• Journal of Life Science
• /
• v.11 no.2
• /
• pp.126-134
• /
• 2001

The phylogenetic tree displayed the presence of five groups in the Phellinus genus, which were distinguished based on their morphology. Most of the p. linteus appeared a cluster which was highly significant with the exception of P. linteus KACC 500122 and KACC 500411. They formed the sister taxa of P 1inteus where P. baumii, Phellinus sp. MPNU 7003, MPNU 7007, and MPNU 7010 had similar morphological characteristics. Also, P. nigricans IMSNU 32024 and P. pini var, carniformans IMSNU 32031 were grouped in the same cluster with P. igniarius KCTC 6227, KCTC 6228, and P. chrysoloma KCTC 6225 extracted from the Gen-Bank database. P. torulosus IMSNU 32028 and Phellinus sp. MPNU 7011 formed a closed group, however, these species had a distant taxa when compared with the other Phellinus species. The nucleotide sequences of the internal transcribed spacer (ITS) regions of ribosomal DNA (rDNA) including the 5.85 rDNA were determined from 24 strains of the Phellinus genus in order to analyze their phylogenetic relationship. These fungi were divided into two basic groups based on their ITS length, however, this grouping was different from that based on their morphological characteristics. Although various ITS sequences were ambiguously aligned, conserved sites were also identified. Accordingly, a neighbor-joining tree was constructed using the nucleotide sequence data of the conserved sites of the ITS regions and the 5.8S rDNA.

• Journal of Life Science
• /
• v.11 no.2
• /
• pp.74-80
• /
• 2001

The nucleotide sequences of the internal transcribed spacer regions (ITS1 and ITS2) of ribosomal DNA (rDNA), and the 5.85 rRNA gene, have been determined for 13 strains of dinoflagellates in order to analyze the phylo-genetic relationship. The DNA sequences contained considerable variation in the ITS regions, but little in the 5.85 rDNA. In addition, the ITS1 was more variable than the ITS2 in all species examined. The nucleotide length of this region varied from 519 bp to 596 bp depending on the taxa. The investigated taxa were divided into three large groups based on the ITS length, i. e., a group with short ITS region (A. fraterculus and Alexandrium sp.), a with ITS region group (P. micans, P. minimum and P. triestinum) and a with ITS region group (G. impudicum, C. polykrikoides, G. sanguineum, G. catenatum and H. triquetra). The relationship between nucleotide length of ITS1 and that of ITS2 was negative, whereas G+C content and nucleotide length showed positive correlation. In phylogenetic analyses producing NJ trees, the topology was similar cluster and clearly divided the taxa into three groups based on 5.8S rDNA that were similar to those based on morphological characteristics. In particular, G. impudicum was more closely related to G. catenatum than to C. polykrikoides using phylogenetic analysis. From this study, we chew that the length of ITS region contributes to discriminate Korean harmful algal species and ITS analysis is a useful method for resolving the systematic relationships of dinoflagellates.

• Journal of Aquaculture
• /
• v.6 no.3
• /
• pp.221-233
• /
• 1993

Cell size, DNA content, chromosome and PCR-based mitochondrial 12S rRNA gene analyses were conducted to obtain basic informations for genetic stock identification of spotted flounder (Verasper variegatus) from Yeocheun, Korea. The mean erythrocytic and nuclear volumes of spotted flounder were $211.10{\mu}m^3$ and $23.03{\mu}m^3$, respectively. The haploid DNA content of this species was 0.79 pg/cell which correspond to $46.5\%$ of carp and to $22.6\%$ of mammals. Spotted flounder had the 2n = 46 acrocentric chromosomes but no heteromorphic sex chromosomes was found. Mitochondrial DNA gene for 12S ribosomal RNA was amplified by polymerase chain reaction (PCR) and the PCR products were subjected to digestion with 15 restriction endonucleases. Restriction enzyme analyses revealed that Ava I, Mae II, Sma I and Xba I had one restriction site in the mitochondrial 12S rRNA gene segment of spotted flounder, while Mae I had two. Segments of 12S rRNA gene from mitochondria in spotted flounder were sequenced and compared with channel catfish and human as controls. The 12S rRNA gene of this species was more similar to that of channel catfish than to human's.

• Korean Journal of Microbiology
• /
• v.46 no.4
• /
• pp.366-374
• /
• 2010

Culture-dependent RFLP and culture-independent DGGE were employed to investigate the bacterial community associated with the marine sponge Spirastrella abata. A total of 164 bacterial strains associated with the sponge were cultivated using Zobell and Natural sea salt media. PCR amplicons of the 16S rDNA from the bacterial strains were digested with the restriction enzymes HaeIII and MspI, and then assigned into different groups according to their restriction patterns. The 16S rDNA sequences derived from RFLP patterns showed more than 95% similarities compared with known bacterial species, and the isolates belonged to four phyla, Proteobacteria (Alphaproteobacteria, Gammaproteobacteria), Actinobacteria, Firmicutes, and Bacteriodetes, of which Alphaproteobacteria was dominant. DGGE fingerprinting of 16S rDNAs amplified from the sponge- derived total gDNA showed five major DGGE bands, and their sequences showed more than 96% similarities compared with available sequences. The sequences derived from DGGE bands revealed high similarity with the uncultured bacterial clones. DGGE revealed that bacterial community consisted of four phyla, including Proteobacteria (Alphaproteobacteria, Gammaproteobacteria), Actinobacteria, Spirochetes, and Chloroflexi. Alphaproteobacteria, Gammaproteobacteria, and Actinobacteria were commonly found in bacteria associated with S. abata by both RFLP and DGGE methods; however, overall bacterial community in the sponge differed depending on the analysis methods.

