• The Korean Journal of Malacology
• /
• v.30 no.3
• /
• pp.197-210
• /
• 2014

Single nucleotide polymorphisms (SNPs) are widely acknowledged as the marker of choice for many genetic and genomic applications because they show co-dominant inheritance, are highly abundant across genomes and are suitable for high-throughput genotyping. Here we evaluated the applicability of SNP markers developed from Crassostrea gigas and C. virginica expressed sequence tags (ESTs) in closely related Crassostrea and Ostrea species. A total of 213 putative interspecific level SNPs were identified from re-sequencing data in six amplicons, yielding on average of one interspecific level SNP per seven bp. High polymorphism levels were observed and the high success rate of transferability show that genic EST-derived SNP markers provide an efficient method for rapid marker development and SNP discovery in closely related oyster species. The six EST-SNP markers identified here will provide useful molecular tools for addressing questions in molecular ecology and evolution studies including for stock analysis (pedigree monitoring) in related oyster taxa.

• Animal Systematics, Evolution and Diversity
• /
• v.11 no.3
• /
• pp.329-334
• /
• 1995

The epicranial bony system of the six species of the family Cynoglossidae were examined based on the specimens collected from the coast of Korea from 1992 to 1994. They were divided into four groups by the morphological features of epicranial bony system as follow: 1. Paraplagusia japonica, 2. Cynoglossus joyneri and C. robustus, 3. C. semilaeuis and C. abbreuiatus, and 4. C. interruptus. Among them, P japonica showed the most derived character in the erisma and frontal elements of the epicranial bony system. And it was remarked that the number of proximal radials supporting erisma show much differences among the species. It is discussed that the morphological differences in the epicranial bony system are significant character for interspecific relationships in family Cynoglossidae.

• International Journal of Oral Biology
• /
• v.39 no.4
• /
• pp.215-220
• /
• 2014

Toothbrushes play an essential role in oral hygiene. However, they can be significant in microbial transmission and can increase the risk of infection, since they can serve as a reservoir for microorganisms in healthy, oral-diseased and medically ill adults. This study was conducted to evaluate toothbrush contamination in six toothbrushes donated from four people. Two participants each supplied two toothbrushes - one used in the bathroom and one used in the workplace. The other two people each donated two toothbrushes used in the workplace. Polymerase chain reaction was used to construct a 16S rRNA clone library. Sequences of cloned DNA were compared with those from the reference organisms provided by GenBank. A total 120 clones, representing 20 clones for each toothbrush, were analyzed. They are composed of six pylum, 46 genera and 79 species. The most dominant species were Streptococcus oralis, Streptococcus parasanguinis and Haemophilus parainfluenzae. Enterobacter and Escherichia were recovered from toothbrushes used domestically. Toothbrushes used in the workplace did not contain Enterobacteria.

• Journal of the Korean Wood Science and Technology
• /
• v.51 no.2
• /
• pp.81-97
• /
• 2023

The aim of this study were to evaluate tannin resorcinol formaldehyde (TRF) for the preparation of cross-laminated timbers (CLTs) made from fast-growing tree species and to analyze the physical and mechanical properties of CLTs. TRF copolymer resin was prepared by using the bark extracts of Swietenia mahagoni (L.) Jacq. It was observed that the TRF adhesive possessed less solid content (23.59%), high viscosity (11.35 poise), and high pH values (10.0) compared to the standard phenol resorcinol formaldehyde. The TRF adhesive was applied to produce CLTs with the addition of 15% tapioca and flour as an extender. The six-layered CLTs were produced from sengon (Falcataria moluccana Miq.), jabon [Anthocephalus cadamba (Roxb) Miq.], coconut (Cocos nucifera L.), and the combination of coconut-jabon and coconut-sengon wood. The analysis of variance revealed that the layer composition of CLT significantly affected the physical and mechanical properties of the beam. While the modulus of rupture met the standard, the moisture content and modulus of elasticity values did not fulfill JAS 1152-2007. All of the CLTs produced in this study demonstrated low formaldehyde emission, ranging from 0.001 mg/L to 0.003 mg/L, thereby satisfying the JAS 1152 for structural glue laminated timber.

• Genomics & Informatics
• /
• v.21 no.1
• /
• pp.10.1-10.6
• /
• 2023

The fishes of the Chiasmodontidae family, known as swallower fishes, are species adapted to live in deep seas. Several studies have shown the proximity of this family to Tetragonuridae and Amarsipidae. However, the phylogenetic position of this clade related to other Pelagiaria groups remains uncertain even when phylogenomic studies are employed. Since the low number of published mitogenomes, our study aimed to assemble six new mitochondrial genomes of Chiasmodontidae from database libraries to expand the discussion regarding the phylogeny of this group within Scombriformes. As expected, the composition and organization of mitogenomes were stable among the analyzed species, although we detected repetitive sequences in the D-loop of species of the genus Kali not seen in Chiasmodon, Dysalotus, and Pseudoscopelus. Our phylogeny incorporating 51 mitogenomes from several families of Scombriformes, including nine chiasmodontids, recovered interfamilial relationships well established in previous studies, including a clade containing Chiasmodontidae, Amarsipidae, and Tetragonuridae. However, phylogenetic relationships between larger clades remain unclear, with disagreements between different phylogenomic studies. We argue that such inconsistencies are not only due to biases and limitations in the data but mainly to complex biological events in the adaptive irradiation of Scombriformes after the Cretaceous-Paleogene extinction event.

