• 한국어류학회지
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• 제26권4호
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• pp.274-280
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• 2014

강도다리(Platichthys stellatus)의 정자는 대부분의 경골어류에서와 같이 첨체를 가지고 있지 않는 구형의 핵, 짧은 중편 및 꼬리를 가진 전형적인 수중형의 정자 형태를 하였다. 정자의 미세구조는 전자밀도가 높은 염색질 부위를 가지는 핵과 핵 기부에 위치한 깊이 함입된 핵와(nuclear fossa) 그리고 그 속에 기부 중심립과 말단부 중심립이 포함되어 있었다. 두 중심립은 90도의 각도로 배열되어 있었으며, 미토콘드리아는 중편 세포질에 배열되어 있으며 핵의 후반부와 꼬리의 기부를 둘러 싸고 있었다. 꼬리는 축사와 2개의 lateral ribbon로 구성되어 있었다. 이러한 특징들은 가자미류의 공유형질로 나타났다. 그러나 미토콘드리아의 수와 모양, 핵와의 모양과 크기에서는 종 특이적 특징을 나타내었다. 특히 강도다리 정자의 가장 큰 구조적 특징은 basal foot, rootlet 그리고 alar sheets로 구성된 기저체이었다. 이 구조의 형태적 특징은 다른 종들 사이에서 아주 다양하게 나타내었다. 이러한 구조는 가자미목의 계통적 관계를 연구하는데 매우 중요한 형질로 여겨진다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제34권7호
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• pp.595-602
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• 2007

본 논문에서는 미지의 아미노산 서열이 신호 펩티다제 I에 의해 절단되는 분비성 단백질인지를 판별하고, 분비성 단백질일 경우에는 절단 위치를 예측하는 방법을 제안한다. 아미노산의 소수성을 이용한 전처리를 수행하여 분비성 단백질의 선도서열인 신호서열의 존재와 절단 위치를 추정한다. 전처리를 통해서 신호서열 아닌 서열을 초기에 제외함으로써 신호서열 예측의 정확도를 높인다. 지지벡터기계를 신호서열의 예측에 효과적으로 적용하기 위해서, 생물학적 정보와 관련된 아미노산 서열간의 거리를 제안한다. 아미노산의 세포내 위치를 예측할 수 있는 소수성 척도와 아미노산의 진화적인 관계를 나타낼 수 있는 치환행렬을 이용하여 아미노산 서열간의 거리를 정의한다. Swiss-Prot release 50 단백질 자료에 대하여 교차타당성 기법을 사용하여 실험한 결과 제안한 방법은 신호서열중에 98.9%를 신호서열로 판별하였고, 88%의 절단위치 예측정확도를 보였다. 기존의 방법과의 비교실험을 통해서 제안한 방법이 신호서열의 예측에 더욱 효과적임을 확인하였다.

• 식물분류학회지
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• 제48권4호
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• pp.278-288
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• 2018

Polyploidization plays an important role in generating the current high diversity of plants. Studies of the distributional patterns of diploid and derivative polyploid races have provided important insights into the evolutionary process and cryptic speciation by polyploidization within and between closely related taxa defined on the basis of their morphology. Allium thunbergii and A. sacculiferum, occurring throughout eastern Russia, eastern China, Korea, and Japan, are examples of closely related species with unsolved taxonomic relationships. A total of 97 and 65 individuals from 26 and 13 populations of A. thunbergii (including var. thunbergii, var. deltoids, and var. teretifolium) and A. sacculiferum, respectively, were studied to determine their ploidy. The geographic structure and habitat differentiation of the cytotypes were also analyzed. The main cytotype of A. thunbergii was diploid (92.3% in total; the rest were tetraploids). In contrast, the majority of A. sacculiferum plants were tetraploids (69.2% of the total; the rest were diploids). No populations of the studied taxa harbored both cytotypes. Allium thunbergii was more often found at higher elevations than A. sacculiferum, and it tended to occur more frequently on rocky slopes and below forests in mountainous areas. On the other hand, A. sacculiferum occurred at forest margins and in lowland pastures. The cytotypes differed with respect to the elevation; diploids were found more frequently at higher elevations than tetraploids. The results of this study and additional biosystematics data indicate that the morphological characteristics of A. thunbergii and A. sacculiferum may be influenced by polyploidization and by their adaptation to various habitat conditions and that A. thunbergii and A. sacculiferum do not clearly fulfill the requirements of any species concept. Consequently, we propose that A. sacculiferum be considered as an additional synonym of A. thunbergii. Additionally, Allium thunbergii var. deltoides is unified into A. thunbergii var. thunbergii.

