• Animal Systematics, Evolution and Diversity
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• 제18권1호
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• pp.165-179
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• 2002

백만종을 넘어 천만종에 이를 것으로 추산되는 절지동물 (Phylum Arthropoda)은 지구상에 현존하는 가장 번성한 동물군 중의 하나로서 캠브리아기 생물의 빅뱅 이후 급변하는 환경속에서도 멸종의 길을 걷지 않고 성공적으로 살아남아 오늘날의 다양성을 유지하고 있다. 멸종한 절지동물인 삼엽충(Trilobita)을 제외하면, 현재 서식하고 있는 절지동물들은 다섯 아문으로 나누어진다: 육각류(Hexapoda), 갑각류(Crustacea), 다지류(Myriapoda) 협각류 (Chelicerata), 바다거미류(Pycnogonida), 계통분류학자들은 절지동물과 인접분류군들 (arthropod relatives) -유조동물(Onychophora), 완보동물(Tardigrada), 오구동물(Pentastomida)-의 상호 유연관계와 선구통물 내에서의 계통학적 위치들, 절지동물의 단계통성 혹은 다계통성, 절지동물의 주요 다섯 아문들 간의 계통유연관계 등에 관한 논쟁들을 지난 세기 내내 이어왔다. 최근에 선구등불을 크게 탈피동물 (Ecdysozoa)과 촉수담륜동물 (Lophotrochozoa)로 나누고 탈피동물 내에서 절지동물의 인접분류군 중의 하나가 선형동물 (Nematoda)일 수 있다는 새로운 동물 계통이 발표된 바 있다. 본 종설에서는 이 체계를 기본으로하여 선구동물 내에서의 절지동물과 그 인접분류군들의 계통학적 위치 및 상호유연관계를 우선적으로 언급하므로서 문(Phylum) 준위에서의 절지동물 계통에 관한 논쟁들을 소개하고자 한다. 그 연후에 적지동물의 단계통성에 관한 논쟁, 절지동물 주요 네 그룹 (아문)간의 계통유연관계에 관한 논쟁들에 초점을 맞추어 논하고자 한다. 절지동물의 주요 다섯 아문 중 하나인 바다거미류 (상대적으로 작은 분류군임)의 경우, 다른 주요 네 그룹 (Euarthropoda)의 자매 군으로서 가장 원시적인 형태의 절지류인지, 아니면 협각류의 자매군인지가 논란이 되고는 있을지라도 본 종설에서는 비중있게 다루지 않았다.

• 한국토양동물학회:학술대회논문집
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• 한국토양동물학회 2001년도 총회 및 추계 학술발표대회
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• pp.1-2
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• 2001

• Mycobiology
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• 제50권4호
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• pp.189-202
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• 2022

An investigation of species of the genus Aspergillus present in arthropod, freshwater, and soil led to the discovery of seven undescribed species in Korea. Based on their morphological characteristics and molecular phylogeny analyses using a combined data set of β-tubulin (BenA) and calmodulin (CaM) sequences, the isolated strains CNUFC IGS2-5, CNUFC YJ1-19, CNUFC WD27, CNUFC U8-70, CNUFC AS2-24, CNUFC S32-1, and CNUFC U7-48, were identified as Aspergillus brunneoviolaceus, A. capensis, A. floccosus, A. inflatus, A. parvulus, A. polyporicola, and A. spelaeus, respectively. In the present study, the detailed morphological descriptions and phylogenetic relationships of these species are provided.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
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• pp.116.2-116
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• 2003

No Abstract, See Full Text

• Molecules and Cells
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• 제24권3호
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• pp.351-357
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• 2007

Regions (about 3.7-3.8 kb) of the mitochondrial genomes (rrnL-cox1) of two tardigrades, a heterotardigrade, Batillipes pennaki, and a eutardigrade, Pseudobiotus spinifer, were sequenced and characterized. The gene order in Batillipes was $\underline{rrnL}-\underline{V}-\underline{rrnS}-\underline{Q}-\underline{I}$-M-nad2-W-$\underline{C}-\underline{Y}$-cox1, and in Pseudobiotus it was $\underline{rrnL}-\underline{V}-\underline{rrnS}-\underline{Q}$-M-nad2-W-$\underline{C}-\underline{Y}$-cox1. With the exception of the trnI gene, the two tardigrade regions have the same gene content and order. Their gene orders are strikingly similar to that of the chelicerate Limulus polyphemus (rrnL-V-rrnS-CR-I-Q-M-nad2-W-C-Y-cox1), which is considered to be ancestral for arthropods. Although the tardigrades do not have a distinct control region (CR) within this segment, the trnI gene in Pseudobiotus is located between rrnL-trnL1 and trnL2-nad1, and the trnI gene in Batillipes is located between trnQ and trnM. In addition, the 106-bp region between trnQ and trnM in Batillipes not only contains two plausible trnI genes with opposite orientations, but also exhibits some CR-like characteristics. The mitochondrial gene arrangements of 183 other protostomes were compared. 60 (52.2%) of the 115 arthropods examined have the M-nad2-W-C-Y-cox1 arrangement, and 88 (76.5%) the M-nad2-W arrangement, as found in the tardigrades. In contrast, no such arrangement was seen in the 70 non-arthropod protostomes studied. These are the first non-sequence molecular data that support the close relationship of tardigrades and arthropods.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 춘계학술대회 및 임시총회
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• pp.27-28
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• 2014

