• ALGAE
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• v.24 no.3
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• pp.129-138
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• 2009

DNA-based discrimination of species is a powerful way for morphologically otherwise similar species, like centric diatoms. Here, the author sequenced long-range nuclear ribosomal DNAs, spanning from the 18S to the D5 region of the 28S rDNA, of Stephanodiscus, particularly including a Korean isolate. By comparisons, high DNA similarities were detected from the rDNAs of nine Stephanodiscus (>99.4% in 18S rDNA, >98.0% in 28S rDNA). Their genetic distances, however, were significantly different (Kruskal-Wallis test, p < 0.01) compared to two related genera, namely Cyclotella and Discostella. In addition, genetic distances of 18S rDNAs were significantly different (Student’s t-test, p = 0.000) against those of the 28S rDNAs according to individual genera (Cyclotella, Discostella, and Stephanodiscus). Phylogenetic analyses showed that Stephanodiscus and Discostella showed a sister taxon relationship, and their clade was separated from a cluster of Cyclotella (1.00 PP, 100% BP). This suggests that Stephanodiscus has highly conserved sequences of both 18S and 28S rDNA; however, Stephanodiscus is well-separated from other freshwater centric diatoms, such as Cyclotella and Discostella, at the generic level.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.815-820
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• 2008

Two culture-independent methods, namely ribosomal DNA libraries and denaturing gradient gel electrophoresis (DGGE), were adopted to examine the microbial community of a Malaysian light crude oil. In this study, both 16S and 18S rDNAs were PCR-amplified from bulk DNA of crude oil samples, cloned, and sequenced. Analyses of restriction fragment length polymorphism (RFLP) and phylogenetics clustered the 16S and 18S rDNA sequences into seven and six groups, respectively. The ribosomal DNA sequences obtained showed sequence similarity between 90 to 100% to those available in the GenBank database. The closest relatives documented for the 16S rDNAs include member species of Thermoincola and Rhodopseudomonas, whereas the closest fungal relatives include Acremonium, Ceriporiopsis, Xeromyces, Lecythophora, and Candida. Others were affiliated to uncultured bacteria and uncultured ascomycete. The 16S rDNA library demonstrated predomination by a single uncultured bacterial type by >80% relative abundance. The predomination was confirmed by DGGE analysis.

• Animal Systematics, Evolution and Diversity
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• v.37 no.3
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• pp.229-234
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• 2021

Scolelepis (Scolelepis) daphoinos is newly reported in Korean fauna. This species can be distinguished from its congeners by the following characteristics: the presence of reddish pigment patches on the posterior part of the prostomium, notopodial postchaetal lamellae that are partially fused to the branchiae, and the presence of only the bidentate hooded hooks. The morphological diagnosis and photographs of S. (S.) daphoinos are provided. The partial mitochondrial cytochrome c oxidase subunit I (COI), 16S ribosomal DNA(16S rDNA), and the nuclear 18S ribosomal DNA (18S rDNA) sequences from Korean specimens of S. (S.) daphoinos were determined. Species identification was supported by a comparison of DNA barcode sequences of COI and 16S rDNA with morphological examination from the specimens of type locality, China.

• The Korean Journal of Malacology
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• v.12 no.2
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• pp.85-90
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• 1996

3종의 복족류(Rapana venosa, Reishia bronni, Anthosiphonaria sirius)와 1종의 다판류, Lepidosona(Lepidosona) coreanica에 대한 18S ribosomal DNA의 염기서열을 밝히고 이들을 이미 보고된 18종의 이매패류, 2종의 복족류 그리고 1종의 다판류의 염기서열과 비교분석하였다. 그 셜과 복족류는 V4 region에서 다른 연체동물과 구별되는 독특한 inseerted sequinces를 가지고 있었으며, V2 region에서 복족류(Prosobranchia와 Pulmonata)와 이매패류(Pteriomorphia 와Heteerodonta) 각각의 두 아강들이 서로 다른 특징적인 insertions 또는 deletions으로 구분되었다.

• Animal Systematics, Evolution and Diversity
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• v.36 no.3
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• pp.268-273
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• 2020

A spionid polychaete, Boccardiella hamata (Webster, 1879) has been found from mud in crevices between the shells of oysters and adherent substrates in South Korea. The sequences of mitochondrial DNA (mtDNA) cytochrome c oxidase subunit 1 (CO1), 16S ribosomal DNA (16S), and the nuclear 18S ribosomal DNA (18S) from Korean individuals of Boccardiella hamata were determined in the present study. The molecular analysis based on the 18S rRNA gene sequences showed clear separation among the spionid polychaete species, and the sequences of Korean and Japanese individuals are completely identical. The morphological diagnosis and photographs of B. hamata are also provided.

