• Journal of The Korean Society of Inherited Metabolic disease
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• v.13 no.1
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• pp.48-53
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• 2013

Tyrosinemia I (fumarylacetoacetate hydrolase deficiency) is an autosomal recessive inborn error of tyrosine metabolism that produces liver failure in infancy or a more chronic course of liver disease with cirrhosis, often complicated by hepatocellular carcinoma in childhood or early adolescence. We studied a 37-year-old woman with tyrosinemia I whose severe liver disease in infancy and rickets during childhood were resolved with dietary therapy. From 14 years of age, she resumed unrestricted diet with the continued presence of the biochemical features of tyrosinemia, yet maintained normal liver function. In adult years, she accumulated only a small amount of succinylacetone. Despite this evolution to a mild biochemical and clinical phenotype, she eventually developed hepatocellular carcinoma. Her fumarylacetoacetate hydrolase genotype consists of a splice mutation, IVS6-1G>T, and a novel missense mutation, p.Q279R. Studies of resected liver revealed the absence of hydrolytic activity and immunological expression of fumarylacetoacetate hydrolase in tumour. In the non-tumoral areas, however, 53% of normal hydrolytic activity and immunologically present fumarylacetoacetate hydrolase were found. This case demonstrates the high risk of liver cancer in tyrosinemia I even in a seemingly favorable biological environment. In this study of tyrosinemia I, Case 2 with negative succinylacetone accumulation and the recovery of acute liver failure was compared with Case 1. Diet restriction and NTBC treatment are crucial to prevent hepatocellular carcinoma until liver transplant can take place and cure the condition. Further studies are needed to examine cases where liver cancer did not result despite clinical symptoms/signs of tyrosinemia type I.

• Animal Systematics, Evolution and Diversity
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• v.33 no.2
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• pp.140-143
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• 2017

A winged midge species, Parochlus steinenii is one of the most abundant species in Antarctica, which is distributed over a wide area from the South American continent to the South Shetland Islands in Antarctica. It was dispersed into islands in the South Shetland Islands from the South American continent, and it adapted to a variety of environments and settled. This species, therefore, is a good model organism to explain the evolutionary process of Antarctic terrestrial fauna. Nevertheless, there are few genetic studies on this species, which are necessary for understanding the genetic diversity, population structure, etc. Here, we developed and characterized 14 polymorphic microsatellite markers. The number of alleles per locus ranged from 2 to 5. The observed and expected heterozygosities were in the range of 0.024 to 0.561 and 0.024 to 0.535, respectively. Identifying genetic differences between populations, they are suitable markers for researches investigating genetic diversity and population structure of P. steinenii, which provide us with clues to dispersion, evolution and ecology of this species.

• The Korean Journal of Mycology
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• v.27 no.1 s.88
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• pp.27-31
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• 1999

The internal transcribed spacer II regions (ITS II) of the ribosomal DNA gene repeat from Coprinus spp. were amplified using polymerase chain reaction (PCR) and sequenced. Sequences from 11 species including Coprinus comatus, C. atramentarius, C. micaceus, C. lagopus, C. cinereus, C. rhizophorus, C. flocculosus, C. radians, and C. echinosporus were compared. The spacer regions of them were $253{\sim}275$ nucleotide in length and partially contained 5.8S and 25S. The reciprocal homologies of each ITS II sequence among these strains were in the range of $50.6{\sim}100%$. According to the analysis of ITS II sequences, Coprinus spp. were classified into three clusters. Cluster I consisted of Coprinus lagopus, C. cinereus, C. echinosporus, C. rhizophorus, C. niveus, and C. atramentarius. Cluster II comprised C. micaceus, C. flocculosus, C. radians, and C. disseminatus. On the other hand C. comatus is in Cluster III even though this species is belonging to the section Coprinus in morphological aspect. These results suggest that Coprinus comatus, which was considered as a type species of the genus Coprinus in morphological classification, gives a doubt of monophyletic evolution and is assumed to be paraphyletic or polyphyletic.

