• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.1.1-1.13
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• 2016

Objectives To investigate the accuracy and scientific validity of the current very low risk factor for hereditary diseases in humans following exposures to ionizing radiation adopted by the United Nations Scientific Committee on the Effects of Atomic Radiation and the International Commission on Radiological Protection. The value is based on experiments on mice due to reportedly absent effects in the Japanese atomic bomb (A-bomb) survivors. Methods To review the published evidence for heritable effects after ionising radiation exposures particularly, but not restricted to, populations exposed to contamination from the Chernobyl accident and from atmospheric nuclear test fallout. To make a compilation of findings about early deaths, congenital malformations, Down's syndrome, cancer and other genetic effects observed in humans after the exposure of the parents. To also examine more closely the evidence from the Japanese A-bomb epidemiology and discuss its scientific validity. Results Nearly all types of hereditary defects were found at doses as low as one to 10 mSv. We discuss the clash between the current risk model and these observations on the basis of biological mechanism and assumptions about linear relationships between dose and effect in neonatal and foetal epidemiology. The evidence supports a dose response relationship which is non-linear and is either biphasic or supralinear (hogs-back) and largely either saturates or falls above 10 mSv. Conclusions We conclude that the current risk model for heritable effects of radiation is unsafe. The dose response relationship is non-linear with the greatest effects at the lowest doses. Using Chernobyl data we derive an excess relative risk for all malformations of 1.0 per 10 mSv cumulative dose. The safety of the Japanese A-bomb epidemiology is argued to be both scientifically and philosophically questionable owing to errors in the choice of control groups, omission of internal exposure effects and assumptions about linear dose response.

• Journal of Crop Science and Biotechnology
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• 제11권2호
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• pp.91-100
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• 2008

Melting curve analysis of fluorescently labeled DNA fragments is used extensively for genotyping single nucleotide polymorphism(SNP). Here, we evaluated a SNP genotyping method by melting curve analysis with the two probe chemistries in a 384-well plate format on a Roche LightCycler 480. The HybProbe chemistry is based on the fluorescence resonance energy transfer(FRET) and the SimpleProbe chemistry uses a terminal self-quenching fluorophore. We evaluated FRET HybProbes and SimpleProbes for two SNP sites closely linked to two quantitative trait loci(QTL) for southern root-knot nematode resistance. These probes were used to genotype the two parents and 94 $F_2$ plants from the cross of PI 96354$\times$Bossier. The SNP genotypes of all samples determined by the LightCycler software agreed with previously determined SSR genotypes and the SNP genotypes determined on a Luminex 100 flow cytometry instrument. Multiplexed HybProbes for the two SNPs showed a 98.4% success rate and 100% concordance between repeats two of the same 96 DNA samples. Also, we developed a HybProbe assay for the Rcs3 gene conditioning broad resistance to the frogeye leaf spot(FLS) disease. The LightCycler 480 provides rapid PCR on 384-well plate and allows simultaneous amplification and analysis in approximately 2 hours without any additional steps after amplification. This allowed for a reduction of the potential contamination of PCR products, simplicity, and enablement of a streamlined workflow. The melting curve analysis on the LightCycler 480 provided high-throughput and rapid SNP genotyping and appears highly effective for marker-assisted selection in soybean.

• Clinical and Experimental Reproductive Medicine
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• 제37권4호
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• pp.267-291
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• 2010

최근 동결기술이 발달하면서 다양한 목적에 따라 초기 발생단계, 특히 수정 전후의 난자나 수정란의 생명을 연장하는 것이 가능해졌다. 이러한 난자나 수정란의 보존기술은 인간의 수정능력을 배가시키거나 임신조절에서 응용되고 있으며, 동물에서는 우수한 유전자원의 보존과 운영, 저렴한 국제간 운송수단, 그리고 생식보조기술과 유전공학 등의 연구에 필요한 생식세포의 공급하는 데서도 중요하게 활용되고 있다. 최근 개발된 완만동결과 유리화 동결방법은 난자와 수정란을 장기간 동결하여 보존하는데 활용하는 주요 기술이다. 이러한 방법들은 각각 장점과 단점을 가지고 있지만, 상당한 수준의 효율성이 입증되어 실용화되어 있는 실정이다. 무엇보다도 유리화 방법은 완만동결 방법보다 13년이나 늦게 개발되었으나 보다 우수한 기술로 인정을 받고 있다. 비록 유리화 동결은 아직 대한 상반된 의견과 오염문제가 있지만 인간과 동물의 생식보조기술로 활용되는 빈도가 점차 많아지고 있는 실정이다. 따라서 본 원고에서는 먼저 난자와 수정란의 동결보존에 대한 기초적인 기술에 대해서 고찰한 다음, 유리화 동결에 관 한 최근의 연구동향에 대해서 종합적으로 검토하고자 한다.

