• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 추계학술대회 및 정기총회
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• pp.41-41
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• 2015

Oomycetes belong to the kingdom Straminipila, a remarkably diverse group which includes brown algae and planktonic diatoms, although they have previously been classified under the kingdom Fungi. These organisms have evolved both saprophytic and pathogenic lifestyles, and more than 60% of the known species are pathogens on plants, the majority of which are classified into the order Peronosporales (includes downy mildews, Phytophthora, and Pythium). Recent phylogenetic investigations based on DNA sequences have revealed that the diversity of oomycetes has been largely underestimated. Although morphology is the most valuable criterion for their identification and diversity, morphological species identification is time-consuming and in some groups very difficult, especially for non-taxonomists. DNA barcoding is a fast and reliable tool for identification of species, enabling us to unravel the diversity and distribution of oomycetes. Accurate species determination of plant pathogens is a prerequisite for their control and quarantine, and further for assessing their potential threat to crops. The mitochondrial cox2 gene has been widely used for identification, taxonomy and phylogeny of various oomycete groups. However, recently the cox1 gene was proposed as a DNA barcode marker instead, together with ITS rDNA. To determine which out of cox1 or cox2 is best suited as universal oomycete barcode, we compared these two genes in terms of (1) PCR efficiency for 31 representative genera, as well as for historic herbarium specimens, and (2) in terms of sequence polymorphism, intra- and interspecific divergence. The primer sets for cox2 successfully amplified all oomycete genera tested, while cox1 failed to amplify three genera. In addition, cox2 exhibited higher PCR efficiency for historic herbarium specimens, providing easier access to barcoding type material. In addition, cox2 yielded higher species identification success, with higher interspecific and lower intraspecific divergences than cox1. Therefore, cox2 is suggested as a partner DNA barcode along with ITS rDNA instead of cox1. Including the two barcoding markers, ITS rDNA and cox2 mtDNA, the multi-locus phylogenetic analyses were performed to resolve two complex clades, Bremia lactucae (lettuce downy mildew) and Peronospora effuse (spinach downy mildew) at the species level and to infer evolutionary relationships within them. The approaches discriminated all currently accepted species and revealed several previously unrecognized lineages, which are specific to a host genus or species. The sequence polymorphisms were useful to develop a real-time quantitative PCR (qPCR) assay for detection of airborne inoculum of B. lactucae and P. effusa. Specificity tests revealed that the qPCR assay is specific for detection of each species. This assay is sensitive, enabling detection of very low levels of inoculum that may be present in the field. Early detection of the pathogen, coupled with knowledge of other factors that favor downy mildew outbreaks, may enable disease forecasting for judicious timing of fungicide applications.

• Animal cells and systems
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• 제12권4호
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• pp.269-277
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• 2008

Siberian flying squirrel, an endangered species in South Korea, is distributed through major mountain regions of South Korea. The number of Siberian flying squirrel(Pteromys volans) in South Korea has decreased and their habitats are fragmented and isolated because of anthropogenic activities. So far no molecular genetic data has, however, been available for their conservation and management. To obtain better information concerning genetic diversity and phylogenetic relationships of the Siberian flying squirrel in South Korea, we examined 14 individuals from South Korea, 7 individuals from Russia, and 5 individuals from northeastern China along with previously published 29 haplotypes for 1,140 bp of the mtDNA cytochrome b gene. The 14 new individuals from South Korea had 7 haplotypes which were not observed in the regions of Russia and Hokkaido. The level of genetic diversity(0.616%) in the South Korean population was lower than that in eastern Russia(0.950%). The geographical distribution of mtDNA haplotypes and reduced median network confirmed that there are three major lineages of Siberian flying squirrel, occupying; Far Eastern, northern Eurasia, and the island of Hokkaido. The South Korean population only slightly distinct from the Eurasia, and eastern Russian population, and is part of the lineage Far Eastern. Based on these, we suggest that the South Korean population could be considered to belong to one partial ESU(Far Eastern) of three partial ESUs but a different management unit. However, the conservation priorities should be reconfirmed by nuclear genetic marker and ecological data.

• 생명과학회지
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• 제26권7호
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• pp.819-825
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• 2016

이 논문은 제주도에서 채집한 구멍갈파래(Ulva pertusa)를 Restriction Fragment Length Polymorphism (RFLP)를 이용하여 세균군집을 조사하였다. RFLP 분석을 위해 Marine agar배지와 R2A배지를 사용하여 145개의 균주가 분리되었으며, 제한효소 HaeⅢ와 RsaⅠ을 이용하여 서로 다른 RFLP 패턴을 구분하였다. RFLP 패턴 결과로부터 균주를 선별하여 16S rRNA 유전자 염기서열 분석 결과, 알려진 균주의 염기서열과 91% 이상의 유사도를 보였다. 주요 계통군은 Proteobacteria (Alpha-proteobacteria, Beta-proteobacteria, Gamma-proteobacteria) (63%), Bacteroidetes (22%), Firmicutes (11%), Actinobacteria (4%)로 4개의 문이 관찰되었고, 7개의 강, 13개의 목, 18개의 과, 27개의 속으로 관찰되었다. 계통학적 분석 결과, 상동성이 97% 미만으로 나타난 10균주가 새로운 속이나 종으로 분류될 가능성이 높게 나타났으며, 신종 후보 균주에 대한 형태학적, 생리학적, 생화학적 등 분류·동정을 위한 추가적인 실험을 수행해야 할 것이다.

