• Animal Systematics, Evolution and Diversity
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• v.37 no.4
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• pp.354-357
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• 2021

In Korean waters, the cirolanid isopod, Eurydice longiantennata Nunomura and Ikehara, 1985 has been reported only from the subtidal zone of Jeju island. We obtained the mitochondrial cytochrome c oxidase subunit I (COI) sequences of this species and determined the DNA barcoding data of E. longiantennata based on a genetic comparison of E. longiantennata and its congeners. The intra-specific genetic distance between the three COI sequences of E. longiantennata ranged from 0 to 0.6%. The inter-specific distances between E. longiantennata and other cirolanid isopods ranged from 24 to 33.2%. In this study, we provided the DNA information of E. longiantennata with a morphological diagnosis and images of the species.

• Parasites, Hosts and Diseases
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• v.60 no.4
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• pp.289-293
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• 2022

Blastocystis is a genus of unicellular heterokont parasites belonging to a group of organisms known as Stramenopiles, which includes algae, diatoms, and water molds. Blastocystis includes several species that habitat in the gastrointestinal tracts of organisms as diverse as humans, farm animals, birds, rodents, reptiles, amphibians, fish, and cockroaches. It is important to public health and distributed globally, but its prevalence in dogs in Korea has not been reported to date. Here, we collected 787 canine fecal samples and assessed Blastocystis infection by age, sex, region, season, and diarrhea symptoms. We determined Blastocystis subtypes using phylogenetic analyses based on 18S rRNA gene sequences. We identified, 10 Blastocystis positive samples (1.3%). A higher proportion of infected dogs was asymptomatic; however, infection rates did not significantly differ according to region, age, sex, and season. Phylogenetic analysis showed that the Blastocystis sp. identified belonged to 4 subtypes (STs), ST1, ST5, ST10, and ST14, thus revealed the genetic diversity of Blastocystis sp. in dogs Korean. This is first report on the presence of Blastocystis sp. in dogs Korean. This study revealed a lower infection rate than expected and differed from previous studies in STs. Further studies are warranted to observe the national infection status of Blastocystis in dogs and the genetic characteristics of this genus.

• Animal cells and systems
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• v.3 no.3
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• pp.275-283
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• 1999

Korean R. plancyi occupies a restricted area in western South Korea and shows a relatively low level of genic variability (%P＝15.2, Ho=0.052, He＝0.048). In contrast, R. nigromaculata is broadly distributed in South Korea. The observed low level of variability of R. nigromaculata (%P＝14.3, Ho＝0.042, He＝0.043) is probably due to its recent colonization. Populations of R. nigromaculata exhibited considerable genetic differentiation (F$_{sT}$=0.149) and low level of gene flow (Nm＝1.427) among populations, compared to those of R. Plancyi (F$_{sTF$_{sT}$}$=0.096, Nm＝2.354), which occupies a restricted area. The observed levels of gene flow among populations of R. nigromaculata (Nm＝1.427) over a broad geographic range is relatively higher than other amphibian species. The high level of gene flow is probably the result of the high dispersal abilities of R. nigromaculata. A survey of temporal genic variation of R. nigromaculata showed that there was no significant change on the overall average genetic diversity from 1978 (average He＝0.044) to 1997 (average He＝0.040). Wright's F-statistics also indicated no significant genetic differentiation from 1978 (F$_{sT}$＝0.118) to 1997 (F$_{sT}$＝0.108). This suggests that the environmental change appears to have had little influence on the genetic composition of R. nigromaculata in the study areas during the past 20 years. The low level of temporal variation might be due to the result of high dispersal abilities and wide migration range of this species.

• Mycobiology
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• v.49 no.4
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• pp.308-345
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• 2021

Lactifluus (Pers.) Roussel is an ectomycorrhizal genus that was recently recognized to be distinct from the genus Lactarius. To date, 226 Lactifluus species have been reported worldwide. Misidentification of Lactifluus species is common because of intraspecific morphological variation, cryptic diversity, and the limited number of taxonomic keys available. Molecular data are indispensable for species delimitation; a multilocus phylogenetic analysis showed that most Asian Lactifluus species are not conspecific with morphologically similar species present on other continents. In particular, Korea has misused European and North American Lactifluus names. In this study, we evaluated the taxonomy of Lactifluus in Korea using both morphological and multilocus molecular (ITS, nrLSU, rpb1, and rpb2) data. We examined 199 Lactifluus specimens collected between 1980 and 2016, and a total of 24 species across the four Lactifluus subgenera were identified. All Korean species are distinct and clearly separated from European and North American species. Five taxa corresponded to previously described species from Asia and the remaining 19 taxa are confirmed as new species. Herein, we provide keys to the Korean Lactifluus species within their subgenera, molecular phylogenies, a summary of diversity, and detailed description of the new species.

