• Journal of Life Science
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• v.21 no.9
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• pp.1329-1335
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• 2011

Korean native goats, which are characterized by black coat color, have existed on the Korean peninsula for a long time. Until now, there has been no comprehensive investigation concerning their genetic diversity, phylogenetic analysis or origin. In this study, we investigated the genetic diversity and verified phylogenetic status of the Korean native goat using the 453-bp fragment of the hypervariable fragment I (HVI) of mitochondrial DNA (mtDNA) D-loop region from 60 individuals among 5 populations. The Korean native goat showed less haplotype diversity when compared with goats from other countries. In addition, 6 haplotypes that had not been previously reported were verified in this study. In phylogenetic analyses with other country's goats, 10 haplotypes from Korean native goats were classified into mtDNA lineage A. Moreover, in a phylogenetic tree for goats which contained mtDNA lineage A, 8 of 10 haplotypes could be included in a subgroup with goats from Vietnam and an area of China. However, none of the remaining haplotypes belonged to a major group of Korean native goats and were located on different independent positions. These results suggest that almost Korean native goats aligned more closely to China and Vietnam breeds in mtDNA lineage A and there was no gene flow from other mtDNA lineages. Our results will contribute to conservation strategies and genetic breeding of Korean native goats.

• Nuclear Engineering and Technology
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• v.25 no.4
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• pp.515-528
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• 1993

In a Passive PWR, the successful actuation of Automatic Depressurization System (ADS) is essentially required so that no core damage is occurred following small LOCA. But it has been shown in the previous studies that Core Damage Frequency (CDF) from small LOCA is significantly caused by unavailability of ADS. In this study, the design vulnerabilities impacting the ADS unavailability have been identified and the design improvement items have been proposed through the system reliability assessment using the fault tree methodology The impacts on CDF according to the change of system unavailability have also been analyzed. In addition, small LOCA simulation using RELAP5/MOD3 code has been performed to show the thermal-hydraulic feasibility of the suggested design enhancements.

• Korean Journal of Microbiology
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• v.52 no.2
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• pp.175-182
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• 2016

In this study, we isolated aromatic compounds (lignin polymers) utilizing bacteria in humus layer of oak forest and investigated phylogenetic characteristics and correlation with major bacterial populations in the humus layer by pyrosequencing. Forty-two isolates using aromatic compounds such as p-anisic acid, benzoic acid, ferulic acid and p-coumaric acid were isolated and phylogentic analyses based on 16S rRNA gene sequences showed that the isolates belonged to the genus Rhizobium, Sphingomonas, Burkhorlderia, and Pseudomonas. Among these, Burkhorlderia species which belong to Betaproteobacteria class occupied 83% among the isolates. The bacterial populations in humus layer of oak forest were characterized by next generation pyrosequencing based on 16S rRNA gene sequences. The humus sample produced 7,862 reads, 1,821 OTUs and 6.76 variability index with 97% of significance level, respectively. Bacterial populations consist of 22 phyla and Betaproteobacteria were the major phylum consisting of 15 genera including Burkholderia, Polaromonas, Ralstoria, Zoogloea, and Variovorax. Approximately fifty percentage of them was Burkholderia. Burkholderia as the majority of population in the humus was considered to play a role in degrading lignin in humus layer of oak forest.

• Korean Journal of Ichthyology
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• v.27 no.3
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• pp.165-182
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• 2015

The snailfishes (Scorpaenoidei: Liparidae) is a large group requiring taxonomic reviews because of a potential taxonomic confusion due to its great similarity in external morphology between species and a variation of its body color with size. Molecular phylogeny and taxonomic review were conducted for 10 species in 3 genera reported around the Korean waters, which facilitate understanding interrelationship within its family, and further management of fisheries resources. Molecular phylogeny using mitochondrial COI (mtCOI) and nuclear RAG2 (nRAG2) sequences indicates that the reciprocal monophyly of the three genera (Careproctus, Crystallichthys, and Liparis) were supported except Crystallichthys matsushimae, being closely related to Careproctus notosaikaiensis in only mtDNA COI topology. Liparis ingens Gilbert and Burke (1912) was reported as a distinct species differing from L. ochotensis. However, in the present study, comparing L. ingens from Korea with L. ochotensis from Japan and Russia, the two species were well corresponded in their morphology and molecule, therefore, we suggest L. ingens to be treated as a junior synonym of L. ochotensis.