• Animal Systematics, Evolution and Diversity
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• v.27 no.1
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• pp.47-52
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• 2011

Creeping ctenophores, Coeloplana species, were collected by SCUBA divers throughout the year (November 2006 to June 2010) from the branches and polyp masses of encrusting dendronephthyas at a depth of 20-32m off Munseom Island (Seogwipo-si, Jeju-do, Korea). A single individual of a newly recorded species in Korea, Coeloplana bocki Komai, 1920, was collected together with C. anthostella from the same location on 16 August 2009. A large number of individuals of each species were subsequently collected from the host Dendronephthya aff. dendritica on 20 June 2010. C. bocki can be distinguished from C. anthostella Song and Hwang, 2010 and C. komaii Utinomi, 1963 by its unique blue and orange colored stripes, and/or the branching and anastomosing milky-white stripes encircling the aboral sense organ towards the margin. The detailed morphology and molecular sequence information (nuclear 18S rDNA, internal transcribed spacer 1, and mitochondrial cox1 gene sequences) for C. bocki is provided, and C. bocki and C. anthostella are compared.

• Animal Systematics, Evolution and Diversity
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• v.29 no.4
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• pp.267-271
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• 2013

In Japan, the wild house mouse Mus musculus consists of two lineages, one from Southeast Asia (Mus musculus castaneus; CAS) and one from northern Eurasia (Mus musculus musculus; MUS). However, the exact origins of the parental lineages are unclear. A recent work using mitochondrial sequences revealed that Japanese CAS and MUS are closely related to haplotypes from South China and the Korean Peninsula, respectively. Recent phylogeographic analyses using nuclear gene sequences have also confirmed a close relationship between Japan and Korea in the MUS component. However, the Japanese CAS components in the nuclear genome are likely to be unique and to differ from those of other CAS territories, including South China. Although the origins are still unresolved, these results allow us to conclude that two areas of the continent, South China and the Korean Peninsula, are the primary source areas of Japanese wild mice and suggest pre-historical introductions associated with certain historical agricultural developments in East Asia.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.3
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• pp.89-97
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• 1997

A genetic algorithm (GA) is a stochastic direct search strategy that mimics the process of genetic evolution. The GA applied herein works on a population of structural designs at any one time, and uses a structured information exchange based on the principles of natural selection and wurvival of the fittest to recombine the most desirable features of the designs over a sequence of generations until the process converges to a "maximum fitness" design. Principles of genetics are adapted into a search procedure for structural optimization. The methods consist of three genetics operations mainly named selection, cross- over and mutation. In this study, a method of finding the optimum topology of truss/beam structure is pro- posed by using the GA. In order to use GA in the optimum topology problem, chromosomes to FEM elements are assigned, and a penalty function is used to include constraints into fitness function. The results show that the GA has the potential to be an effective tool for the optimal design of structures accounting for sizing, geometrical and topological variables.variables.

• Animal Systematics, Evolution and Diversity
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• v.27 no.1
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• pp.1-17
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• 2011

Thais Roding, 1798, commonly known as rock-shell, is among the most frequently found gastropod genera worldwide on intertidal rocky shores including those of Japan, China, Taiwan and Korea. This group contains important species in many marine environmental studies but species-level taxonomy of the group is quite complicated due to the morphological variations in shell characters. This study examined the genetic variations and relationships among three Korean Thais species based on the partial nucleotide sequences of mitochondrial cox1 gene fragments. Phylogenetic trees from different analytic methods (maximum parsimony, neighbor-joining, and maximum likelihood) showed that T. bronni and T. luteostoma are closely related, indicating the most recent common ancestry. The low sequence divergence found between T. luteostoma and T. bronni, ranging from 1.53% to 3.19%, also corroborates this idea. Further molecular survey using different molecular marker is required to fully understand a detailed picture of the origin for their low level of interspecific sequence divergence. Sequence comparisons among conspecific individuals revealed extensive sequence variations within the three species with maximum values of 2.43% in T. clavigera and 1.37% in both T. bronni and T. luteostoma. In addition, there is an unexpectedly high level of mitochondrial genotypic diversity within each of the three Korean Thais species. The high genetic diversity revealed in Korean Thais species is likely to reflect genetic diversity introduced from potential source populations with diverse geographic origins, such as Taiwan, Hong Kong, and a variety of different coastal regions in South China and Japan. Additional sequence analysis with comprehensive taxon sampling from unstudied potential source populations will be also needed to address the origin and key factors for the high level of genetic diversity discovered within the three Korean Thais species studied.

