• Molecules and Cells
• /
• 제27권5호
• /
• pp.515-523
• /
• 2009

To infer the monophyletic origin and phylogenetic relationships of the order Desmoscolecida, a unique and puzzling group of mainly free-living marine nematodes, we newly determined nearly complete 18S rDNA sequences for six marine desmoscolecid nematodes belonging to four genera (Desmoscolex, Greeffiella, Tricoma and Paratricoma). Based on the present data and those of 72 nematode species previously reported, the first molecular phylogenetic analysis focusing on Desmoscolecida was done by using neighbor joining (NJ), maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI) methods. All four resultant trees consistently and strongly supported that the family Desmoscolecidae forms a monophyletic group with very high node confidence values. The monophyletic clade of desmocolecid nematodes was placed as a sister group of the clade including some members of Monhysterida and Araeolaimida, Cyartonema elegans (Cyartonematidae) and Terschellingia Iongicaudata (Linhomoeidae) in all the analyses. However, the present phylogenetic trees do not show any direct attraction between the families Desmoscolecidae and Cyartonematidae. Within the monophyletic clade of the family Desmoscolecidae in all of the present phylogenetic trees, there were consistently observed two distinct subgroups which correspond to the subfamilies Desmoscolecinae [Greeffiella sp. + Desmoscolex sp.] and Tricominae [Paratricoma sp. + Tricoma sp].

• 한국자원식물학회지
• /
• 제29권4호
• /
• pp.407-418
• /
• 2016

본 연구는 ITS region과 3개의 엽록체 DNA region을 활용하여 한국산 수국속 7 분류군에 대한 계통학적 유연관계를 규명하고자 수행되었다. 계통학적 분석 결과 한국산 수국속의 7분류군은 단계통군을 형성하였으며, Macrophyllae 아절은 산수국과 수국의 두 개의 분계조로 나뉘었다. 산수국의 분계조는 꽃산수국과 탐라산수국이 유집되어 하나의 단계통군을 형성하였으며, 염기서열상으로도 뚜렷한 차이가 나타나지 않았다. 수국의 분계조는 산수국의 분계조와 독립된 분계조를 형성하며 뚜렷이 구분되었다. 수국속 분계조 내의 Petalanthe, Heteromallae, Calyptranthae 아절은 단계통군을 형성하였지만, Calyptranthae 아절에 속하는 등수국은 한라산 개체를 제외한 제주도 집단과 울릉도, 일본 집단으로 두 개의 소분계조를 이루었다. 등수국의 두 개의 소분계조에 대한 추가적인 연구는 더 많은 양의 채집과 지리학적인 연구가 추가 되어야 할 것으로 판단된다.

• ALGAE
• /
• 제22권2호
• /
• pp.57-67
• /
• 2007

We analyzed the nuclear-encoded large subunit ribosomal RNA gene (LSU rDNA) sequences of 19 dinoflagellates occurring in costal waters off Korea and reconstructed a phylogenetic tree containing 74 representative species from 37 distinct genera. Of these, the LSU rDNA sequences of Amylax triacantha (Jörgensen) Sournia, Gonyaulax verior Sournia (= Amylax diacantha Meunier), Gyrodinium fissum (Levander) Kofoid et Swezy, Katodinium glaucum (Lebour) Lebour III, Noctiluca scintillans (Macartney) Kofoid et Swezy, Oxyphysis oxytoxoides Kofoid, and Pyrophacus steinii (Schiller) Wall et Dale are reported for the first time. Our LSU rDNA tree consistently placed Oxyrrhis marina Dujardin and N. scintillans at the most primitive positions, giving rise to a strongly supported monophyletic group of typical dinoflagellate species belonging to the Dinophyceae. The phylogenetic relationships among the typical dinoflagellates, however, were not resolved in the higher taxonomic levels in general. Only genera at terminal branches were usually supported with high confidence. The Dinophysiales, represented by Dinophysis species and O. oxytoxoides, formed a strongly supported monophyletic assemblage. The Gymnodiniales and Peridiniales were recovered as polyphyletic groupings. Members of the Gonyaulacales were consistently grouped together, but lacked statistical support. Within this order, the Ceratiaceae and Goniodomataceae each formed a monophyletic group, but the Gonyaulacaceae was polyphyletic. The phylogenetic relationships of the Gonyaulacaceae were generally congruent with differences in the combinations of the apical pore complex, hypothecal organization and thecal formula.