• Journal of Mushroom
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• v.12 no.1
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• pp.41-51
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• 2014

Cauliflower mushroom widely known high concent of ${\beta}$-glucan for farm cultivation invigoration verified characteristics of mycelia growth, genetic diversity, resistance to Trichoderma by replacement culture with Trichoderma and growth characteristics of new variety crossbleeding strain. The result of replacement culture with Trichoderma for verification resistance about Trichoderma, 6951 (T. viride) strain did not show special change after formation of confrontation line and 6952 (T. spp.) strain was showed more formation of spore after formation of confrontation line. But 6426 (T. harzianum) strain found to encroach part of growth area of cauliflower mushroom mycelia. Among 10 kinds cauliflower mushroom strain, JF02-06 strain collected by Gurye, found did not spore of Trichoderma and thought to be resistant to Trichoderma. The result of crossbleeding after selected that mother strain good growth and formation of fruit body, verified good mycelia growth at JF02-47, 49 and 50 strain in Korean pine of wood-chip media. The result of gene sequence about ITS1, 5.8S and ITS4 for analysis of genetic diversity at crossbleeding strain, found high significance to other cauliflower mushroom in registered Genebank. The result of growth characteristic of spore and mycelia of cauliflower mushroom by observation microscope, size of spore showed water drop shape to major axis $6{\mu}m$ and minor axis $5{\mu}m$ and clamp showed 3 types in mycelia. The wide of mycelia was $3{\mu}m$. The characteristic of mycelia of cauliflower mushroom found to grow mycelia in clamp at approximately 50%. The growth speed of mycelia was $0.507{\mu}m/min$ and 2nd mycelia grown similar speed to mother mycelia at parallel with mother mycelia after growth speed at $0.082{\mu}m/min$. The formation of clamp made small clamp for 5 hours after shown transfer of electrolyte in mycelia inside. The septum formation started after 3 hours and then finally completed after 2 hours. In this study, strain of cauliflower mushroom verified resistance of Trichoderma, genetic diversity and characteristic of mycelia growth. Therefore, basic knowledge of cauliflower mushroom will improve and further contribute to development of mushroom industry.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.81-89
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• 2016

Distributed genetic algorithm (DGA), also known as island model or coarse-grained model, is a kind of parallel genetic algorithm, in which a population is partitioned into several sub-populations and each of them evolves with its own genetic operators to maintain diversity of individuals. It is known that DGA is superior to conventional genetic algorithm with a single population in terms of solution quality and computation time. Several researches have been conducted to evaluate effects of parameters on GAs, but there is no research work yet that deals with structure of DGA. In this study, we tried to evaluate performance of various genetic algorithms (GAs) for the famous symmetric traveling salesman problems. The considered GAs include a conventional serial GA (SGA) with IGX (Improved Greedy Crossover) and several DGAs with various combinations of crossover operators such as OX (Order Crossover), DPX (Distance Preserving Crossover), GX (Greedy Crossover), and IGX. Two distinct immigration policies, conventional noncompetitive policy and newly proposed competitive policy are also considered. To compare performance of GAs clearly, a series of analysis of variance (ANOVA) is conducted for several scenarios. The experimental results and ANOVAs show that DGAs outperform SGA in terms of computation time, while the solution quality is statistically the same. The most effective crossover operators are revealed as IGX and DPX, especially IGX is outstanding to improve solution quality regardless of type of GAs. In the perspective of immigration policy, the proposed competitive policy is slightly superior to the conventional policy when the problem size is large.

