• Journal of Genetic Medicine
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• v.5 no.1
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• pp.7-14
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• 2008

Twenty years have passed since a prenatal screening for Down syndrome and neural tube defect was applied to obstetric field. The Quad test (AFP, hCG, uE3, Inhibin-A) of the second trimester and the combination test (PAPP-A, hCG, NT) of the first trimester became popular now. The recent trend of prenatal screening is to combine these two screening tests together in order to increase a detection rate of Down syndrome. Three types of screening methods are introduced as follows; integrated test, sequential test and contingent test. In addition to combination of each test, an incorporation of characteristic ultrasound findings of Down syndrome is suggested for its risk calculation. The absence of fetal nasal bone would be a very useful marker especially in the first trimester screening test. According to a change of way calculating risk of Down syndrome, obstetrician's role will be more increased not by passive participation, but by active participation using ultrasound in risk calculation.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.155-160
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• 2001

Changes in genetic diversity after seed-tree practice were simulated in test plantation of tulip tree at Sokdal-ri, Banwol-myon, Hwasung-gun, Kyungki Provence. I-SSR markers were analyzed in a total of 305 tulip trees. A total of 89 amplicon variants were observed by PCR with 9 I-SSR primers. Genetic diversity for 305 trees was relatively high (S. I. =0.4532). Individuals originated from the seed orchards in U.S.A. showed the highest level of genetic diversity (0.4530), those from Anyang showed the medium level (0.4152), and those from Cheonbuk showed the lowest (0.3929). Simulation of seed-tree practice accompanied by 2 consecutive thinnings was performed on the basis of morphological characteristics and planted distances of the individual trees, which left 37 trees as candidates for seed-trees. Decreasing rate of genetic diversity within seed sources was greatest for individuals from Cheonbuk (28.3%), moderate for those from Anyang (16.3%), and smallest for those from U.S.A. (8.0%). In spite of little difference in decreasing rate of individuals for the 3 seed sources (87.5~88.2%), large difference in decreasing rate of genetic diversity within seed sources might be due to difference in number of mother trees for the 3 seed sources. For example, whereas individuals originated from the seed orchard in U.S.A., which showed the smallest decreasing rate of genetic diversity, might be originated from relatively large number of mother trees, those from Anyang and Cheonbuk might be originated from relatively small number of mother trees. Although mean of 17.5% of the genetic diversity within seed sources was decreased through 2 consecutive thinnings, a decrease in genetic diversity for the whole individuals (37 trees) was only 6.1%. This observation suggests that the seed-tree practice on the basis of the criteria established in the present study may not result in great reduction in overall genetic diversity of the progenies.

• The Plant Pathology Journal
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• v.31 no.3
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• pp.226-244
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• 2015

Fusarium head blight is one of the most important and most common diseases of winter wheat. In order to better understanding this disease and to assess the correlations between different factors, 30 cultivars of this cereal were evaluated in a two-year period. Fusarium head blight resistance was evaluated and the concentration of trichothecene mycotoxins was analysed. Grain samples originated from plants inoculated with Fusarium culmorum and naturally infected with Fusarium species. The genetic distance between the tested cultivars was determined and data were analysed using multivariate data analysis methods. Genetic dissimilarity of wheat cultivars ranged between 0.06 and 0.78. They were grouped into three distinct groups after cluster analysis of genetic distance. Wheat cultivars differed in resistance to spike and kernel infection and in resistance to spread of Fusarium within a spike (type II). Only B trichothecenes (deoxynivalenol, 3-acetyldeoxynivalenol and nivalenol) produced by F. culmorum in grain samples from inoculated plots were present. In control samples trichothecenes of groups A (H-2 toxin, T-2 toxin, T-2 tetraol, T-2 triol, scirpentriol, diacetoxyscirpenol) and B were detected. On the basis of Fusarium head blight assessment and analysis of trichothecene concentration in the grain relationships between morphological characters, Fusarium head blight resistance and mycotoxins in grain of wheat cultivars were examined. The results were used to create of matrices of distance between cultivars - for trichothecene concentration in inoculated and naturally infected grain as well as for FHB resistance Correlations between genetic distance versus resistance/mycotoxin profiles were calculated using the Mantel test. A highly significant correlation between genetic distance and mycotoxin distance was found for the samples inoculated with Fusarium culmorum. Significant but weak relationships were found between genetic distance matrix and FHB resistance or trichothecene concentration in naturally infected grain matrices.