• 생태와환경
• /
• 제39권2호통권116호
• /
• pp.265-270
• /
• 2006

The nucleotide sequence variations of mitochondrial DNA were investigated to understand genetic differentiation for five different Pungitius kaibarae populations at five study sites from selected four streams flowing into the East Sea. The complete sequences of mtDNA control regions of them were determined the constant sites 342 bp and variable sites 183 bp including parsimony infromative sites 122 bp. Based on the phylogenetic tree, five populations were monophyletic unit (97% MPand 100% NJ) and separated two groups (Myongpa-Songhuen stream group and others group). The population of Baebong stream (82nd bp, G-A) consistently formed them of the Jasan stream into a monophyletic unit even though it is closer then Myongpa stream (99th bp, T-C) from the Baebong stream. Further studies on the molecular phylogeny for the primary freshwater fish are needed to establish for the fish biodiversity conservation in mountainous and upland streams.

• ALGAE
• /
• 제21권2호
• /
• pp.175-183
• /
• 2006

Recent phylogenetic studies of scytosiphonacean brown algae show many conflicts with current classification. In order to clearly define the phylogenetic relationships of the family, we newly sequenced the photosystem I coding psaA gene (1488 base pairs) from 13 taxa (15 samples), of the family, and, for comparison, rbcL from four taxa. The psaA region has more informative sites (17.9%) than the rbcL (13.1%) and the number of nodes supported by over 50% bootstrap values is more in the psaA phylogeny (53 /57 nodes; 93%) than in the rbcL (47/63 nodes; 74.6%). The psaA phylogenies are basically congruent with the rbcL trees, recognizing two major groups in the monophyletic Scytosiphonaceae. The first group included Myelophycus, Petalonia, Scytosiphon, and elongate sack-shaped species of Colpomenia, primarily cold temperate elements with unilocular zoidangia on sporophytes. The second group, although not resolved, consisted of Hydroclathrus, Chnoospora, Rosenvingea, and ball-shaped Colpomenia, primarily warm-temperate taxa with both unilocular and plurilocular zoidangia on sporophytes. Chnoospora is not monophyletic, as was previously shown the paraphyly of Colpomenia, Petalonia, and Scytosiphon. Hydroclathrus clathratus from Korea and Japan was not monophyletic. Our studies show that gametophytic characters are the main source of conflict for the present taxonomy of the family. The psaA region is a useful tool for resolution of phylogenetic relationships within the Scytosiphonaceae.

• 식물분류학회지
• /
• 제38권4호
• /
• pp.371-388
• /
• 2008

Coryloideae 35집단에 대한 계통 유연관계를 알아보기 위하여 핵 DNA의 waxy 유전자와 엽록체 DNA의 atpB-rbcL intergenic spacer 지역에 대한 염기서열을 분석하였다. Waxy 유전자 분석에서 Coryloideae의 4개 속은 단계통군을 형성하였으며, 개암나무속은 단계통군을 형성하면서 군내군의 가장 기부에 분계조(clade)를 형성하였다. Ostryopsis속은 서어나무속과 새우나무속을 위한 자매군을 형성하였으며, 새우나무속 역시 단계통군을 형성하였다(BS=86, PP=99). AtpB-rbcL 분석에서는 Ostryopsis속이 아과 내에서 가장 기부에 분계조를 형성하였다. 개암나무속은 서어나무속-새우나무속과 Ostryopsis속의 중간에 위치하였고(BS=98, PP=100), 서어나무속은 새우나무속 분류군들과 함께 높은 지지도(BS=100, PP=100)를 가지고 하나의 clade를 형성하였다. Waxy 유전자 분석에서 서어나무속의 Carpinus절은 단계통을 형성하였지만 Distegocarpus절은 병계원군(paraphyletic group)으로 나타났다. 개암나무속의 경우는 2개의 subclade를 형성하였지만 속내 절 또는 아절 등의 분류계급과는 일치하지 않았다. AtpB-rbcL 분석에서는 대부분의 분류군들이 각각의 clade내에서 polytomy를 형성하여 차이를 보였다. 이상의 결과에서 두 유전자의 계통분석 결과가 뚜렷하게 불일치하였고, 특히 Ostryopsis속의 위치와 새우나무속의 단계통 여부, 그리고 서어나무속과 새우나무속의 유연관계가 가장 큰 차이를 보였다. 따라서 이들에 대한 추가적인 연구가 필요한 것으로 판단된다.

