• Korean Journal of Ecology and Environment
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• v.49 no.1
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• pp.11-21
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• 2016

Cymbidium kanran Makino is being threatened in its own habitats due illegal collecting and habitat changes by vegetation growth along historical landuse change. In this study, we established habitat restoration model for conservation of C. kanran based on ecological diagnosis. Through exploration to Jeju Island in 2014 and 2015, we identified 27 unknown habitats of C. kanran and in there, abiotic variables and vegetation structure and composition were quantified. Altitudinal distribution of C. kanran was between 200 m~700 m a.s.l. and compared to distribution in 2004, Area of Occupation (AOO) decreased at 82%. Specific habitat affinity was not observed by evenly found in mountain slope and valley and summergreen and evergreen broadleaved forests, but likely more abundant in valley habitats with higher soil and ambient moisture. Total of 96 individual of C. kanran was observed with an average density of $942.6individuals\;ha^{-1}$. The plants showed relatively short leaf length (average=$10.7cm{\pm}1.1cm$) and small number of pseudo bulbs ($1.2{\pm}0.2$). Flowering and fruiting individuals were not observed in field. C. kanran was classified into endangered plant species as CR (Critically Endangered) category by IUCN criteria. Phenotypic plasticity of C. kanran was likely support to sustain in more shaded habitat environment and recent habatat changes to closed canopy and low light availability may exhibit negatively effects to C. kanran's life history. Restoring C. kanran habitat should create open environment as grassland and low woody species density.

• Journal of the Korean Data and Information Science Society
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• v.26 no.4
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• pp.915-921
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• 2015

This experiment was conducted to estimate the heritability and coheritablity of daily milk yield, acetone and ${\beta}$-hydroxybutyrate (BHBA) concentrations in raw milk. The average concentrations of acetone and BHBA were $135.54{\pm}96.29{\mu}mol$ and $61.08{\pm}66.76{\mu}mol$, respectively, and the differences between high group and low group cows were highly significant (p <0.01). The estimates of heritability of daily milk yield, acetone and BHBA concentrations were in the range of 0.18~0.21, 0.11~0.13 and 0.01~0.02, respectively. The estimate of heritability of $Log_e$acetone did not change much, while that of $Log_eBHBA$ increased to 0.03~0.04. The estimates of phenotypic and genetic correlation coefficients between acetone and BHBA were 0.44 and 0.48, respectively. In low milk yield group, the coheritability estimates of BHBA and $Log_eBHBA$ when selection was for daily milk yield were 0.26 and 0.32, respectively. These were higher than the coheritability estimate of acetone when selection was for daily milk yield. The same trend was noted in the coherihability estimates from the whole records using both high and low milk yield groups together. BHBA concentration seemed to be more effectively responding than acetone concentration when selection was for daily milk yield.

• Development and Reproduction
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• v.12 no.2
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• pp.117-124
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• 2008

The efficient strategies to cope with unpredictable and/or harmful environmental changes have been developed by every organism in order to ensure its survival and continuity of it's own species. As a results, all living things on earth maintain dynamically internal stability via a process termed 'homeostasis' among physiological parameters despite of external environment changes. Stress is an emotional and physical response to threat homeostasis. Stress may have not only transient but rather permanent effect on the organism; recent evidence clearly show that prenatal stress could organize or imprint permanently physiological systems without any change in genetic codes, a process known as 'epigenetic programming'. In this review, a series of reproduction-associated events occurred in prenatally stressed male rats such as alteration in the structure of sexually dimorphic brain regions, modification of neurotransmitter metabolism, changes in reproductive endocrine status, and finally, disorders of sexual behavior will be introduced. The fetal brain is highly sensitive to prenatal programming and glucocorticoids in particular have powerful brain-programming properties. The chronic hyperactivation of fetal brain by maternal stress-induced glucocorticoid input will provide new program via increasing the neuroplasticities. This 'increased neuroplasticities' will be the basis for the 'increased phenotypic plasticities' rendering the organism's better adaptation to environmental challenges. In conclusion, organism who experienced 'harsh' environment in his fetal life seems to give up a certain portion of reproductive competence to make good chance of survival in his future life by epigenetic (re)programming.