• Animal Bioscience
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• 제34권6호
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• pp.941-948
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• 2021

Objective: In Japan, approximately 50 breeds of indigenous domestic chicken, called Japanese native chickens (JNCs), have been developed. JNCs gradually became established based on three major original groups, "Jidori", "Shoukoku", and "Shamo". Tosa-Jidori is a breed of Jidori, and archival records as well as its morphologically primitive characters suggest an ancient origin. Although Jidori is thought to have been introduced from East Asia, a previous study based on mitochondrial D-loop sequences demonstrated that Tosa-Jidori belongs to haplogroup D, which is abundant in Southeast Asia but rare in other regions, and a Southeast Asian origin for Tosa-Jidori was therefore suggested. The relatively small size of the D-loop region offers limited resolution in comparison with mitogenome phylogeny. This study was conducted to determine the phylogenetic position of the Tosa-Jidori breed based on complete mitochondrial D-loop and mitogenome sequences, and to clarify its evolutionary relationships, possible maternal origin and routes of introduction into Japan. Methods: Maximum likelihood and parsimony trees were based on 133 chickens and consisted of 86 mitogenome sequences as well as 47 D-loop sequences. Results: This is the first report of the complete mitogenome not only for the Tosa-Jidori breed, but also for a member of one of the three major original groups of JNCs. Our phylogenetic analysis based on D-loop and mitogenome sequences suggests that Tosa-Jidori individuals characterized in this study belong to the haplogroup D as well as the sub-haplogroup E1. Conclusion: The sub-haplogroup E1 is relatively common in East Asia, and so although the Southeast Asian origin hypothesis cannot be rejected, East Asia is another possible origin of Tosa-Jidori. This study highlights the complicated origin and breeding history of Tosa-Jidori and other JNC breeds.

• Journal of Animal Science and Technology
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• 제63권6호
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• pp.1411-1422
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• 2021

Lactobacillus acidophilus is a gram-positive, microaerophilic, and acidophilic bacterial species. L. acidophilus strains in the gastrointestinal tracts of humans and other animals have been profiled, but strains found in the canine gut have not been studied yet. Our study helps in understanding the genetic features of the L. acidophilus C5 strain found in the canine gut, determining its adaptive features evolved to survive in the canine gut environment, and in elucidating its probiotic functions. To examine the canine L. acidophilus C5 genome, we isolated the C5 strain from a Korean dog and sequenced it using PacBio SMRT sequencing technology. A comparative genomic approach was used to assess genetic relationships between C5 and six other strains and study the distinguishing features related to different hosts. We found that most genes in the C5 strain were related to carbohydrate transport and metabolism. The pan-genome of seven L. acidophilus strains contained 2,254 gene families, and the core genome contained 1,726 gene families. The phylogenetic tree of the core genes in the canine L. acidophilus C5 strain was very close to that of two strains (DSM20079 and NCFM) from humans. We identified 30 evolutionarily accelerated genes in the L. acidophilus C5 strain in the ratio of non-synonymous to synonymous substitutions (dN/dS) analysis. Five of these thirty genes were associated with carbohydrate transport and metabolism. This study provides insights into genetic features and adaptations of the L. acidophilus C5 strain to survive the canine intestinal environment. It also suggests that the evolution of the L. acidophilus genome is closely related to the host's evolutionary adaptation process.

• ALGAE
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• 제38권4호
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• pp.253-264
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• 2023

The Ceramiales is the most diverse and species-rich group (2,669 spp.) of red algae, and it is widely distributed from tropical to polar oceans. Mitochondrial genomes (mitogenomes) and other genes have contributed to our knowledge regarding the classification and phylogeny of this diverse red algal group; however, the mitogenome architecture remains understudied. Here, we compared 42 mitogenomes, including 19 newly generated in this study, to expand our knowledge. The number of genes in mitogenome varied from 43 to 68 due to gene duplication. The mitogenome architecture was also variable, categorized into four types (A-D): type A = ancestral type with a basic composition; type B = those with inverse transpositions; type C = those with inverted duplications; and type D = those with both inversion and duplication. The palindromic and inverted repeats were consistently found in flanking regions of the rearrangement, especially near the cob and nad6 genes. The three rearranged mitogenome architectures (types B, C, D) are the first report of these in red algae. Phylogenetic analyses of 23 protein-coding genes supported the current familial classification of the Ceramiales, implying that the diversity of mitogenome architecture preceded the phylogenetic relationships. Our study suggests that palindromic and inverted repeats may drive mitogenome architectural variation.

• 한국균학회지
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• 제27권6호
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• pp.406-411
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• 1999