• Journal of Plant Biotechnology
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• 제43권2호
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• pp.151-156
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• 2016

약용 식물 자원은 천연 화장품 소재, 제약 산업 그리고 인간의 건강을 위한 기능성 식품의 개발로 확대 된 이후 중요한 자산이 되고 있다. 그러나 세계적으로 약용 식물의 명칭을 각각 다르게 표기하고 있으며 계통 발생학적 기원이 명확하지 않다는 단점을 지니고 있다. 이 때문에 소비자들은 매우 큰 혼란을 겪고 있으며 특히 형태학적으로 유사한 식물의 말린 뿌리로 유통될 때에는 전문가들도 그들의 기원을 구별하기가 매우 어렵다. 이러한 이유때문에 이처럼 광범위하고 다양한 작물의 기원을 식별하기 위해 분자표지 기법을 적용하여 활용되고 있다. 이 리뷰에서 본 연구자들은 Angelica종의 분화에 관한 적합한 '기원정립'을 위한 현재의 연구 성과들을 정리했다. 결론적으로 Angelica종의 식별을 위해 개발된 분자적 연구에 대해 설명하고 약용작물의 유전체 정보를 활용하여 그들의 기원정립 및 판별에 대해 논의할 것이다.

• 환경생물
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• 제36권4호
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• pp.463-470
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• 2018

본 연구는 국내 염습지 해안 복원의 주요 식물인 갈대와 내건성 대표 식물인 억새의 지역별 유전자형 분석을 통해 지역별 복원종자 적용에 대한 타당성을 검증고자 하는 연구로서, SNP를 활용한 근연관계 분석 결과 억새는 홍성군 집단이 다른 지역과 상이한 유전적 변이를 보인 반면, 갈대는 모든 지역에서 동시다발적인 변이양상이 나타낸다. 이를 통하여 억새의 경우 우리나라 전역에 발생하는 건조지에서 억새시료를 사용할 때는 지역별로 수집한 종자를 활용하는 것이 합리적이나 부득이하게 다른 지역의 식물 자원을 사용한다고 해도 유전적인 교란이 크게 발생하지 않을것으로 보인다. 갈대의 경우 전 지역에서 유전적 변이가 다양하며 억새에 비하여 유전적 변이가 상대적으로 많이 나타나고 있기 때문에 염류 피해지의 복원에 활용할 수 있는 자원인 갈대의 경우 종자를 지역별로 수집하기 위한 다양한 인프라를 구축하여 향후 복원 사업에 대비하여야 한다.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.134-135
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• 2003

The geographic expansion of the toxic dinoflagellates genus Alexandrium has been shown to be world wide ranging. The members of the genus Alexandrium ocnstituted of 20-30 species did not show substantial differences in their morphology, which is mostly referred in the 'tamarensis species complex', except some species. Though rDNA sequences variations are very few and pseudogene types are so diverse that it is difficult to use them as the specific markers. In this study, we outlined Korean and Japanese A, tamarense and A. catenella regional isolates by phylogenetic analysis inferred from no cutting alignments of LSU rDNA D1-D2 and SSU rDNA sequences to group these regional isolates. The results were compared to RFLP patterns of PCR products targeted chloroplast DNA. Lastly screening of highly repeated microsatellite DNA which is frequently used for population analysis in eukaryotes was conducted. A. catenella regional strains identified by the sequencing of rDNA D1-D2 domain were divided into at least 3 groups of type E, CMC and Chinese type, divergence root may not be deep comparing with that of A. tamarense whose pseudogenes are very variable. Results of RFLP pattern and the phylogeny of the unknown gene targeting chloroplast showed that Korean and Japanese A. catenella regional isolates were divided into 3 types: Korean, Japanese and the third CMC types. Population-specific PCR amplification with Japanese A. catenella type-specific PCR primers was useful method for population analysis of A. catenella. Various types of satellite sequences such as 5 nucleotides repeats were obtained from A. tamarense and A. catenella. The 5 nucleotides repeats were primed at the both 3'and 5' ends, and these repeats were prominent as longer repeated motifs. This repeated DNA was intercalated as internal sequences containing various types subrepeats. It is expected that these satellite DNA would be a useful molecular population marker through detail comparison among Alexandrium regional isolates to trace their transferring pathway and to prevent their human-associated their regional extents.