• Microbiology and Biotechnology Letters
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• v.33 no.3
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• pp.169-177
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• 2005

This study focuses on investigating roles of microorganisms in decontamination of reed rhizosphere in Sunchon Bay, Korea, which is considered one of the marsh and mud environment severely affected by human activities such as agriculture and fisheries. In general, the bay is known to play the role of the buffering zone to reduce the sudden impact or change by environmental stresses. In our initial efforts to elucidate the microbial functions in decontamination process in reed rhizosphere, pure bacteria capable of degrading aromatic hydrocarbons were isolated from reed (Phragmites communis) rhizosphere of Sunchon bay by enrichment culture using either benzene, toluene, ethylbenzene, or xylene (BTEX) as a sole source of carbon and energy. Measurement of the rates of BTEX degradation and cell growth during the incubation in BTEX media under several temperature conditions demonstrated maximized degradation of BTEX at $37^{\circ}C$ in both strains. Both strains were also resistant to all the heavy metals and antibiotics tested in this study, as well as they grew well at $42^{\circ}C$. Identification of the isolates based on 16S rRNA gene sequences, and a variety of phenotypic and morphologic properties revealed that the two strains capable of BTEX catabolism were among Microbacterium sp., and Rhodococcus sp. with over $95{\%}$ confidence, designated Microbacterium sp. EMB-1 and Rhodococcus sp. EMB-2, respectively This result suggested that in the rhizosphere of reed, one of major salt marsh plants they might play an important roles in decontamination process of reed rhizosphere contaminated with petroleum such as BTEX.

• The Plant Pathology Journal
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• v.26 no.4
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• pp.313-320
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• 2010

Genetic instability of the rice blast fungus Magnaporthe oryzae has been suggested as a major factor underlying the rapid breakdown of host resistance in the field. However, little information is available on the mechanism of genetic instability. In this study, we assessed the stability of repetitive DNA elements and several key phenotypic traits important for pathogenesis after serially transferring two isolates though rice plants and an artificial medium. Using isolate 70-15, we obtained a total of 176 single-spore isolates from 10 successive rounds of culturing on artificial medium. Another 20 isolates were obtained from germ tubes formed at the basal and apical cells of 10 three-celled conidia. Additionally, 60 isolates were obtained from isolate KJ201 after serial transfers through rice plants and an artificial medium. No apparent differences in phenotypes, including mycelial growth, conidial morphologies, conidiation, conidial germination, appressorium formation, and virulence, or in DNA fingerprints using MGR586, MAGGY, Pot2, LINE, MG-SINE and PWL2 as probes were observed among isolates from the same parent isolate. Southern hybridization and sequence analysis of two avirulence genes, AVR-Pita1 and AVR-Pikm, showed that both genes were also maintained stably during 10 successive generations on medium and plants. However, one reversible loss of restriction fragments was found in the telomere-linked helicase gene (TLH1) family, suggesting some telomere regions may be more unstable than the rest of the genome. Taken together, our results suggest that phenotype and genotype of M. oryzae isolates do not noticeably change, at least up to 10 successive generations on a cultural medium and in host plants.

• Korean Journal of Microbiology
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• v.47 no.4
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• pp.295-301
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• 2011

Aquaporin is a water channel protein, which is classified as Major Intrinsic Protein (MIP), found in almost all organisms from bacteria to human. To date, more than 200 members of this family were identified. There are two major categories of MIP channels, orthodox aquaporins and aquaglyceroporins, which facilitate the diffusion across biological membranes of water or glycerol and other uncharged compounds, respectively. The full genome sequencing of various fungal species revealed 3 to 5 aquaporins in their genome. Although some functions of aquaporins found in yeast were characterized, however, no functional characteristics were studied so far in filamentous fungi, including Aspergillus sp. In this study, one orthodox aquaporin homolog gene, aqpA, and four aquaglyceroporin homologs, aqpB-E, in a model filamentous fungus Aspergillus nidulans were identified and the function of the aqpA gene was characterized. Knock-out of the aqpA gene didn't show any obvious phenotypic change under the osmotic stress, indicating that the function of the gene does not involved in the osmotic stress response or the function could be redundant. However, the mutant showed antifungal susceptibility resistance phenotype, suggesting that the function of the aqpA gene could be involved in sensing the antifungal substances rather than the osmotic stress response.