• Animal cells and systems
• /
• 제1권1호
• /
• pp.43-52
• /
• 1997

Systematic relationship of 13 species representing seven orders of anthozoans, and one hydrozoan as an outgroup, were investigated. Distance and parsimony methods were used to analyze nucleotide sequence data obtained from the 18S rDNA. The inferred phylogeny indicates that two orders, Ceriantharia and Antipatharia within subclass Ceriantipatharia, are not closely related to each other. Instead, the former appears to be the most ancestral group among anthozoans but the latter is more closely related to order Actiniaria within subclass Zoantharia. The result also indicates that the actiniarian may not be a monophyletic group, because Epiactis Japonica is related more to order Scleractinia. Subclass Octocorallia appears to be a monophyletic group, within which order Pennatulacea diversed at first, and then orders Alcyonacea and Gorgonacea diversed later.

• 한국식물학회:학술대회논문집
• /
• 한국식물학회 2002년도 춘계학술발표대회:발표눈문요지록
• /
• pp.84-84
• /
• 2002

• Mycobiology
• /
• 제51권3호
• /
• pp.139-147
• /
• 2023

Aspergillus sojae has long been considered a domesticated strain of Aspergillus parasiticus. This study delineated relationships among the two species and an Aspergillus PWE36 isolate. Of 25 examined clustered aflatoxin genes of PWE36, 20 gene sequences were identical to those of A. sojae, but all had variations to those of A. parasiticus. Additionally, PWE36 developmental genes of conidiation and sclerotial formation, overall, shared higher degrees of nucleotide sequence identity with A. sojae genes than with A. parasiticus genes. Examination of defective cyclopiazonic acid gene clusters revealed that the PWE36 deletion pattern was identical only to those of A. sojae. Using A. sojae SMF134 genome sequence as a reference, visualization of locally collinear blocks indicated that PWE36 shared higher genome sequence homologies with A. sojae than with A. parasiticus. Phylogenetic inference based on genome-wide single nucleotide polymorphisms (SNPs) and total SNP counts showed that A. sojae strains formed a monophyletic clade and were clonal. Two (Argentinian and Ugandan) A. parasiticus isolates but not including an Ethiopian isolate formed a monophyletic clade, which showed that A. parasiticus population is genetically diverse and distant to A. sojae. PWE36 and A. sojae shared a most recent common ancestor (MRCA). The estimated divergence time for PWE36 and A. sojae was about 0.4 mya. Unlike Aspergillus oryzae, another koji mold that includes genetically diverse populations, the findings that current A. sojae strains formed a monophyletic group and shared the MRCA with PWE36 allow A. sojae to be continuously treated as a species for food safety reasons.

• Animal cells and systems
• /
• 제3권4호
• /
• pp.359-363
• /
• 1999

Urochordates, the most primitive group in phylum Chordata, are mostly sessile as adults although some are free living. Presently, the ancestral stock of urochordates as weir as chordates has been the focus of interest and two conflicting hypotheses have been presented. A free swimming ancestor is one and a sessile, filter feeding ancestor is the other. To clarify the phylogenetic relationships within the urochordates, 22 urochordates and five others as outgroups were used. And we applied neighbor joining, maximum likelihood, and maximum parsimony methods to partial 18S rDNA sequences. The inferred phylogeny in all analyses indicates that order Aplousobranchia of class Ascidiacea appears to be the most ancestral group among urochordates. But it is not clear for the low bootstrap value. The remaining two orders of ascidians, Phlebobranchia and Stolidobranchia, form monophyletic groups respectively, which are well supported by high bootstrap values. These two orders are closer to classes of Thaliacea and Appendicularia than to the Aplousobranchia. While class Appendicularia is strongly supported by the monophyletic group, the phylogenetic position of class Thaliacea is unclear in this study.