• Journal of KIISE:Software and Applications
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• v.28 no.9
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• pp.669-680
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• 2001

Genetic Algorithms are optimization algorithm that mimics biological evolution to solve optimization problems. Genetic algorithms provide an alternative to traditional optimization techniques by using directed random searches to locate optimal solutions in complex fitness landscapes. Hybrid genetic algorithm that is combined with local search called learning can sustain the balance between exploration and exploitation. The genetic traits that each individual in the population learns through evolution are transferred back to the next generation, and when this learning is combined with genetic algorithm we can expect the improvement of the search speed. This paper proposes a genetic algorithm based Cellular Learning with accelerated learning capability for function optimization. Proposed Cellular Learning strategy is based on periodic and convergent behaviors in cellular automata, and on the theory of transmitting to offspring the knowledge and experience that organisms acquire in their lifetime. We compared the search efficiency of Cellular Learning strategy with those of Lamarckian and Baldwin Effect in hybrid genetic algorithm. We showed that the local improvement by cellular learning could enhance the global performance higher by evaluating their performance through the experiment of various test bed functions and also showed that proposed learning strategy could find out the better global optima than conventional method.

• Korean Journal of Plant Resources
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• v.23 no.4
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• pp.360-367
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• 2010

The genetic diversity and structure of P. tongkangensis in 5 populations from 3 regions was investigated using 56 markers derived from 6 ISSR primers. Genetic diversity at the species level (P=94.6, SI=0.377, h=0.240) was substantial considering the limited distribution and small size of populations. Genetic differentiation among regions (12%) and among populations (13%) in the region was not clearly evident, which suggested a moderate level of gene flow among adjacent populations. The Mantel test revealed a significant correlation between genetic differentiation (${\Phi}_{ST}$) and geographic distance among populations. This was supported by cluster analysis and principal coordinate analysis (PCoA). The significant difference in marker band frequency at many loci and their fixation in opposite directions in the smallest and most isolated population SC were considered due to genetic drift. Therefore, the genetic diversity of P. tongkangensis could be compromised if the distribution area or the size of the population was further reduced. In particular, small and isolated populations could be at great risk of extinction. Considering this, the unique habitats of P. tongkangensis should be protected and the reduction of population size should be closely monitored. Conservation efforts including the seeding and planting of seedlings should be done carefully based on their genetic and ecological traits. Our data support the argument that establishing an integrated management system for the efficient conservation of P. tongkangensis is critical.

• Journal of agriculture & life science
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• v.44 no.2
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• pp.17-28
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• 2010

This study looked into how much maternal genetic effect influenced on economic traits through estimation of genetic parameter and heritability over swine's economic traits by maternal animal model using GGP farm examination data of total 31,455 swine of Duroc species, Landrace species and Yorkshire species that were born between 2000 and 2008. As a result of significance test over each factor in surveyed all traits, high significance was approved in the effect of breed, gender, the date of swine's birth, the season swine's born, and difference in delivery in every trait (p<0.01). It is considered that it would be possible to get more efficient improvement effect provided correlation between additive genetic effect and maternal genetic effect as well as maternal genetic effect according to breed, traits, and improvement direction are properly considered as negative covariance existed between additive genetic distribution and maternal genetic distribution presumed for traits by each breed and their genetic relation also showed mostly strong negative correlation.

• Korean Journal of Plant Resources
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• v.28 no.2
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• pp.279-289
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• 2015

Genetic diversity and genetic differentiation of thirteen Pinus densiflora populations in South Korea were estimated using nine ESTP (Expressed Sequence Tag Polymorphism) markers. The numbers of allele and the effective allele were 2.2 and 1.8, respectively. The percentage of polymorphic loci (P) was 98.8%. The observed and the expected heterozygosity were 0.391 and 0.402, respectively, and the eleven populations except for Ahngang and Gangneung population were under Hardy-Weinberg equilibrium state. The level of genetic differentiation (Wright’s F_ST = 0.057) was higher than those of isozyme or nSSR markers. We could not find out any relationship between the genetic distance and geographic distribution among populations from cluster analysis. Also, the genetic differentiation between populations was not correlated with the geographic distance (r = 0.017 and P = 0.344 from Mantel test). From the result of F_ST-outlier analysis to identify a locus under selection, six loci were detected at confidence interval of 99% by the frequentist’s method. However, only three loci (sams2+AluⅠ, sams2+RsaⅠ, PtNCS_p14A9+HaeⅢ) were presumed as outliers by Bayesian method. The sams2+AluⅠ and sams2+RsaⅠlocus were originated from the sams2 gene and seemed to be the loci under balancing selection.