• Journal of Microbiology and Biotechnology
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• 제29권10호
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• pp.1522-1542
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• 2019

To adapt to environmental changes and to maintain cellular homeostasis, microorganisms adjust the intracellular concentrations of biochemical compounds, including metal ions; these are essential for the catalytic function of many enzymes in cells, but excessive amounts of essential metals and heavy metals cause cellular damage. Metal-responsive transcriptional regulators play pivotal roles in metal uptake, pumping out, sequestration, and oxidation or reduction to a less toxic status via regulating the expression of the detoxification-related genes. The sensory and regulatory functions of the metalloregulators have made them as attractive biological parts for synthetic biology, and the exceptional sensitivity and selectivity of metalloregulators toward metal ions have been used in heavy metal biosensors to cope with prevalent heavy metal contamination. Due to their importance, substantial efforts have been made to characterize heavy metal-responsive transcriptional regulators and to develop heavy metal-sensing biosensors. In this review, we summarize the biochemical data for the two major metalloregulator families, SmtB/ArsR and MerR, to describe their metal-binding sites, specific chelating chemistry, and conformational changes. Based on our understanding of the regulatory mechanisms, previously developed metal biosensors are examined to point out their limitations, such as high background noise and a lack of well-characterized biological parts. We discuss several strategies to improve the functionality of the metal biosensors, such as reducing the background noise and amplifying the output signal. From the perspective of making heavy metal biosensors, we suggest that the characterization of novel metalloregulators and the fabrication of exquisitely designed genetic circuits will be required.

• Journal of Genetic Medicine
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• 제16권2호
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• pp.76-80
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• 2019

About 15% to 20% of all clinically recognized pregnancies result in spontaneous abortion or miscarriage, and chromosomal anomalies can be identified in up to 50% of first trimester miscarriages. Chromosomal microarray analysis (CMA) is currently considered first-tier testing for detecting fetal chromosomal abnormalities and is supported by the absence of cell culture failure or erroneous results due to cell contamination in pregnancy loss. Triploidy is a lethal chromosome number abnormality characterized by an extra haploid set of chromosomes. Triploidy is one of the most common chromosomal aberrations in first trimester spontaneous abortions. Here, we report two cases of triploidy abortion that were not detected using array comparative genomic hybridization-based CMA. The aim of this report was to remind clinicians of the limitations of chromosomal testing and the misdiagnosis that can result from biased test selection.

• 한국수산과학회지
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• 제47권3호
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• pp.241-246
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• 2014

Viruses in the genus Megalocytivirus have been subdivided into four subgroups. Among these subgroups 2 and 4, represented by the red sea bream iridovirus (RBIV) and the olive flounder iridovirus (FLIV), respectively, are non-exotic. subgroups 1 and 3, represented by the red sea bream iridovirus (RSIV) and the infectious spleen and kidney necrosis virus (ISKNV), respectively, have not been detected in Korea and are known as exotic. Shellfish are filter-feeders, and can thus filter and accumulate Megalocytivirus in their digestive glands, allowing us to track viral contamination in surrounding aquatic environment. In this study, we developed a high-resolution melting (HRM) analysis to differentiate among subgroups of Megalocytivirus accumulated in shellfish, and confirmed the convenience and efficiency of this method. More than two subgroups of Megalocytivirus were found in the digestive gland of a single shellfish. We classified all Megalocytivirus viruses from shellfish in Korea into subgroups 2 and 4, although proportions of subgroups were different among regions. Compared to nucleotide sequencing analysis, HRM analysis is a simple and rapid method for differentiating of Megalocytivirus subgroups.