먹물버섯류 및 주름버섯 유사 균류의 계통학적 유연 관계를 분석하기 위해 계통분류학적 정보를 지니고 있는 rDNA의 ITS(17S, 5.8S, 25S일부 포함)의 염기서열을 밝히고 이들 자료를 근거로 하여 형태적 분류 체계와 비교분석을 하였다. 이번 조사된 종은 총 14종으로서 먹물버섯속 균류 8종, 눈물버섯속 균류 1종, 소똥버섯과 2종, 주름버섯과 1종, 독청버섯과 1종, 복군류 1종이 포함되었다. 종간 염기서열 상동성은 $38.7{\sim}77.2%$였다. 조사된 균류는 크게 4개의 그룹을 형성하였다. 그룹 I에 C. micaceus, C. radians, C. disseminatus, Psathyrella candolleana 등이 포함되었고, 그룹 II에는 C. cinereus, C. echinosporus, C. rhizophorus, C. atramentarius이 조사되었다. 한편, 먹물버섯속 균류의 기준종인 C. comatus는 다른 먹물버섯 그룹들과 분지의 신뢰도가 전혀 없는 것으로 조사되었고 그룹 III에서 주름버섯 유사 복균류인 Podaxis pistillaris 및 신령버섯 Agaricus blazei와의 분지 신뢰도는 87과, 57을 각각 나타내었다. 한편, 눈물버섯속 균류는 그룹 II에 포함되는 결과를 나타내어 형태적 분류체계와 상이한 결과를 도출하였고, 주름버섯 유사복균류인 Podaxis pistillaris는 다른 기타 주름버섯목 균류보다도 C. comatus와 더 밀접한 유연 관계를 나타내어 이들 주름버섯 유사 복균류(secotioid taxa)는 주름버섯목 균류에서 파생된 것임을 확인할 수 있었다. 기준 종으로 알려진 C. comatus는 발생학적 측면에서 다른 절에 있는 먹물버섯 균류와 다른 점이 있음을 이번 조사에서 확인할 수 있었으며 먹물버섯속(屬)의 기준 종은 재 설정되어 할 것으로 사료되었다. 또한 기존의 분류학자들이 주장해온 단일 진화론은 조사된 여러 결과와 비교해 볼 때 적어도 paraphyletic이 거나 polyphyletic일 가능성은 높은 것으로 확인되었다.

• The Plant Pathology Journal
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• 제36권4호
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• pp.305-313
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• 2020

Host shifting and host expansion of fungal plant pathogens increases the rate of emergence of new pathogens and the incidence of disease in various crops, which threaten global food security. Magnaporthe species cause serious disease in rice, namely rice blast disease, as well as in many alternative hosts, including wheat, barley, and millet. A severe outbreak of wheat blast due to Magnaporthe oryzae occurred recently in Bangladesh, after the fungus was introduced from South America, causing great loss of yield. This outbreak of wheat blast is of growing concern, because it might spread to adjacent wheat-producing areas. Therefore, it is important to understand the host range and population structure of M. oryzae and related species for determining the evolutionary relationships among Magnaporthe species and for managing blast disease in the field. Here, we collected isolates of M. oryzae and related species from various Poaceae species, including crops and weeds surrounding rice fields, in Korea and determined their phylogenetic relationships and host species specificity. Internal transcribed spacer-mediated phylogenetic analysis revealed that M. oryzae and related species are classified into four groups primarily including isolates from rice, crabgrass, millet and tall fescue. Based on pathogenicity assays, M. oryzae and related species can infect different Poaceae hosts and move among hosts, suggesting the potential for host shifting and host expansion in nature. These results provide important information on the diversification of M. oryzae and related species with a broad range of Poaceae as hosts in crop fields.

• 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.

• 식물분류학회지
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• 제35권1호
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• pp.7-23
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• 2005

한국산 제비꽃속 35분류군과 일본산 4집단, 군외군 1분류군 등 총 40집단에 대한 계통 유연관계를 알아보기 위하여 핵 rDNA의 internal transcribed spacer(ITS)지역에 대한 염기서열을 분석하였다. 정렬된 염기서열들은 bootstrap을 포함한 parsimony 방법과 neighbor-joining 방법을 통하여 계통수를 평가하였다. 그 결과 진정제비꽃절의 낚시제비꽃아절은 군내군의 가장 기부에 분계조를 형성하였으며, 장백제비꽃절은 노랑제비꽃절과 자매군을 형성하면서 진정제비꽃절의 낚시제비꽃아절과 콩제비꽃아절, 고깔제비꽃아절, 제비꽃아절 사이에서 단계통군을 형성하였다. 진정제비꽃절은 병계원적인 분계조를 형성하였고 4개 아절은 독립적인 분계조를 형성하였지만 계열 수준에서는 구별이 불가능하였다. 세포학적 연구에 기초한 제비꽃속의 분화에서 기본염색체 수 x=10을 갖는 낚시제비꽃아절은 x=6인 군외군에서 독립적으로 분화한 것으로 나타났으며 나머지 분류군들은 x=6인 노랑제비꽃과 장백제비꽃아절로부터 x=10 또는 12인 콩제비꽃과 고깔제비꽃아절을 거쳐 x=12인 제비꽃아절로 분화한 특징을 보였다. 형태적인 변이가 매우 심한 분류군으로 알려진 태백제비꽃(V. albida complex)은 Patellares아절 내에서 하나의 군으로 유집되어 Pinnatae계열로 처리하는 것이 타당할 것으로 생각되며, 뫼제비꽃과 남산제비꽃의 잡종인 우산제비꽃은 형태적 특징에 의한 분류와는 일치하지 않는 것으로 나타났다.