• Animal Systematics, Evolution and Diversity
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• v.38 no.3
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• pp.144-147
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• 2022

The polychaete Scolelepis (Scolelepis) sagittaria was originally described from Japanese waters and subsequently reported from Korean waters. In this study, we determined for the first time the mitochondrial cytochrome c oxidase subunit I (COI), 16S ribosomal DNA (16S rDNA), and nuclear 18S ribosomal DNA (18S rDNA) sequences of Korean specimens of S. (S.) sagittaria. We also assessed intraspecific variation in the shape of the prostomium of this species based on an examination of 247 individuals. All materials were collected from intertidal sandy beaches of the Korea Strait. The molecular data and morphological observations reported herein will contribute to gaining a better understanding of the taxonomic relationships among members of the genus Scolelepis.

• Animal Systematics, Evolution and Diversity
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• v.37 no.4
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• pp.349-353
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• 2021

Scolelepis (Parascolelepis) papillosa (Okuda, 1937), originally described from a single incomplete individual from Jeju Island in Korea, was collected from the intertidal sandflats of Soan Island (Jeollanam-do province) in Korea. The examined specimens of S. (P.) papillosa agree well with the original description in having the papillae on the basal sheath of the palps, presence of occipital antenna, absence of notochaetae in chaetiger 1, branchiae completely fused with notopodial postchaetal lamellae at the anterior chaetigers, and neuropodial hooded hooks appearing from chaetiger 16. In this study, the sequences of partial mitochondrial cytochrome c oxidase subunit I (COI), 16S ribosomal DNA (16S rDNA), and the nuclear 18S ribosomal DNA (18S rDNA) of the species were determined. We also provide the detailed description and illustrations on this species based on the complete specimens newly collected in this study.

• Animal Systematics, Evolution and Diversity
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• v.36 no.4
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• pp.382-386
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• 2020

In this study, Prionospio depauperata Imajima, 1990 is newly reported in Korean fauna. Prionospio depauperata can be distinguished from other relatives by the four pairs of branchiae which are pinnate on chaetigers 2 and 5, and apinnate on chaetigers 3 and 4; caruncle extending to the end of chaetiger 2; and moderate dorsal crest present on chaetigers 7-13. The morphological diagnosis of P. depauperata are provided with the photographs of four Prionospio species. The mitochondrial cytochrome c oxidase subunit 1 (CO1), 16S ribosomal DNA (16S rDNA), and the nuclear 18S ribosomal DNA (18S rDNA) sequences of four Prionospio species from Korean waters, P. depauperata Imajima, 1990, P. japonica Okuda, 1935, P. krusadensis Fauvel, 1929, and P. membranacea Imajima, 1990, were determined for the first time. The inter-specific genetic distances among the congeners of four Prionospio species were 22.3-29.6% in CO1, 10.5-25.0% in 16S rDNA, and 0.3-3.6% in 18S rDNA.

• Animal Systematics, Evolution and Diversity
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• v.38 no.1
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• pp.26-33
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• 2022

Two Pseudopolydora polychaetes, P. bassarginensis and P. reticulata, originally described from Peter the Great Bay in Russia and Taiwan, respectively, were recorded firstly in Korea with DNA information. Two species are known to have distinct morphological characteristics that are separated from other Pseudopolydora species. They are characterized by reticulate pigmentations on the dorsal sides of the anterior chaetigers, a longitudinal black band-like pigmentation on the caruncle, and black paired spots on the ventral sides of the anterior chaetigers. These two species can be distinguished morphologically from each other by the length of the caruncle. Methyl green staining pattern of the species is a good method for delimiting Pseudopolydora species. The partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI), 16S ribosomal DNA (16S rDNA), and the nuclear 18S ribosomal DNA (18S rDNA) from Korean specimens of the two species were determined. The morphological descriptions and images of the two Pseudopolydora species are provided.

• Animal Systematics, Evolution and Diversity
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• v.38 no.2
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• pp.91-97
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• 2022

Spionid polychaete Prionospio kirrae Wilson, 1990 is newly reported from the Yellow Sea in Korea. This species is characterized by four pairs of branchiae, which are apinnate on chaetigers 2-4 and pinnate on chaetiger 5, a caruncle extending to the posterior end of chaetiger 1, the presence of a distinctly high dorsal crest on chaetiger 11, and the presence of tridentate hooded hooks with rounded apical teeth. Sequences of partial mitochondrial cytochrome c oxidase subunit I (COI), 16S ribosomal DNA(16S rDNA), and the nuclear 18S ribosomal DNA(18S rDNA) of the species are determined from Korean specimens.