• Korean Journal of Poultry Science
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• v.8 no.1
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• pp.1-5
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• 1981

In trying to predict the effect of genetics on the broiler in the year 2000, this is a relatively short period of time as far as broiler genetics in concerned. Modern broiler genetics started around 1945 and tremendous gains when made in past 35 years. Futher improvements on broiler will depend on the evolution and revolution: 1. Evolution: (1) Growth rate has been made 4-5% per year. (2) Feed conversion has improved approximately 1% per year. (3) Abdominal fat is becoming a major complaint in broiler. (4) Because of the changing life-style, broiler meat sales in the future will be more and more in cut-up form. (5) Breeding for stress resistance and selection for docile temperament can be important in order to funker improve fled efficiency. (6) In female parent stock, reproduction characteristics are in many can negatively correlated with the desired broiler traits. (7) Egg production and hatchability in moot commercial parent nod m at a fairly high level. (8) In male parent stock, the heavier and mon super-meat-type male lines are desired to Product better broilers. 2. Revolution: Trying to forecast revolutionary change in broiler genetics is highly speculative, as sudden change are aften unpredictable. (1) Species hybridization, such as a turkey-chicken cross (2) Biochemical tools, such as blood typing. (3) Mutation breeding by radiation or chemical mutagentia. (4) Broiler breeding would be to change the phenotypic appearance by single gene, such as naked, wingless. (5) Changes in production techniques. such as growing in cage or growing in filtered air positive pressure houses.

• Applied Microscopy
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• v.35 no.3
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• pp.165-176
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• 2005

Studies on molecular plasticity of Bermann glia (BG) after harmaline-induced Purkinje cell (PC) degeneration in the rat cerebellum. The intimate structural relationship between BG and PC, evidenced by the sheathing of the PC dendrites by veil-like process from the BG has been suggestive of the close functional relationship between these two cell types. However, little is known about metabolic couplings between these cells. This study designed to investigate molecular plasticity of BG in the rat cerebellum in which PCs were chemically ablated by harmaline treatment. Immunohistochemical examination reveals that harmaline induced PC degeneration causes a marked glial reaction in the cerebellum with activated BG and microglia aligned in parasagittal stripes within the vermis. In these strips, activated BG were associated with upregulaion of metallotheionein, while GLAST and was down regulated, as compared with nearby intact area where both BG are in contact with PCs. The data from this study demonstrate that BG can change their phenotypic expression when BG loose their contact with PCs. It is conceivable that activated BG may upregulate structural proteins, metallothionein expression to use for their proliferation and hypertrophy; metallothionein expression to cope with oxidative stress induced by PC degeneration and microglial activation. On the contrary, BG may down regulated expression of GLAST because sustained loss of contact with PCs would eliminate the necessity for the cellular machinery involved glutamate metabolism. In conclusion, BG might respond man to death of PCs by undergoing a change in metabolic state. It seems possible that signaling molecules released from PCs regulates the phenotype expression of BG. Also ultrastructures in the organelles of normal PC and BG are distinguished by mitochondrial appearance, and distributed vesicles at the synaptic area in the cytoplasm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.3
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• pp.89-98
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• 1965