• 대한수의학회지
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• 제49권4호
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• pp.319-328
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• 2009

This study investigated the epidemiology of Listeria (L.) monocytogenes, a food-borne pathogen. The epidemiology of food-borne pathogens is of great importance for clarifying bacterial origin and preventing bacterial contamination and infection. This work examined 68 L. monocytogenes strains, including 11 reference strains and 57 isolates from imported US beef, domestic meats (beef, pork, chicken meat), raw milk, and milk plants. The random amplified polymorphic DNA (RAPD) techniques were optimized to develop a standard molecular epidemiological analysis of L. monocytogenes. There was great genetic variability among the isolates, which produced 24 and 34 RAPD patterns with primer HLWL85 and HLWL74, respectively. The discriminatory power of the RAPD methods with HLWL85 and HLWL74 primer were very high (DI = 0.957; S ${\geq}$ 80%, S ${\geq}$ 95%). Some RAPD types were specific to origin. A few RAPD types were specific for L. monocytogenes strains belonging to a particular serotype. Using the HLWL85 primer, the strains isolated from milk plants could be distinguished from the other strains. And using the HLWL74 primer, the strains isolated from imported beef (US) could be distinguished completely from the other strains.

• Journal of Plant Biotechnology
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• 제33권4호
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• pp.263-270
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• 2006

Pongamia pinnata Pierre is a tree legume, having potential in production of raw material for biodiesel. A protocol for in wk propagation of this plant was standardized using seedling explants. Growth regulators (GR) including gibberellic acid $(GA_3),\;N^6-benzylaminopurine(BA)$, thidiazuron (TDZ), and Adenine sulphate (Ads) were tested for optimum germination of seeds. Removal of seed coat prior to germination, controlled fungal growth partially but enhanced bacterial growth. Antibiotic cefotaxime was ineffective in controlling bacterial contamination. Seedling derived nodal explants and cotyledon nodes with attached cotyledons were excised and cultured for induction of shoots. Optimum sprouting and multiplication of shoot buds were obtained in MS medium supplemented with $8.88{\mu}M$ BA. These buds differentiated and rooted on medium devoid of GR. Optimum growth of Pongamia seedling was obtained in cotton plugged culture vessels. Reculturing of the cotyledon node explants produced more shoots from the same site. This process of removing shoots and reculturing of cotyledon node was followed for eight passages yielding 4 to 8 shoots in each cycle. The shoots (75%) rooted on half strength MS basal medium supplemented with 0.22% charcoal. All plants survived on transfer to soil. This is the first report on in vitro regeneration of Pongamia pinnata. This report demonstrates the possibility of coupling more than one parameter in single experiment to hasten the process of standardization. The process of cycling the nodal explant repeatedly for production of large number of shoots from single meristem may find application in genetic transformation experiments wherein meristems are used for transformation.

• Fisheries and Aquatic Sciences
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• 제21권3호
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• pp.8.1-8.6
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• 2018

Desmarestia japonica (Phaeophyceae, Desmarestiales) was recently established from the Japanese ligulate Desmarestia and is morphologically similar to D. ligulata. This species has been reported only from Japan. However, the taxonomic reports based on additional regional distributions are needed to clarify this taxonomic entity and its species boundaries. Because Desmarestia species have restricted distributions in Korea, we reexamined herbarium specimens of D. ligulata deposited at the National Institute of Biological Resources (South Korea). To improve the amplification efficiency of the polymerase chain reaction and avoid contamination by the DNA of other organisms, we developed taxon-specific molecular markers suitable for DNA barcoding of Desmarestia species. Nuclear ribosomal small subunit RNA (18S rDNA) and mitochondrial cytochrome c oxidase 1 (cox1) regions were selected as target DNA. As a result, both were successfully isolated from herbarium specimens of D. japonica acquired over 10 years. These molecular markers provide useful genetic information for herbarium specimens for which conventional molecular analysis is challenging.

• Weed & Turfgrass Science
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• 제3권3호
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• pp.221-224
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• 2014

Genetically modified (GM) crops are not permitted to be cultivated in Korea, but can only be imported as food or feed purposes. The import of GM crops has sharply increased in recent years, thus raising concerns with regard to the unintentional escape of these crops during transport and manufacturing as well as the subsequent contamination of local, non-GM plants. Hence, monitoring of GM crops was studied in or outside of grain receiving ports as well as from feed-processing plants in Korea during July 2008. We observed spilled maize grains and established plants primarily in storage facilities that are exposed around the harbors and near transportation routes of the feed-processing areas. Based on the PCR analyses, a total of 17 GM maize plants and 11 seeds were found among the samples. In most cases, the established maize plants found in this study were at the vegetative stage and thus failed to reach the reproductive stage. This study concludes that, in order to prevent a genetic admixture in the local environment for GM crops or seeds, frequent monitoring work and proper action should be taken.