• Korean Journal of Ecology and Environment
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• v.55 no.3
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• pp.212-220
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• 2022

An estuary is a water ecosystem with a high abundance of the species diversity, due to a variety of complex physicochemical factors of the area where freshwater and ocean mixed. The identification of Corbicula species in the estuary environments is difficult because of various morphological characteristics. In this study, we provide taxonomic information on Corbicula species with taxonomic difficulties using morphological and genetic analysis. This study was conducted on clams from the Seomjin River-Gwangyang Bay, one of the major production area of marsh clam in Korea. As a result, we characterized Cytocrome C Oxidase subunit I (COI) sequences of the Corbicula. The 636 bp nucleotide sequences of COI have 98% homology among Corbicula species collected from 2 sites of Seomjin River-Gwangyang Bay. The phylogenetic analysis with 17 species of Corbicula indicated that most of the species collected from Seomjin River-Gwangyang Bay were brackish water clam (Corbicula japonica), and only one Asian clam (Corbicula fluminea). The evolutionary distance between C. japonica and C. fluminea was less than 0.003. Therefore, it was confirmed that C. japonica is phylogenetically closely related to C. fluminea. In 9 species of Cyrenidae, phylogenetic tree was classified into three lineages. These results will be used as an important data for an identification of clam species by providing genetic information for Corbicula species with a morphological diversity.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.5-11
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• 2024

In this study, the Korean Thyas has been reviewed. We firstly described a species, Thyas coronata (Fabricius, 1775), including detailed illustrations of adult specimens and their reproductive organs. Additionally, we have provided taxonomic diagnoses and distributional information for all Korean Thyas species.

• Animal Systematics, Evolution and Diversity
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• v.12 no.3
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• pp.221-235
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• 1996

The ascidians of Chundo Island are identified into 15 species, 8 genera, 6 families. Among them two species are found to be new to Korean fauna. They are Ascidia sydneiensis Stimpson and Ascidia zara Oka. They are described with figures, and the other species are provided with remarks.

• The Korean Journal of Mycology
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• v.23 no.4 s.75
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• pp.310-317
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• 1995

The evolutionary relationships for 43 species in the taxa of the basidiomycetous yeast and related yeast-like fungi have been studied from the 43 18S rRNA partial sequences. Fibulobasidium inconspicuum showed a relatively close relationship to Filobasidiella neoformans. It is obvious that Tremella foliacea and Ustilogo rabenhorstiana form a independently different cluster from basidiomycetous yeast and seem to be phylogenetically distant from basidiomycetous yeast and each other. The basidiomycetous yeasts are believed more closely associated with Tremella foliacea than with Ustilago rabenhorstiana. The phenotypic criteria such as carotenoid pigments, teliospores, ballistospores seems not to be phylogenetically useful indicators.

• Korean Journal of Plant Taxonomy
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• v.37 no.4
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• pp.419-430
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• 2007

This study was conducted to know the taxonomic features of nuclear ribosomal ITS DNA sequences, ITS1, ITS3 and 5.8S regions, as to nine individuals belonging to four Oxalis species in Korea and an induced species. Sequences of the same regions of sixteen taxa deposited in GenBank were also aligned with those of Korean species as outgroups. The length of ITS sequences aligned in this study is 679 by in total. Evidences, from not only the sequence similarities and divergences but also the phylogenetic and statistical treatments with ITS sequences aligned, were useful for the taxonomy of the genus. The similarity of sequences, among both cauline and acauline taxa, is high as 89% and 95% respectively, but between cauline and acauline taxa, relatively low in the range of 64~69%. The sequence divergences, among both cauline and acauline taxa, is also high as much as 0.36~0.42, but between both cauline and both acauline taxa, low as 0.04~0.06. Two groups between cauline and acauline taxa are paraphyletic, and each group makes a single Glade with a high bootstrap value. The analysis of variance, using ITS sequence aligned, revealed that taxa are significantly different in the level of 0.5%, and O. corymbosa, an induced speices, is also separated from the Korean taxa in the Duncan analysis.

• Korean Journal of Microbiology
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• v.46 no.4
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• pp.359-365
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• 2010

Fifty Actinobacteria strains were isolated from rhizosphere soil of Sasa borealis. In the course of screening for antibacterial activity against bacterial leaf spot of pepper (Xanthomonas axonopodis pv. vesicatoria) of isolates, 12 isolates showed strong antibiotic activity. Basis on the 16S rRNA gene sequence, they were belonging to Streptomyces cluster II. Strain JR-24 exhibited strong antibiotic activity against X. axonopodis pv. vesicatoria, had a minimum inhibitory concentration of 10 ${\mu}l$/disc. The strain JR-24 was most closely related to Streptomyces galbus $DSM40089^T$ (98.1%), Streptomyces longwoodensis $LMG20096^T$ (98%) and Streptomyces capoamus $JCM4734^T$ (97.8%). When assayed with the API 20NE and 50 CHE kit, it is positive for utilization of L-arabinose, D-fructose, D-glucose, D-galactose and hydrolysis of gelatin, protein, starch. The strains contained iso-$C_{14:0}$ (25.93%), iso-$C_{15:0}$ (10.13%), anteiso-$C_{15:0}$ (19.29%) and iso-$C_{16:0}$ (20.35%) as major fatty acids and MK-9 (H4), MK-9 (H6), and MK-9 (H8) as the isoprenoid quinone. Strain JR-24 was suggested new species of genus Streptomyces by nearest neighbors of genotypic relationships and phenotypic characterization. This study was important to microbial resources investigation for environment-friendly agriculture.