• Journal of Embryo Transfer
• /
• v.32 no.1
• /
• pp.1-8
• /
• 2017

Cryopreservation of germ cells from genetically proven animals could be a source of restoration tools from the risk of extinction or disappearance of wanted characteristics. Using frozen semen, the genetic gains of Korean native cattle have been increased greatly for 70 years. The preservation of genetic resources as a form of frozen semen straw has limited availability due to the numbers. To circumvent this weakness of frozen semen, we tested two re-freezing methods with different initial thawing temperatures using frozen Korean proven semen and rare breed semen from albino, black and chikso breeders. It has been known that human sperm could resist to cryo-damages by repeated freeze-thaw cycles, but not for Korean proven bulls number (KPN) or for rare breeds. Total 7 frozen semem from brindled(2), black(1), Korean Albino(2) and KPN(1) bulls were used for our research. After thawing straws under $5^{\circ}C/2min$ or $37^{\circ}C/40sec$ with low temperature water bath and thermo jug, spermatozoa were re-diluted with triladyl diluents after first thawing and re-frozen. Sperm motilities were compared between animals and treated groups after re-thawing. Mean values of motility and viability of refrozen/thawed sperm for expansion of the number of straws were significantly higher in $5^{\circ}C$ than in $37^{\circ}C$ (P < 0.05). However, the activity of viable sperm thawed at $5^{\circ}C$ was significantly decreased before refreezing. It is estimated that re-freezing of frozen semen from rare Korean native cattle is possible with resistant properties of survived spermatozoa.

• Journal of the Korean Society of International Agriculture
• /
• v.23 no.5
• /
• pp.546-551
• /
• 2011

Chrysanthemums, often called mums or chrysanths, belong to the genus Chrysanthemum, which includes about 30 species of perennial flowering plants in the family Asteraceae. We extracted DNA from Dendranthema grandiflorum ('Smileball') to construct a simple sequence repeat (SSR)-enriched library, using a modified biotin-streptavidin capture method. GS FLX (Genome Sequencer FLX System which provides the flexibility to perform the broad range of applications) sequencing (at the 1/8 run specification) resulted in 18.83 mega base pairs (Mbp) with an average read length of 280.06 bp. Sequence analyses of all SSR-containing clones revealed a predominance of di-nucleotide motifs (16,375, 61.5%) followed by tri-nucleotide motifs (6,616, 24.8%), tetra-nucleotide motifs (1,674, 6.3%), penta-nucleotide motifs (1,283, 4.8%), and hexa-nucleotide motifs (693, 2.6%). Among the di-nucleotide motifs, the AC/CA class was the most frequently identified (93.5% of all di-nucleotide types), followed by the GA/AG class (6.1%), the AT/TA class (0.4%), and the CG/GC class (0.03%). When we analyzed the distribution of different repeat motifs and their respective numbers of repeats, regardless of the motif class, of 100 SSR markers, we found a higher number of di-nucleotide motifs with 70 to 80 repeats; we also found two di-nucleotide motifs with 83 and 89 repeats, respectively, but their product lengths were within optimum size (297 and 300 bp). In future work, we will screen for polymorphisms of possible primer pairs. The results will provide a useful tool for assessing molecular diversity and investigating the population structure among and within Chrysanthemum species.

• Korean Journal of Poultry Science
• /
• v.35 no.2
• /
• pp.163-169
• /
• 2008

A total of 17 polymorphic microsatellite markers on chromosome 1 were used for allelic association tests with phenotypic traits in Korean native chicken. Chi-square tests were performed to compare the frequencies of individual alleles between the high and the low trait groups. The frequency of allele 123 of MCW0160 showed a significant difference between the high and the low groups in the trait of egg weight (EW). Three markers, namely ADL0234, UMA1.125 and ADL0101, were found to show significant differences in allelic distribution for the trait of the first lay day (FLD). UMA1.117, ADL0020, UMA 1.019, LMA1 and ADL0238 were found to show significant differences in allelic distribution for the trait of body weight (BW). ADL0101 and ADL0238 were found to show significant differences in allelic distribution for the trait of number of egg production(EP). In this study, we identified the QTL for economic traits at around 94 (MCW0160), 151 (ADL0234), 170 (UMA1.125), 225 (UMA1.117), 285 (ADL0020), 387 (UMA1.019), 418 (LMA1), 500 (ADL0101) and 520 (ADL0238) cM on chromosome 1 in Korean native chicken. The results provided a useful guideline for identification of positional candidate gene and marker-assisted selection for economic traits in Korean native chicken.