• 한국패류학회지
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• 제26권4호
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• pp.275-283
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• 2010

Many freshwater snail taxa are difficult to identify using morphological traits due to phenotypic plasticity. However, using of molecular DNA marker in combination with morphological traits can provide a reliable means for discriminating among freshwater snail taxa including cryptic species. To discriminate among Korean freshwater snail taxa and resolve their systematic relationships, wesequenced a fragment of mtDNA cytochrome oxidase I (COI) gene from 82 specimens collected from ten different sites distributed along the Korean peninsula. We identified more than seven freshwater snail taxa including cryptic species in Korea. Whereas traditional shell morphology of freshwater snails offers only weak discriminatory power for recognizing 'good' taxa, DNA sequence data provided positive and reliable identification. In addition, a major Semisulcospira clade was clearly separated from the remaining lineages observed including cryptic species. However, a phylogenetic tree inferred from the COI gene data did not fully resolve systematic relationships among pleurocerid taxa in Korea. Establishing more robust shell characteristics for identifying taxa unambiguously and hence improving traditional key shell morphology characters for freshwater snail species is an urgent requirement and will require more rigorous examination of all nominal taxa. While molecular data generated here will be useful for species identification and for describing the systematic relationships among Korean freshwater snails, further analysis will be required.

• Journal of Animal Science and Technology
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• 제54권6호
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• pp.401-409
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• 2012

The objective of this study was to determine genetic variation of five Korean native chicken lines using 30 microsatellite (MS) markers, which were previously recommended by ISAG (International Society for Animal Genetics). The initial study indicated that two microsatellite markers, MCW0284 and LEI0192, were not amplified in these lines and excluded for further analysis. Twenty eight microsatellite markers were investigated in 83 birds from five Korean native chicken lines. The identified mean number of alleles was 4.57. Also, the expected, observed heterozygosity (He, Ho) and polymorphism information content (PIC) values were estimated in these markers and they ranged from 0.31~0.868, 0.145~0.699, and 0.268~0.847, respectively. The results were used for the discrimination of five chicken lines using genetic distance values and also neighbor-joining phylogenetic tree was constructed. Based on the He and PIC values, eighteen markers are enough for the discrimination of these Korean native chicken lines for the expected probability of identity values among genotypes of random individuals (PI), random half sibs ($PI_{half-sibs}$) and random sibs ($PI_{sibs}$). Taken together, these results will help the decision of conservation strategies and establishment of traceability system in this native chicken breed. Also, the use of ISAG-recommended microsatellite markers may indicate that the global comparison with other chicken breeds is possible.

• International Journal of Industrial Entomology and Biomaterials
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• 제35권1호
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• pp.51-57
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• 2017

The tiny dragonfly, Nannophya pygmaea (Odonata: Libellulidae), is an endangered insect in South Korea. Previously, a partial mitochondrial DNA sequence that corresponded to a DNA barcoding region has been used to infer genetic diversity and gene flow. In this study, we additionally sequenced the barcoding region from N. pygmaea that had been collected from three previously sampled populations (40 individuals) and these sequences were combined with the preexisting data. We also selected and sequenced an additional mitochondrial gene (ND5) to find further variable gene regions in the mitochondrial genome. DNA barcoding sequences of 108 individuals from five South Korean localities showed that genetic diversity was highest in Gangjin, Jeollanam-do Province. Muuido, which was previously occupied by a single haplotype, was also found to have an identical haplotype, which confirmed the low genetic diversity on this islet. Gene flow among populations is highly limited, and no clear distance- or region-based geographic partitioning was observed. Phylogenetic relationships among haplotypes showed that there were no discernable haplotypes in South Korea. ND5 provided slightly more haplotypes compared to the barcoding region in 40 individuals (14 vs. 10 haplotypes in the COI gene). It also had a slightly higher within-locality diversity estimate, which suggested that ND5 had potential as mitochondrial DNA-based marker for population genetic analysis.

• Asian-Australasian Journal of Animal Sciences
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• 제21권3호
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• pp.331-339
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• 2008

The genetic structure and diversity of 15 Chinese indigenous chicken breeds was investigated using 29 microsatellite markers. The total number of birds examined was 542, on average 36 birds per breed. A total of 277 alleles (mean number 9.55 alleles per locus, ranging from 2 to 25) was observed. All populations showed high levels of heterozygosity with the lowest estimate of 0.440 for the Gushi chickens, and the highest one of 0.644 observed for Wannan Three-yellow chickens. The global heterozygote deficit across all populations (FIT) amounted to 0.180 (p<0.001). About 16% of the total genetic variability originated from differences between breeds, with all loci contributing significantly to this differentiation. An unrooted consensus tree was constructed using the Neighbour-Joining method and pair-wise distances based on marker estimated kinships. Two main groups were found. The heavy-body type populations grouped together in one cluster while the light-body type populations formed the second cluster. The STRUCTURE software was used to assess genetic clustering of these chicken breeds. Similar to the phylogenetic analysis, the heavy-body type and light-body type populations separated first. Clustering analysis provided an accurate representation of the current genetic relations among the breeds. Remarkably similar breed rankings were obtained with all methods.