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AbstractThe mitochondrial genome of Cybister brevis Aubé, 1838, is 16,198 bp long and includes 37 genes that are highly conserved in the family Dytiscidae. Phylogenetic analysis revealed that all genera in Dytiscidae, except Hydroporus and Oreodytes, are monophyletic. The Hydroporini tribe was found to be polyphyletic and closely associated with the Hygrotini, Bidessini, and Hyphydrini tribes. Dytiscinae was found to be a highly divergent polyphyletic group comprising three distinct clades. This study also revealed that C. brevis is closely related to Cybister japonicus and that the tribe Cybistrini diverged relatively early compared to other tribes in Hydroporinae. These findings are consistent with those of previous studies and provide new insights into the phylogeny of the Dytiscidae family, which has previously shown discrepancies between morphological characteristics and molecular data. The genome-level analyses conducted in this study serve as a valuable foundation for future investigations into the Dysticidae evolutionary history.

This study introduces one specimen each of the genera Gymnopilus, Marasmius, and Mycena as an unrecorded species found in the Hwasun Gotjawal and Jeju Gotjawal Provincial Park of the Hangyeong-Andeok terrain, South Korea. Morphological analyses of macroscopic and microscopic features, and molecular analysis of the nuclear ribosomal internal transcribed spacer region were conducted to identify the specimens. Our results indicated that the newly identified specimens were Gymnopilus dilepis, Marasmius tenuissimus, and Mycena seminau. Here, we describe these newly identified mushroom species and provide baseline data on their diversity in Gotjawal, South Korea.

Sargassum horneri (SH) and Ulva australis (UA) are marine waste resources that cause environmental and economic problems when entering or multiplying the coastal waters of Jeju Island. We analyzed their anti-diabetic efficacy to assess their reusability as functional additives. The alpha-glucosidase inhibitory activity of SH and UA extracts was confirmed, and the effect of UA extract was higher than that of SH. After the induction of insulin-resistant HepG2 cells, the effects of the two marine extracts on oxidative stress, intracellular glucose uptake, and glycogen content were compared to the positive control, metformin. Treatment of insulin-resistant HepG2 cells with SH and UA resulted in a concentration-dependent decrease in oxidative stress and increased intracellular glucose uptake and glycogen content. Moreover, SH and UA treatment upregulated the expression of IRS-1, AKT, and GLUT4, which are suppressed in insulin resistance, to a similar degree to metformin, and suppressed the expression of FoxO1, PEPCK involved in gluconeogenesis, and GSK-3β involved in glycogen metabolism. The oral administration of these extracts to rats with streptozotocin-induced diabetes led to a higher weight gain than that in the diabetic group. Insulin resistance and oral glucose tolerance are alleviated by the regulation of blood glucose. Thus, the SH and UA extracts may be used in the development of therapeutic agents or supplements to improve insulin resistance.

Eriocheir japonica inhabits rivers flowing into the East Sea, South Sea, and the coastal waters of Jeju-do in South Korea, Japan, and Sakhalin. The larvae migrate to freshwater, mature, and move to estuaries to spawn. Jeju-do has habitats that prevent the migration of aquatic organisms. Populations with low within-group genetic diversity experience increased extinction risk. Industrialization causes climate change and also creates species extinctions. The goal of this study was to investigate the genetic diversity of E. japonica inhabiting Andeok Valley to elucidate their genetic stability and encourage future conservation plans. E. japonica samples used for the study were from the Andeok Valley in South Korea. One walking leg was used for DNA extraction. DNA was amplified using polymerase chain reaction to sequence mitochondrial cytochrome c oxidase subunit 1 (CO1) and cytochrome b (CytB) genes. Haplotype and sequence diversity analyses were performed. Sequencing results for CO1 and CytB genes included 658 and 651 base pairs, respectively. The median network analysis showed that the population inhabiting Andeok Valley had a genetically simple phylogenetic structure. This region provides simple habitat conditions, preventing gene transfer. The probability of extinction of E. japonica that inhabits Andeok Valley is markedly high.