• Korean Journal of Plant Taxonomy
• /
• v.46 no.2
• /
• pp.256-266
• /
• 2016

A total of 13,000 individuals of Dendrobium moniliforme (L.) Sw. artificially propagated in laboratories and greenhouses were restored in their natural habitat of Bogildo Island, Wandogun, in the southern part of Korea in June of 2013. The growing conditions of the individuals were monitored for two years. The parental individuals for the restoration were obtained from a wild population in southern Korea, from which seeds were produced via artificial crossings. These seeds were germinated and cultivated in growing media and two-year-old plants were then grown in greenhouse beds. The genetic diversity among the propagated individuals was confirmed by examining DNA sequences of five regions of the chloroplast genome and the nuclear ITS region. The diversity values were as high as the average values of natural populations. All propagated individuals were transplanted into two different sites on Bogildo by research teams with local residents and national park rangers. After restoration, we counted and measured the surviving individuals, vegetative propagated stems, and growth rates in June of both 2014 and 2015. There was no human interference, and 97% of the individuals survived. The number of propagules increased by 227% in two years. In contrast, the average length of the stems decreased during the period. In addition, different survival and propagation rates were recorded depending on the host plants and the restored sites. The shaded sides of rock cliffs and the bark of Quercus salicina showed the best propagation rates, followed by the bark of Camellia japonica. A few individuals of D. moniliforme successfully flowered, pollinated, and fruited after restoration. Overall, our monitoring data over two years indicate that the restored individuals were well adapted and vigorously propagated at the restored sites. In order to prevent human disturbance of the restored sites, a CCTV monitoring system powered by a solar panel was installed after the restoration. In addition, a human surveillance system is operated by national park rangers with local residents.

• Biomedical Science Letters
• /
• v.4 no.2
• /
• pp.143-151
• /
• 1998

To study the incidence and epidemiological factors of uterine cervical cancer in medical underserved area females, the questionnaire survey and Pap. smear for uterine cervical cancer was done on total 330 women who lived in Ullungdo from 5th to 12th August, 1998. The results were summarized as follows： The age distribution of subjects was 50s (24.5%), 60s (24.5%) and their educational level was “no schooling” (14.2%) and “elementary school” (42.7%). The first coital age of subjects was 19∼21yrs (30.0%), 16∼18yrs (13.9%) and the first pregnancy age was 22∼24yrs (36.7%) and 19∼21yrs (30.0%). The frequency of total pregnancy of subjects was over 5 times (52.1%). The frequency of total delivery was “3∼4 times” (35.5％) and “5∼6 times” (15.2％). 68.8% of subjects had experience of abortion and 80.0% of their husband were on the phimosis. 172 (52.1%) subjects had gynecological symptoms, their symptoms were leukorrhea (48.3%), pruritus (21.5%) and leukorrhea with pruritus (20.3%). 63.9% of total subjects have been received Pap. smear and the frequency of their Pap. smear was “only 1 time” (44.1 ％), “irregularly” (30.3%) and the reason of respondents who have not been received Pap. smea. was “no specific symptom” (51.3%). Among the 330 women screened there were negative (45.8%), inflammation (47.3%), trichomoniasis and candidiasis (1.8%), atypical cells (4.5%) and dysplasia (0.6%).

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.64 no.4
• /
• pp.353-365
• /
• 2019

A near-infrared reflectance spectroscopy (NIRS) prediction model was set to establish a rapid analysis system of wheat germplasm and provide statistical information on the characteristics of protein contents. The variability index value (VIV) of calibration resources was 0.80, the average protein content was 13.2%, and the content range was from 7.0% to 13.2%. After measuring the near-infrared spectra of calibration resources, the NIRS prediction model was developed through a regression analysis between protein content and spectra data, and then optimized by excluding outliers. The standard error of calibration, R², and the slope of the optimized model were 0.132, 0.997, and 1.000 respectively, and those of external validation results were 0.994, 0.191, and 1.013, respectively. Based on these results, a developed NIRS model could be applied to the rapid analysis of protein in wheat. The distribution of NIRS protein content of 6,794 resources were analyzed using a normal distribution analysis. The VIV was 0.79, the average protein was 12.1%, and the content range of resources accounting for 42.1% and 68% of the total accessions were 10-13% and 9.5-14.6%, respectively. The composition of total resources was classified into breeding line (3,128), landrace (2,705), and variety (961). The VIV in breeding line was 0.80, the protein average was 11.8%, and the contents of 68% of total resources ranged from 9.2% to 14.5%. The VIV in landrace was 0.76, the protein average was 12.1%, and the content range of resources of 68% of total accessions was 9.8-14.4%. The VIV in variety was 0.80, the protein average was 12.8%, and the accessions representing 68% of total resources ranged from 10.2% to 15.4%. These results should be helpful to the related experts of wheat breeding.