• Animal Systematics, Evolution and Diversity
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• v.39 no.4
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• pp.264-271
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• 2023

The edible jellyfish Rhopilema esculentum occurs in waters throughout northeastern Asia, including in Korea, China, and Japan. In Korean waters, R. esculentum has appeared in two regions (Gangwha and Muan). Based on the appearance of young medusae and coastal distribution records, these two regions may be key R. esculentum breeding sites. In the present study, we investigate and compare the genetic structure of R. esculentum in the two regions using mitochondrial sequences (16S ribosomal RNA and cytochrome c oxidase subunit I). The genetic diversity of the R. esculentum population at Ganghwa exceeded that of the population at Muan. Despite considerable geographic separation (400 km) between the two regions(Gangwha and Muan), our haplotype network suggests that the Gangwha and Muan populations of R. esculentum are related. The simple and monotonous genetic structure of the Muan population shows that R. esculentum emergence is relatively recent. In contrast, the Gangwha population shows evolution. Moreover, jellyfish of the Gangwha population are genetically diverse and remain constant despite environmental fluctuations in the Han River. The Gangwha area is considered to be the old origin of R. esculentum in Korea.

• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.787-804
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• 2018

Flavor quality is import for determining consumer perception and acceptance of tomato products. In this study, 'Fendou' tomato fruit were harvested at six ripening stages and sampled to investigate the development of flavor-relevant compounds during vine ripening. Results showed that upon the initiation of ripening there was an increase in respiration rate and concomitant ethylene evolution that was associated with increased membrane permeability. In accordance with these physiological changes, flavor-relevant compounds demonstrated different expression patterns as fruit ripened, which contributed to 'red-ripe' flavor characteristics of red-ripe fruit. Based on correlation analysis between ethylene evolution and the flavor-relevant compounds during 'Fendou' tomato ripening and the other researchers' reports, the activation of System 2-dependent autocatalytic ethylene production plays an important role in the development of most flavor-relevant compounds during tomato vine ripening. Overall, our results suggested that most flavor-relevant compounds that accumulated the most during tomato fruit ripening at red stage could be under ethylene regulation and were among the most important contributors to the 'red-ripe' flavor. Due to the development of these compounds, the flavor quality at late ripening stages is different from that of fruit at early ripening stages.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.695-703
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• 1999

We have studied the stereospecificities of various pyridoxal 5'-phosphate (PLP) dependent enzymes for the hydrogen transfer between the C-4' of a bound coenzyme and the C-2 of a substrate in the transamination catalyzed by the enzymes. Stereospecificities reflect the structures of enzyme active-sites, in particular the geometrical relationship between the coenzyme-substrate Schiff base and the active site base participating in an $\alpha$-hydrogen abstraction. The PLP enzymes studied so far catalyze only a si-face specific (pro-S) hydrogen transfer. This stereochemical finding suggests that the PLP enzymes have the same topological active-site structures, and that the PLP enzymes have evolved divergently from a common ancestral protein. However, we found that o-amino acid aminotransferase, branched chain L-amino acid aminotransferase, and 4-amino-4-deoxychorismate lyase, which have significant sequence homology with one another, catalyze a re-face specific (pro-R) hydrogen transfer. We also showed that PLP-dependent amino acid racemases, which have no sequence homology with any aminotransferases, catalyze a non-stereospecific hydrogen transfer: the hydrogen transfer occurs on both faces of the planar intermediate. Crystallographical studies have shown that the catalytic base is situated on the re-face of the C-4' of the bound coenzyme in o-amino acid aminotransferase and branched chain L-amino acid aminotransferase, whereas the catalytic base is situated on the si-face in other aminotransferases (such as L-aspartate aminotransferase) catalyzing the si-face hydrogen transfer. Thus, we have clarified the stereospecificities of PLP enzymes in relation with the primary structures and three-dimensional structures of the enzymes. The characteristic stereospecificities of these enzymes for the hydrogen transfer suggest the convergent evolution of PLP enzymes.