The experimental studies were intended to clarify the effects of selection, and also aimed at estimating the heritabilities, the genotypic correlations among some agronomic characters, and at calculating the selection index on some selective characters for the selection of desirable lines, under different climatic conditions. Finally practical implications of these studies, especially on the selection index, were discussed. Twenty-two varieties, determinate growing habit type, were selected at random from the 138 soybean varieties cultivated the year before, were grown in a randomized block design with three replicates at Chinju, Korea, under May and June sowing conditions. The method of estimating heritabilities for the eleven agronomic characters-flowering date, maturity date, stem length, branch numbers per plant, stem diameter, plant weight, pod numbers per plant, grain numbers per plant and 100 grain weight, shown in Table 3, was the variance components procedures in a replicated trial for the varieties. The analysis of covariance was used to obtain the genotypic correlations and phenotypic correlations among the eight characters, and the selection indexes for some agronomic characters were calculated by Robinson's method. The results are summarized as follows: Heritabilities : The experiment on the genotype-environment interaction revealed that in almost all of the characters investigated the interaction was too large to be neglected and materially affected the estimates of various genotypic parameters. The variation in heritability due to the change of environments was larger in the characters of low heritability than in those of high heritability. Heritability values of flowering date, fruiting period (days from flowering to maturity), stem length and 100 grain weight were the highest in both environments, those of yield(grain weight) and other characters were showed the lower values(Table 3). These heritability values showed a decreasing trend with the delayed sowing in the experiments. Further, all calculated heritability values were higher than anticipated. This was expected since these values, which were the broad sense heritability, contain the variance due to dominance and epistasisf in addition to the additive genetic variance. Genotypic correlations : Genotypic correlations were slightly higher than the corresponding phenotypic correlations in both environments, but the variation in values due to the change of environment appeared between grain weight and some other characters, especially an increase between grain weight and flowering date, and the total growing period(Table 6). Genotypic correlations between grain weight and other characters indicated that high seed yield was genetically correlated with late flowering, late maturity, and the other five characters namely branch numbers per plant, stem diameter, plant weight, pod numbers per plant and grain numbers per plant, but not with 100 grain weight of soybeans. Pod numbers and grain numbers per plant were more closely correlated with seed yields than with other characters. Selection index : For the comparison and the use of selection indexes in the selection, two kinds of selection indexes were calculated, the former was called selection index A and the later selection index B as shown in Table 7. Selection index A was calculated by the values of grain weight per plant as the character of yield(character Y), but the other, selection index B, was calculated by the values of pod numbers per plant, instead of grain weight per plant, as the character of yield'(character Y'). These results suggest that selection index technique is useful in soybean breeding. In reality, however, as the selection index varies with population and environment, it must be calculated in each population to which selection is applied and in each environment in which the population is located. In spite of the expected usefulness of selection index technique in soybean breeding, unsolved problems such as the expense, time and labor involved in calculating the selection index remain. For these reasons and from these experimental studies, it was recognized that in the breeding of self-fertilized soybean plants the selection for yield should be based on a more simple selection index such as selection index B of these experiments rather than on the complex selection index such as selection index A. Furthermore, it was realized that the selection index for the selection should be calculated on the basis of the data of some 3-4 agronomic characters-maturity date(X$_1$), branch numbers per plant(X$_2$), stem diameter(X$_3$) and pod numbers per plant etc. It must be noted that it should be successful in selection to select for maturity date(X$_1$) which has high heritability, and the selection index should be calculated easily on the basis of the data of branch numbers per plant(X$_2$), stem diameter(X$_3$) and pod numbers per plant, directly after the harvest before drying and threshing. These characters should be very useful agronomic characters in the selection of Korean soybeans, determinate growing habit type, as they could be measured or counted easily thus saving time and expense in the duration from harvest to drying and threshing, and are affected more in soybean yields than the other agronomic characters.

• Journal of Life Science
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• v.30 no.8
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• pp.701-707
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• 2020

Gene editing technology using the clustered regularly interspaced short palindromic repeat (CRISPR) and the CRISPR associated protein (Cas)9 has been highly anticipated in developing breeding techniques. In this study, we discuss gene scissors as a tool for silkworm molecular breeding through analysis of Bombyx mori Kynurenine 3-Monooxygenase (BmKMO) gene editing using the CRISPR/Cas9 system and analysis of generational transmission through mutagenesis and selective crossing. The nucleotide sequence of the BmKMO gene was analyzed, and three guide RNAs (gRNAs) were prepared. Each synthesized gRNA was combined with Cas9 protein and then analyzed by T7 endonuclease I after introduction into the BM-N silkworm cell line. To edit the silkworm gene, K1P gRNA and Cas9 complexes were subsequently microinjected into the silkworm embryos; the hatching rate was 18% and the incidence of mutation was 60%. The gene mutation was verified in the heterozygous G0 generation, but no phenotypic change was observed. In homozygotes generated by self-crossing, a mutant phenotype was observed. These results suggest that silkworm molecular breeding using the CRISPR/Cas9 system is possible and could be an effective way of shortening the time required.