• Genes and Genomics
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• v.40 no.11
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• pp.1213-1223
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• 2018

Pelagic larval dispersal habits influence the population genetic structure of marine mollusk organisms via gene flow. The genetic information of the clam Gomphina aequilatera (short larval stage, 10 days) which is ecologically and economically important in the China coast is unknown. To determine the influence of planktonic larval duration on the genetic structure of G. aequilatera. Mitochondrial markers, cytochrome oxidase subunit i (COI) and 12S ribosomal RNA (12S rRNA), were used to investigate the population structure of wild G. aequilatera specimens from four China Sea coastal locations (Zhoushan, Nanji Island, Zhangpu and Beihai). Partial COI (685 bp) and 12S rRNA (350 bp) sequences were determined. High level and significant $F_{ST}$ values were obtained among the different localities, based on either COI ($F_{ST}=0.100-0.444$, P<0.05) or 12S rRNA ($F_{ST}=0.193-0.742$, P<0.05), indicating a high degree of genetic differentiation among the populations. The pairwise $N_m$ between Beihai and Zhoushan for COI was 0.626 and the other four pairwise $N_m$ values were >1, indicating extensive gene flow among them. The 12S rRNA showed the same pattern. AMOVA test results for COI and 12S rRNA indicated major genetic variation within the populations: 77.96% within and 22.04% among the populations for COI, 55.73% within and 44.27% among the populations for 12S rRNA. A median-joining network suggested obvious genetic differentiation between the Zhoushan and Beihai populations. This study revealed the extant population genetic structure of G. aequilatera and showed a strong population structure in a species with a short planktonic larval stage.

• The Korea Journal of Herbology
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• v.25 no.2
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• pp.137-144
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• 2010

Objectives : We investigated genetic toxicity of HMCO5 using the Micronucleus Test in bone marrow cells of mice and Bacterial Reverse Mutation Assay in plate incorporation method according to OECD Guidelines and KFDA Guidelines. Methods : 1. Micronucleus test: The male rats were divided into 5 groups, respectively; G(1), treated with distilled water: G(2), treated with 1250mg/kg HMC05: G(3), treated with 2500mg/kg HMC05, G(4), treated with 5,000mg/kg HMC05; G(5), treated with Cyclophosphamide $H_2O$. Sterilized distilled water and HMC05 were administered for two consecutive days. Cyclophosphamide $H_2O$ was administered once on the day of 2nd administration. 2. Bacterial Reverse Mutation Aassay: Experimental groups were divided into two groups: with S-9mix(+S) or without S-9mix(-S). Each group treated with sterilized distilled water only, HMCO5(62, 185, 556, 1,667, $5,000{\mu}g$/plate) and, positive vehicles(Sodium azide, 2-Aminoanthracene, 4-Nitroquinoline N-oxide, ICR 191), respectively. Results : HMC05 did not show any changes in the number of micronucleated polychromatic erythrocytes(MNPCE) among 200 polychromatic erythrocytes compare to negative control. However, there were significant (p<0.01) increase with CPA in MNPCE. In Bacterial Reverse Mutation Aassay, no significant increases in the number of revertant colonies compared to (삭제) negative control were detected in all concentrations of HMC05. Conclusions : These results indicate that HMC05 did not show any genotoxicity against in Micronucleus test and Bacterial Reverse Mutation Aassay.

• Korean Journal of Poultry Science
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• v.23 no.2
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• pp.99-106
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• 1996

Because of the imminent market opening of livestock and poultry products, Korean poultry industry is faced an influx of contagious diseases from abroad. Due to the increasing trend of intensive and automatic poultry farming, the risks of catching various poultry epidemics are ever more increasing. For the prevention of poultry epidemics, the principles of biosecurity should be observed rather strictly. In addition, regular checking to confirm the presence or absence of latent diseases through serological test, post-mortem examination, and laboratory test, should be carried out routinely. Finally, all kinds of stress factors should be minimized to keep the flock healthy and productive, so that they can achieve their maximum genetic potential.