• Korean Journal of Ichthyology
• /
• v.19 no.4
• /
• pp.274-285
• /
• 2007

The subfamily Chrominae of damselfishes (Teleostei: Pomacentridae) includes the genus Chromis and Dascyllus. They are found throughout the tropical oceans and form a major component of coral reef communities. There are 5 species of the Chrominae currently recognized in Korea. This study was conducted to infer phylogenetic position of two Korean Chromis species and one Dascyllus species within general category of their each genus in worldwide level. This study also includes one species of Japanese Dascyllus. In the phylogenetic analysis, the Japanese D. aruanus grouped with D. aruanus previously reported from French Polynesia. Korean Chromis fumea grouped with Australian C. nitida and the p-distance value between the two species is relatively very low (0.047). Korean C. notatus grouped together with C. flavomaculata (New Caledonia). In the sequence analysis of some Korean and Japanese damselfishes, there was no sequence variation between D. melanurus (Jeju, Korea) and D. melanurus (Indo-Pacific), but the sequences of the two populations were different in only one nucleotide sites from that of D. melanurus in Indonesian Archipelago. The sequences of Dascyllus aruanus (Japan) were different in two nucleotide sites from it in French Polynesia. There were high difference between the sequences of two Korean species, Chromis fumea and Korean C. notatus. The variations among mitochondrial cytochrome b sequences indicate that the gene sequence could be used as DNA barcode for identification of local populations of D. aruaus and D. melanurus as well as species level.

• Korean Journal of Microbiology
• /
• v.34 no.3
• /
• pp.108-114
• /
• 1998

Salmonella Pathgenicity Island 2 plays an important role in Salmonella pathogenicity, especially invasion into host cell. We have investigated the effect of various environmental factors, such as oxygen level, osmolarity, pH, carbon starvation and glycerol addition on the expression of SPI2. For this research, we constructed the reporter plasmids, in which the promoter-less lac operons are fused with the regulatory regions (including promoter) of ssaJ and ssaK, major genes in SPI2. The study using the reporters showed that low oxygen, low osmolarity, or weak alkali conditions increased the expression levels of ssaJ and ssaK and when these three conditions exist simultaneously, the expression levels of ssaJ and ssaK are the highest. However carbon starvation and glycerol addition did not affect the expression of ssaJ and ssaK. These environmental effects on the expression levels of ssaJ and ssaK are the same in three Salmonella typhimurium wild types, LT2, UK1, and SL1344. In addition, we confirmed that the mutation in hilA, a regulatory gene encoding a transcriptional activator of SPI1, had no effect on the expression of ssaJ and ssaK. Thus, these results strongly suggest that the expressions of SPI2 and SPI1 are regulated by different control systems.

• Journal of The Korean Association For Science Education
• /
• v.30 no.8
• /
• pp.933-952
• /
• 2010

This study aims to characterize debate on a socio-scientific issue in the Internet and to provide implications from a postmodernist perspective. This study concentrates on disentanglement of the complex relationship among society, economy, politics and science in an issue and characterization of the given text centering on its originality, the relationship between writer and reader, and the purpose of utterance. Sixty-six most read articles on a web message board were chosen and analyzed as a typical case of a socio-scientific issue in the internet. In them, five scientific disputes were identified: the cause of mad cow disease (MCD), specified risk material and the incubation period, the cause of new variant Creutzfeld-Jakob disease (vCJD), vulnerability of vCJD and the relation of Alzheimer and vCJD in American patients. Each argument is intertwined with social, economic and political problems such as its impact on the domestic beef market, feeding environment of imported cattle and the retaliation against denial of importation. With regard to originality, it is found that the originality of an author is weakened but communal through repetitive quotation of 'Peom', cutting and pasting, and engagement of readers with their comments. Furthermore, in order to close the gap between writer and reader, identity and personal narrative of the writers are often introduced into their writing. In terms of purpose of utterance, these are intended to deliver one's feelings or facilitate human behavior rather than inform through verification of a principle.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.46 no.3
• /
• pp.92-102
• /
• 2018

The purpose of this study is to investigate if subjective well-being could be improved by visiting urban forests near residential areas. Because visiting an urban forest is not an intense positive experience, this research is focused on frequency of affective experience rather than intensity. The independent variables are number of visits and length of stay. The dependent variables are positive affect, negative affect, and life satisfaction. A polling agency was employed to select 600 respondents by quota sampling, and data was collected by online survey. The results of ANOVA showed that there was no interaction between the number of visits and length of stay. Regardless of the number of visits, the subjective well-being of visitors of urban forests was enhanced: (a) positive affect of respondents who had visited in the past 2 weeks was increased while negative affect was decreased, and (b) life satisfaction for those who had visited at least 1 time per month was enhanced among usual visitors. The stay of length, however, had little effect on the increase or decrease of these three variables. The results of this study support the existing theory that one could reset their genetically determined happiness set point to a higher level by participating in intentional activities such as visiting urban forests that offer ways to achieve long-lasting changes in well-being. This means that it would be a valuable government investment to construct and maintain urban forests for improving citizens' welfare. A few comments were suggested regarding data collection and inclusion of influencing variables to make future subjective well-being studies more reliable.