• Journal of Microbiology
• /
• v.35 no.4
• /
• pp.253-258
• /
• 1997

The nuclear 18S ribosomal RNA genes of seven corticioid species were sequenced. These sequences were analyzed and compared with those of 24 other species of the order Aphyllophorales and phylogenetic trees were constructed using parsimonious methods. Phylogenetic analyses showed that two species among examined members of the Corticiaceae, Resinicium bicolor and Thanatephorus praticola, are located distantly from the remaining six species. The separation of R. bicolor seems to be kphylogenetically significant because it has very unique cystidia. The independent lineage of T. practicola suggests that it is also phylogenetically distinct because it has unusual features like the homobasidium producing secondary spores and the spetal ultrastructure of pore cap. Furthermore, Auriscalpium vulgare, Bondarzewia berkeleyi, and Heterobasidion annosum from different families of the Aphyllophorales proved to be closely related to the species of the Corticiaceae. They all have amyloid spores and grouped with Aleyrodiscus amorphus, which is a member of the Corticiaceae. The amyloidity of spores seems to be an improtant character throughout the order of the Aphyllophorales.

• Animal cells and systems
• /
• v.5 no.1
• /
• pp.17-23
• /
• 2001

Two new species of oribatid mites, Dicastribates tenuisetosus sp. nov, and Liacarus unjangensis sp. nov. are described from Korea. Dicastribates tenuisetosus sp. nov. is easily distinguishable from a single known species, D. heterotrichus (Mahunka, 1984) from Paraguay by the presence of 14 pairs of distallv attenuate notogastral setae, the smooth rostral and lamellar setae, the relatively short and distally attenuating interlamellar setae, the relatively short sensilli with distinctly clavated head, and presence of two and six setae on epimeral region III and genital plate. Liacarus unjangensis sp. nov. can be easily distinguished from most other known species by the very wide lamellae which cover dorsally whole prodorsum, the presence of equal sized inner and outer teeth of lamellar cusps and the minute rostral, lamellar and interlamellar setae.

• The Korean Journal of Malacology
• /
• v.11 no.1
• /
• pp.70-77
• /
• 1995

The purpose of this study is to determine the differences of the conchiolin layer, prismatic layer and nacreous layer deposited within the shell of the freshwater family Unionidae. shether they possess species-specific characteristics and differences of the microstructure of these layers, A Scanning electron microscopic obwervations were conducted on seven species. The results indicate that all species possess thin and homogeneous layers within the periostracum. The prismatic layers of these species were composed of ednsely packed prisms. The prismatic layers of the shell in six species were typical shape of prisms. especially Inio douglasiae and Lamprotual gottschei. But, in Unio douglasiae sinuolatus, it was irregular and oblique prism shape.The nacreous layer of weven unionids characterized by possession of three types by lamillae shape: thin and homogeneous on genus Anodonta(0.4 pm size of lamella), Unio(1.3pm) and Lamprotual (1.7pm), homogeneous in shape and irregular in size of lamillae in Lanceolaria(1.0 pm)and irregulat in shape and size in Solenaia(0.2-0.4 pm). The microstructure of the naceous layer may be useful as a taxonomic character at the generic level.

• ALGAE
• /
• v.27 no.2
• /
• pp.95-108
• /
• 2012

Using genetic sequencing (COI-5P, LSU, $rbc$L) to elucidate their phylogenetic positions and then morphological characters to distinguish each from existing species, three procumbent species, including two novel species, from warm temperate Northern Hemisphere waters are added to the recently resurrected genus $Halopeltis$ J. Agardh: $H.$ $adnata$ (Okamura) comb. nov. from Korea, $H.$ $pellucida$ sp. nov. from Bermuda and $H.$ $willisii$ sp. nov. from North Carolina, USA. Prior to these reports, the genus was confined to the Southern Hemisphere and tropical equatorial waters of the Northern Hemisphere although the latter records lack molecular confirmation. These three additional species join the six known species presently residing in $Halopeltis$.

• Journal of Species Research
• /
• v.5 no.3
• /
• pp.393-442
• /
• 2016

Twelve species of siphonostomatoid copepods mainly associated with marine invertebrates are recorded from Korean waters. Nine species are new to science: Arctopontius minutus n. sp., A. adelphus n. sp, and Dyspontius alatus n. sp. in the family Artotrogidae; Asterocheres horridus n. sp., A. cuspis n. sp., A. quadridens n. sp., Scottocheres mipoensis n. sp., Asteropontoides acutirostris n. sp. and Callomyzon macrocephalus n. gen. n. sp. in the family Asterocheridae. The new genus Callomyzon is distinguished from other genera in the family by having six setae on the third endopodal segment of leg 3, four spines and three setae on the third exopodal segment of leg 4 and three setae on the third endopodal segment of leg 4. Three new records of Korea, Asterocheres lilljeborgi Boeck, 1859 and A. simulans (T. Scott, 1898) in the Asterocheridae, and Parartotrogus arcticus T. and A. Scott, 1901 in the Cancerillidae are redescribed as the circum-Arctic species.