In Jeju-native Citrus, flavonoids are the main contributors to the various types of biological activity, such as antioxidant, antitumor, and anti-inflammatory activity. Thus, we developed simultaneous quantification methods for the analysis of ten bioactive flavonoids in Jeju Citrus fruits (Dangyuja, Gamja, Jigak, Sadugam, and Soyuja) harvested at six different time points using a high-performance liquid chromatography–diode array detector (HPLC-DAD). Separation was performed using a flow rate of 0.8 mL/min, a column temperature of 40 °C, a mobile phase buffer of 0.5% acetic acid, and a detection wavelength of 278 nm. The established analytical method showed good linearity (R2 ≥ 0.9997), precision (inter-day < 0.599%, intra-day < 0.055%), and accuracy (recoveries 92.30–108.80%). The HPLC–DAD method was subsequently applied to analyze flavonoids in Citrus samples. Overall, the quantification results indicated that the compositions and content of flavonoids differed for each Citrus species. The harvesting period also influenced the changes in flavonoid content within each Citrus species. The analytical results with chemometrics revealed that higher flavonoid levels in early-harvested Citrus were derived from the improved fruit size and reduced flavonoid synthesis during maturation. This study provides a practical and reliable method for the analysis of ten flavonoids that can be further utilized in the quality assessment of Jeju Citrus.

The complete mitochondrial genome of Tremoctopus violaceus was sequenced to analyze its organization and phylogenetic status within the order Octopoda. The mitochondrial genome of T. violaceus had a structure and organization similar to that of other Octopoda. The content of the nucleotides A, C, G, and T was 31.68 %, 7.71 %, 20.02 %, and 40.58 %, respectively. All protein-coding genes (PCG) began with the ATG codon, excluding ND4 and ATP6, which began with ATC and ATT, respectively, and terminated with TAG, TAA, TA, or T. Codons for isoleucine were the most used codons, whereas those for arginine were used the least. Two extra tRNAs, trnN and trnL, were found in the control region. These tRNAs have a D-armless structure. The control region had excess A + T content (83.16 %) and a stem-loop structure with two elements, which is reported for the first time in Octopoda by our study. Bayesian inference using 13 PCG revealed that Octopus and Octopodidae were polyphyletic, and that Tremoctopodidae diverged relatively earlier within Octopoda. The mitochondrial genome of T. violaceus and its characteristics may help to understand the evolutionary history of Octopoda and establish a marine biodiversity conservation strategy.

Current research highlights the use of natural products or phytochemicals as drugs and functional additives to treat obesity with few side effects. Sargassum horneri (SH) and Ulva australis (UA) are marine waste resources on Jeju Island, Republic of Korea. In this study, we analyzed their antioxidant and anti-obesity efficacies to confirm their potential as functional additives. We prepared SH and UA extracts using 80% ethanol and observed that free radical scavenging activity and total phenol content were high in SH extracts, and total flavonoid content was elevated in UA extracts. Additionally, 3T3-L1 cells were treated with SH and UA extracts, and the ability of the extracts to inhibit adipocyte differentiation was examined using Oil Red O staining and analysis of neutral fat content. We confirmed that the mRNA expression of the C/EBPα, PPARγ, and SREBP1c genes that act on adipocyte differentiation, and of FAS, a fatty acid synthase, was suppressed. Experiments in a mouse model of obesity showed that 12-week administration of a high-fat diet with 1% extract added to drinking water resulted in lower weight gain compared to the high-fat diet alone. These results suggest that SH and UA extracts have antioxidant properties and are effective in obesity prevention. Therefore, the two marine waste resources are potential functional additive candidates for preventing obesity.

Abstract The complete mitochondrial (mt) genome of Stereolepis doederleini was sequenced from a specimen collected in a commercial aquarium in Jeju Island. The sequence was 16,513 base pairs in length and, similar to other vertebrate mt genomes, included 37 mt genes and a noncoding control region; the gene order was identical to that of typical vertebrate mt genome. Mitochondrial genome sequences of 17 species from 12 families were used to reconstruct phylogenetic relationships within the order Pempheriformes. The phylogenetic trees were constructed with three methods (neighbor joining [NJ], maximum likelihood [ML], and Bayesian method) using 12 protein coding genes, but not ND6. In all phylogenetic trees, Pempheriformes were clustered into three strongly supported clades. Two Acropomatidae species (Synagrops japonicus in clade-Ⅰ and Doederleinia berycoides in clade-Ⅲ) were polyphyletic; S. japonicus was close to Lateolabracidae and was the sister of Glaucosomatidae + (Pempheridae/(Percophidae+Creediidae)), and D. berycoides was sister to Howellidae + Epigonidae. All phylogenetic trees supported a sister relationship between Creediidae and Percophidae in clade-Ⅰ. Glaucosomatidae formed a sister clade with Pempheridae. The relationships within clade-Ⅱ, which was composed of four families (Pentacerotidae, Polyprionidae, Banjosidae, and Bathyclupeidae), slightly differed between NJ/ML and BI tree topologies. In clade-Ⅲ, the relationships among Howellidae, Epigonidae, and Acropomatidae were strongly supported.

