremely immature) zygotic embryos and require a long-term stratification for about 18 months to induce germination. Here, through the methods of endosperm removal and other exogenous treatments, we investigated the factors for inducing rudimentary embryos by in vitro culture, Rudimentary zygotic embryos in seeds were at globular to heart-shaped stage at about $250{\mu}m$ in length just after harvest of fruits. When the seeds without testa were cultured on 1/2 MS (Murashige and Skoog 1962) medium, they did not germinate regardless of medium and sucrose concentrations but the removal of endosperm tissue markedly stimulated the growth of rudimentary zygotic embryos. The embryo reached ear-lier maturation, once when the endosperm surrounding the rudimentary embryos was removed. Rudimentary zygotic embryos developed cotyledons within 3 weeks of culture after endosperm emoval. However, post-mature zygotic embryos failed to germinate though they were morphologically normal, indicating another dormancy of embryos. $GA_3\;(2.0\;\cal{mg/L})$ and/or charcoal ($0.2\%$) treatment rapidly enhanced the germination of zygotic embryos. These results suggest that E. senticosus seeds have double dormancy; i. e. morphological rudimentary dormancy influenced by surrounding endosperm and physiological dormancy after post-maturation of zygotic embryos. Based on the above findings, we established the rapid germination of rudimentary zygotic embryos by in vitro culture of excised seeds with endosperm removal and $GA_3$ treatment.

• The Korean Journal of Ecology
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• v.19 no.2
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• pp.107-123
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• 1996

The position effects on the abortion of flowers, fruits, and ovules were examined in relation to the resource limitation hypothesis using a temperate legume species, Vicia cracca. Fifty plants were randomly sampled from a natural population located at the Belmont Conservation Site in Belmont, MA, USA. Due to indeterminant growth and acropetal flowering of this species, the position of flower or fruit on the plant was able to be coded by the combination of architectural levels such as plant half (lower and upper half) and inflorescence half (lower and upper half) within each plant half. Overall, only 17.3% of the flowers on an inflorescence began to develop into fruits, while overall 36.0% of the fruits initiated failed to mature. Consequently, 11.5% of the flowers successfully matured into fruits. The mean flower number per inflorescence differed significantly among plants as well as between plant halves. Although the probability of fruit initiation was higher in the lower halves of both plant and inflorescence than in the upper halves of the latter, fruit abortion rate differed significantly only between plant halves. The overall mean seed set was 33.6%, implying that about two out of six ovules in a fruit matured into seeds. The seed set was independent of both plant identity and architectural level unlike other reproductive characters examined. When the ovule developmental stage was examined on data pooled over all fruits, the proportion of ovules in varying developmental stages decreased in order of early abortion, seed maturation, late abortion, and seed predation (48.4, 34.9, 12.2, and 4.5%, respectively). A within-fruit ovule position was also used as a class variable for the analysis of position effects on ovule development. All architectural levels considered exerted singificant influence over the ovule development. In particular, ovule development was strongly affected by the within-fruit ovule position. Ovules in both extreme ends within a fruit tended to abort early, while those in the middle position were more likely to mature into seeds. The strong position effects detected from the flowering to seed maturation stage were interpreted as an indication of competitive interaction among reproductive characters which are largely constrained by plant architecture.

• Imaging Science in Dentistry
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• v.50 no.3
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• pp.209-216
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• 2020

Purpose: In India, the age of 14 years is the legal age threshold for child labour. Therefore, in suspected instances of child labour, age assessment plays a crucial role in determining whether a violation of the law on the employment of children has occurred. The aim of this retrospective cross-sectional study was to assess the discriminatory ability of stages of cervical vertebral maturation (CVM) in predicting the legal age threshold of 14 years. Materials and Methods: Routinely taken lateral cephalograms from 408 subjects aged 10 to 18 years were evaluated retrospectively using the CVM stages described by Baccetti et al. Descriptive statistics, accuracy, sensitivity, specificity, positive and negative predictive values, and likelihood ratios were calculated for stages 2, 3, and 4 of CVM. Results: Real age increased as the CVM stage gradually increased. The results of 2×2 contingency tables showed that CVM stage 4 produced an accuracy of 71% and 73%, a false positive rate of 7% and 18%, and a post-test probability of 59% and 68% for boys and girls, respectively. Conclusion: Based on these findings, it can be concluded that the stages of CVM are of limited use for predicting the attainment of the legal age threshold of 14 years. Future studies should investigate whether combinations of skeletal and dental methods could achieve better accuracy and post-test probability.

• The Korean Journal of Mycology
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• v.28 no.2
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• pp.88-92
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• 2000

Substrate improvement, maturation period and method of pinheading promotion were investigated to establish the culture method of Lyopyllum ulmarium which could obtained high yield in the short culture period. Rice bran+wheat bran (10%+10%) combination was selected from various additives, which showed vigorous growth of fruit body and high yield (133.8 g/850 cc). Oyster shells powder substance increased yield to 155.5 g per 850 cc capacity bottle. The suitable method for pinheading promotion was to stand the bottle reversely. The number of fruit bodies per 850 cc capacity bottle in this method was 27.2 stipes and bunch formation was good. When the maturation period of mycelium culture was 15 days to 30 days, pinheading period was 10 days. But when the maturing mycelium was 30 to 45 days, yield per 850 cc bottle was 148.2 g.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.5
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• pp.323-331
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• 2007

Barren ground is an abnormal phenomenon in coastal ecosystems where seaweeds are destroyed and largely replaced by coralline algae containing calcium carbonate components. To restore the seaweed forest, we attempted reconstruction in an area of Samcheok, Korea, where barrenness is extensive. We developed two methods of seaforest construction underwater longline and seed transplantation for the brown seaweed Laminaria japonica, a fast-growing edible seaweed. The blade length of L. japonica attached to an underwater long line was $93.9{\pm}38.2cm$ and blade weight $7.6{\pm}2.1g$ in February 2004. Seaweed size declined after August 2004. A Similar pattern was observed using the transplantation method with maxima of $179.3{\pm}40.3cm\;and\;14.9{\pm}3.2g$ for blade length and weight, respectively in July 2004. The transplanted seaweeds matured in October as did a wild population. These results indicate that transplanted seaweed acclimate to new environments.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.371-378
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• 1992

The ecdysteroid titers of representive developmental stages of the blackblow fly, Phormia regina, were determined by radioimmunoassay and the effect of ecdysteroid on the oocyte maturation was investigated. Prior to every molts ecdysteroid levels began to increase sharply, suggesting ecdysteroid was the major component for egg-larval, larval-larval, and larval-pupal transformation. A difference in the levels of ecdysteroid between male and female was ob¬served during adult life span. Following the protein meal, ecdysteroid in the females increased rapidly to a maximum at 96 hr of age when terminal oocyte fully matured. Effect of ecdysteroid on oocyte development was determined for control and ecdysone-treated female flies after the liver-feeding. The growth of oocyte in the flies treated by $\mu$g of ecdysone, along with the control flies, was not facilitated. When the flies treated by 5 $\mu$g of ecdysone, however, duration of oocyte maturation was shorter than those of other two groups. This can be suggested that oocyte development in P. regina is due to the critical level of ecdysone.