Beauveria bassiana (Cordycipitaceae, Hypocreales, Ascomycota) is an anamorphic fungus having a potential to be used as a biological control agent because it parasitizes a wide range of arthropod hosts including termites, aphids, beetles and many other insects. A number of bioactive secondary metabolites (SMs) have been isolated from B. bassiana and functionally verified. Among them, beauvericin and bassianolide are cyclic depsipeptides with antibiotic and insecticidal effects belonging to the enniatin family. Non-ribosomal peptide synthetases (NRPSs) play a crucial role in the synthesis of these secondary metabolites. NRPSs are modularly organized multienzyme complexes in which each module is responsible for the elongation of proteinogenic and non-protein amino acids, as well as carboxyl and hydroxyacids. A minimum of three domains are necessary for one NRPS elongation module: an adenylation (A) domain for substrate recognition and activation; a tholation (T) domain that tethers the growing peptide chain and the incoming aminoacyl unit; and a condensation (C) domain to catalyze peptide bond formation. Some of the optional domains include epimerization (E), heterocyclization (Cy) and oxidation (Ox) domains, which may modify the enzyme-bound precursors or intermediates. In the present study, we analyzed genomes of B. bassiana and its allied species in Hypocreales to verify the distribution of NRPS-encoding genes involving biosynthesis of beauvericin and bassianolide, and to unveil the evolutionary processes of the gene clusters. Initially, we retrieved completely or partially assembled genomic sequences of fungal species belonging to Hypocreales from public databases. SM biosynthesizing genes were predicted from the selected genomes using antiSMASH program. Adenylation (A) domains were extracted from the predicted NRPS, NRPS-like and NRPS-PKS hybrid genes, and used them to construct a phylogenetic tree. Based on the preliminary results of SM biosynthetic gene prediction in B. bassiana, we analyzed the conserved gene orders of beauvericin and bassianolide biosynthetic gene clusters among the hypocrealean fungi. Reciprocal best blast hit (RBH) approach was performed to identify the regions orthologous to the biosynthetic gene cluster in the selected fungal genomes. A clear recombination pattern was recognized in the inferred A-domain tree in which A-domains in the 1st and 2nd modules of beauvericin and bassianolide synthetases were grouped in CYCLO and EAS clades, respectively, suggesting that two modules of each synthetase have evolved independently. In addition, inferred topologies were congruent with the species phylogeny of Cordycipitaceae, indicating that the gene fusion event have occurred before the species divergence. Beauvericin and bassianolide synthetases turned out to possess identical domain organization as C-A-T-C-A-NM-T-T-C. We also predicted precursors of beauvericin and bassianolide synthetases based on the extracted signature residues in A-domain core motifs. The result showed that the A-domains in the 1st module of both synthetases select D-2-hydroxyisovalerate (D-Hiv), while A-domains in the 2nd modules specifically activate L-phenylalanine (Phe) in beauvericin synthetase and leucine (Leu) in bassianolide synthetase. antiSMASH ver. 2.0 predicted 15 genes in the beauvericin biosynthetic gene cluster of the B. bassiana genome dispersed across a total length of approximately 50kb. The beauvericin biosynthetic gene cluster contains beauvericin synthetase as well as kivr gene encoding NADPH-dependent ketoisovalerate reductase which is necessary to convert 2-ketoisovalarate to D-Hiv and a gene encoding a putative Gal4-like transcriptional regulator. Our syntenic comparison showed that species in Cordycipitaceae have almost conserved beauvericin biosynthetic gene cluster although the gene order and direction were sometimes variable. It is intriguing that there is no region orthologous to beauvericin synthetase gene in Cordyceps militaris genome. It is likely that beauvericin synthetase was present in common ancestor of Cordycipitaceae but selective gene loss has occurred in several species including C. militaris. Putative bassianolide biosynthetic gene cluster consisted of 16 genes including bassianolide synthetase, cytochrome P450 monooxygenase, and putative Gal4-like transcriptional regulator genes. Our synteny analysis found that only B. bassiana possessed a bassianolide synthetase gene among the studied fungi. This result is consistent with the groupings in A-domain tree in which bassianolide synthetase gene found in B. bassiana was not grouped with NRPS genes predicted in other species. We hypothesized that bassianolide biosynthesizing cluster genes in B. bassiana are possibly acquired by horizontal gene transfer (HGT) from distantly related fungi. The present study showed that B. bassiana is the only species capable of producing both beauvericin and bassianolide. This property led to B. bassiana infect multiple hosts and to be a potential biological control agent against agricultural pests.