• ALGAE
• /
• v.24 no.4
• /
• pp.205-212
• /
• 2009

Molecular genetic tools are widely used to learn more about the identical characterization of obscure microalgal strains. At the Korea Marine Microalgae Culture Center (KMMCC), the authors deduced the genetic relationship of 41 strains of the genus Tetraselmis by analysing a small subunit ribosomal DNA (18S rDNA) sequences. Forty-one strains were seperated into five groups, which showed over a 98-99% similarity to Tetraselmis striata or Tetraselmis sp. Tsbre. Also, 13 strains among them had an identical genotype to Tetraselmis striata while 5 strains had with Tetraselmis sp. Tsbre, respectively. The mean size of each strain generally showed the tendency of different variation according to the groups.

• Fisheries and Aquatic Sciences
• /
• v.10 no.4
• /
• pp.179-185
• /
• 2007

Understanding dietary habits is one of the most important factors in studying food webs and other ecological processes. Here we designed universal primers to amplify portions of the 18S and 28S rDNA sequences to examine gut contents using PCR techniques. The gut contents of sailfin sandfish (Arctoscopus japonicus) and pacific squid (Todarodes pacificus) were examined. In total, 11 families of prey were identified with 18S and 28S rDNA using the universal primers. The DNA sequence data indicated that the primer sets successfully amplified a wide spectrum of species and represented gut contents in a relatively convenient way. We found that information in the NCBI database was not yet sufficient to discriminate the species we isolated. In addition, technology for the separation of heterogeneous PCR products and better resolution and quantification protocols would help increase data accuracy.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 2000.10a
• /
• pp.109-117
• /
• 2000

Bacterial community structure composing enhanced biological phosphorus removal (EBPR) activated sludge was analyzed phylogenetically by cloning 165 rDNA after direct DNA extraction. Then, this result was compared with 165 rDNA sequences of randomly isolated bacterial species. The results clearly showed that there are no coincidence between the sequences retrieved directly from activated sludge and those of isolated strains, suggesting that many important bacteria are hidden in activated sludge because of the difficulty in isolation and culture of them.

• Animal Systematics, Evolution and Diversity
• /
• v.34 no.4
• /
• pp.194-198
• /
• 2018

The genus Prionchulus Cobb, 1916 represents a group of predaceous nematodes belonging to the family Mononchidae Chitwood, 1937, and is found worldwide. However, only five species have been reported thus far from Korea. Prionchulus oleksandri Winiszewska and Susulovsky, 2003 is reported for the first time from Korea, from sediments collected from the Nakdong River. This species is distinguished from other Prionchulus species by its truncated lip region with small cephalic papillae and refringens vaginae. In this study, morphological characters(detailed morphometrics) of P. oleksandri are described and illustrated using optical microscopy. DNA barcode sequence information (the D2-D3 region of 28S rDNA, 18S rDNA, and internal transcribed spacer rDNA) is also provided for the molecular identification of the species.

• International Journal of Oral Biology
• /
• v.46 no.3
• /
• pp.140-145
• /
• 2021

This study aimed to develop Lautropia mirabilis-specific quantitative real-time polymerase chain reaction (qPCR) primers based on the sequence of DNA-directed RNA polymerase subunit beta gene. The PrimerSelect program was used in designing of the qPCR primers, RTLam-F4 and RTLam-R3. The specificity of the qPCR primers were performed by conventional PCR with 37 strains of 37 oral bacterial species, including L. mirabilis. The sensitivity of the primers was determined by qPCR with the serial dilution of purified genomic DNA of L. mirabilis KCOM 3484, ranged from 4 ng to 4 fg. The data showed that the qPCR primers could detect only L. mirabilis strains and as little as 40 fg of genome DNA of L. mirabilis KCOM 3484. These results indicate that this qPCR primer pair (RTLam-F4/RTLam-R3) may be useful for species-specific detection of L. mirabilis in epidemiological studies of oral bacterial infectious diseases such as periodontal disease.

• International Journal of Oral Biology
• /
• v.44 no.3
• /
• pp.96-100
• /
• 2019

The purpose of this study was to develop Peptoniphilus mikwangii-specific quantitative real-time polymerase chain reaction (qPCR) primers based on the 16S ribosomal RNA (16S rDNA) gene. The specificity of the primers was determined by conventional PCR using 29 strains of 27 oral bacterial species including P. mikwangii. The sensitivity of the primers was determined by qPCR using the purified genomic DNA of P. mikwangii KCOM $1628^T$ (40 ng to 4 fg). The data showed that the qPCR primers (RTB134-F4/RTB134-R4) could detect P. mikwangii strains exclusively and as little as 40 fg of the genomic DNA of P. mikwangii KCOM $1628^T$. These results suggest that the developed qPCR primer pair can be useful for detecting P. mikwangii in epidemiological studies of oral bacterial infectious diseases.