• Animal Systematics, Evolution and Diversity
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• v.28 no.4
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• pp.279-290
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• 2012

Plecoglossus altivelis (ayu) is an amphidromous fish widely distributed in Northeastern Asia from the East China Sea to the northern Japanese coastal waters, encompassing the Korean Peninsula within its range. The shore lines of northeastern region in Asia have severely fluctuated following glaciations in the Quaternary. In the present study, we investigate the population genetic structure and historical demographic change of P. altivelis at a population level in East Asia. Analysis of molecular variance (AMOVA) based on 244 mitochondrial control region DNA sequences clearly showed that as the sampling scope extended to a larger geographic area, genetic differentiation began to become significant, particularly among Northeastern populations. A series of hierarchical AMOVA could detect the genetic relationship of three closely located islands between Korea and Japan that might have been tightly connected by the regional Tsushima current. Neutrality and mismatch distribution analyses revealed a strong signature of a recent population expansion of P. altivelis in East Asia, estimated at 126 to 391 thousand years ago during the late Pleistocene. Therefore it suggests that the present population of P. altivelis traces back to its approximate demographic change long before the last glacial maximum. This contrasts our a priori expectation that the most recent glacial event might have the most crucial effect on the present day demography of marine organisms through bottleneck and subsequent increase of effective population size in this region.

• Molecules and Cells
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• v.43 no.1
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• pp.86-95
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• 2020

The red-crowned crane (Grus japonensis) is an endangered, large-bodied crane native to East Asia. It is a traditional symbol of longevity and its long lifespan has been confirmed both in captivity and in the wild. Lifespan in birds is known to be positively correlated with body size and negatively correlated with metabolic rate, though the genetic mechanisms for the red-crowned crane's long lifespan have not previously been investigated. Using whole genome sequencing and comparative evolutionary analyses against the grey-crowned crane and other avian genomes, including the long-lived common ostrich, we identified redcrowned crane candidate genes with known associations with longevity. Among these are positively selected genes in metabolism and immunity pathways (NDUFA5, NDUFA8, NUDT12, SOD3, CTH, RPA1, PHAX, HNMT, HS2ST1, PPCDC, PSTK CD8B, GP9, IL-9R, and PTPRC). Our analyses provide genetic evidence for low metabolic rate and longevity, accompanied by possible convergent adaptation signatures among distantly related large and long-lived birds. Finally, we identified low genetic diversity in the red-crowned crane, consistent with its listing as an endangered species, and this genome should provide a useful genetic resource for future conservation studies of this rare and iconic species.

• The Korean Journal of Ecology
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• v.24 no.6
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• pp.359-364
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• 2001

Regional variations of Dictyostelid cellular slime molds were examined using molecular data. The intertranscribed spacer regions including the 5.8S ribosomal DNA of 2 species(D. purpureum, P. violaceum) of Cellular Slime Molds were sequenced and analyzed. Among 13 strains of D. purpureum and 12 strains of P. violaceum analyzed, each two strains were obtained from ATCC and the others were isolated from the forest soils in Korea. The sequences of the 5.8S ribosomal DNA were conserved among the strains of the same species, but unexpectedly highly variable among species. A high level of genetic diversity was found which was best resolved at the genus/species level as well as the family level by sequence data from the ITS 1 and ITS 2 regions. According to the sequence alignments by CLUSTAL X and the phylogeographic analyses by PAUP, 12 strains of P. violaceum were divided into three groups among which there were no difference of the morphological characteristics. Among 13 strains of D. purpureum, genetic variations were related to two morphological types, the temperate and subtropical type. There was no variation pattern according to geography in Korea, but there were some variations between Korea and other countries.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.11-11
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• 2017

The most drought resistant among the five most important cereal crops, and a key dual-use (grain and biomass) crop in regions containing some of the world's most degraded soils, sorghum has inherent climate resilience that is likely to become more important under environmental conditions that are projected by many climate change models. The importance of sorghum might be further elevated by the development of productive genotypes that increase the extent and duration of soil cover beyond those of conventional annual crops, mitigating or even reversing losses of ecological capital through multiple crops from single plantings. Rich genetic and genomic resources have been developed to link Sorghum phenotypic diversity to its molecular basis, and in particular the genus has become a model for dissecting the molecular control of perenniality. Nature has made Sorghum perennial at least twice, and crosses between wild perennials and cultivated sorghums show the feasibility of developing genotypes with varying degrees of investment in perenniality while still providing harvestable food, feed, sugar and/or cellulose. Genetic analysis of progeny from these crosses is revealing the hereditary basis of traits related to ratooning and perenniality and providing diagnostic DNA markers. One perennial Sorghum species has adapted to continents and latitudes far beyond the reach of its progenitors, surviving stresses year after year that are only periodically experienced by conventional (annual) sorghum, and may also harbor novel alleles that may mitigate production challenges in conventional annual sorghums.