Magnolia flower buds are a source of herbal medicines with various active compounds. In this study, differences in the distribution and abundance of major essential oils, phenolic acids, and primary metabolites between white flower buds of Magnolia heptapeta and violet flower buds of Magnolia denudata var. purpurascens were characterised. A multivariate analysis revealed clear separation between the white and violet flower buds with respect to primary and secondary metabolites closely related to metabolic systems. White flower buds contained large amounts of monoterpene hydrocarbons (MH), phenolic acids, aromatic amino acids, and monosaccharides, related to the production of isoprenes, as MH precursors, and the activity of MH synthase. However, concentrations of β-myrcene, a major MH compound, were higher in violet flower buds than in white flower buds, possibly due to higher threonine levels and low acidic conditions induced by comparatively low levels of some organic acids. Moreover, levels of stress-related metabolites, such as oxygenated monoterpenes, proline, and glutamic acid, were higher in violet flower buds than in white flower buds. Our results support the feasibility of metabolic profiling for the identification of phytochemical differences and improve our understanding of the correlated biological pathways for primary and secondary metabolites.

The complete mitochondrial genome of the Jeju ground beetle Carabus smaragdinus monilifer was analyzed to determine its structure, morphology, and other characteristics. The 16,737-bp long mitochondrial genome consisted of 37 genes, including 13 protein-coding genes, two rRNAs, and 22 tRNAs. The order, encoding direction, and the initiation and termination codons of the 37 genes of C. smaragdinus monilifer were identical to those of other species in the family Carabidae. Phylogenetic analysis revealed that C. smaragdinus monilifer is clustered with Carabus lafossei. Herein, we have provided the complete mitochondrial genome sequence of C. smaragdinus monilifer to understand the phylogeny of Carabidae.

We determined the complete mitochondrial (mt) sequence of the Cocktail wrasse, Pteragogus flagellifer. The mt genome is 16,807 bp long and consists of 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and two noncoding regions. All its mt protein-coding genes begin with an ATG start codon except for CO1, which begins with GTG. The order of the mt genes is largely identical to that of typical vertebrates, although the position of the TMF-regulated nuclear protein (trnP) is unique among known Labridae gene arrangements. The phylogenetic tree of Labridae showed that P. flagellifer is relatively close to Pseudolabrus.

The mitochondrial genomes of Seriola quinqueradiata and S. lalandi were 16,539 and 16,535 base pairs long, respectively, whose organizations were similar to those of other bony fishes. The sequence similarity of two species was 93% in the mitochondrial whole genome. Between each coding gene, rRNA, and control region, the highest similarity was 98% in ATP8 and lowest similarity was 87% in the control region. Phylogenetic analysis of Carangidae mt 12 protein-coding genes showed that Seriola and Carangoides do not form a monophyletic genus.

The cytoprotective effect of quercitrin (QR) against oxidative stress induced cell damage by hydrogen peroxide (H2O2) in Chinese hamster lung fibroblast (V79-4) cells was investigated. QR evidenced a scavenging effect of 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide, hydroxyl radicals and on intracellular ROS, and thus prevented lipid peroxidation. As a result, QR reduced H2O2-induced cell death and apoptosis in V79-4 cells. Moreover, H2O2 induced the cleavage of caspase-3, -9, and poly-ADP-ribose polymerase (PARP) and a reduction in Bcl-xL levels, whereas pretreatment with QR significantly inhibited caspase-3, -9, and PARP cleavage and the reduction in Bcl-xL levels, and ultimately ameliorated H2O2-induced apoptosis. Taken together, these results indicate that the treatment of V79-4 cells with QR can block H2O2-induced apoptosis via the regulation of Bcl-xL. QR may be exploited as a biopreservative in food applications or as a health supplement to alleviate oxidative stress.

Osteoarthritis (OA) is a degenerative chronic disease that affects various tissues surrounding the joints, such as the subchondral bone and articular cartilage. The onset of OA is associated with uncontrolled catabolic and anabolic remodeling processes of the joints, including the cartilage and subchondral bone, to adapt to local biological and biochemical signals. In this study, we determined whether 70% ethanolic (EtOH) extract of Litsea japonica fruit (LJFE) had beneficial effects on the articular cartilage, including structural changes in the tibial subchondral bone, matrix degradation, and inflammatory responses, in OA by using a rat model of monosodium iodoacetate-induced OA. Our results showed that administration of LJFE increased the bone volume and cross-section thickness, but the mean number of objects per slice in this group was lower than that in the OA control (OAC) group. In addition, the LJFE decreased the expression of inflammatory cytokines. Compared to the OAC group, the group treated with high doses of LJFE (100 and 200 mg/kg) showed a more than 80% inhibition of the expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases. Our results suggest that LJFE can be used as a potential anti-osteoarthritic agent.