HDAC8 Deacetylates HIF-1α and Enhances Its Protein Stability to Promote Tumor Growth and Migration in Melanoma.

Melanoma is the most lethal type of skin cancer, and it causes more than 55,000 deaths annually. Although regional melanoma can be surgically removed, once melanoma metastasizes to other regions of the body, the survival rate drops dramatically. The current treatment options are chemotherapy, immunotherapy, and targeted therapy. However, the low response rate and the development of resistance necessitate the search for a novel therapeutic target in melanoma. Hypoxia-inducible factor-1 α (HIF-1α) is overexpressed in melanoma and plays a crucial role in driving malignant transformation in cancer cells. Here, we identified that histone deacetylase 8 (HDAC8) enhances the protein stability of HIF-1α. HDAC8 directly binds to and deacetylates HIF-1α, thereby promoting its protein stability. This, in turn, upregulates the transcriptional activity of HIF-1α and promotes the expressions of its target genes, such as hexokinase 2 (HK2) and glucose transporter 1 (GLUT1). The inhibition of HDAC8 suppresses the proliferation and metastasis of melanoma cells. Furthermore, HDAC8 is correlated with HIF1A expression and poor prognosis in samples from patients with melanoma. These findings uncover a novel epigenetic mechanism that maintains HIF-1α stability and implicates the potential of HDAC8 inhibitors for melanoma therapy.

Pathological Role of HDAC8: Cancer and Beyond.

Histone deacetylase 8 (HDAC8) is a class I HDAC that catalyzes the deacetylation of histone and non-histone proteins. As one of the best-characterized isoforms, numerous studies have identified interacting partners of HDAC8 pertaining to diverse molecular mechanisms. Consequently, deregulation and overexpression of HDAC8 give rise to diseases. HDAC8 is especially involved in various aspects of cancer progression, such as cancer cell proliferation, metastasis, immune evasion, and drug resistance. HDAC8 is also associated with the development of non-cancer diseases such as Cornelia de Lange Syndrome (CdLS), infectious diseases, cardiovascular diseases, pulmonary diseases, and myopathy. Therefore, HDAC8 is an attractive therapeutic target and various HDAC8 selective inhibitors (HDAC8is) have been developed. Here, we address the pathological function of HDAC8 in cancer and other diseases, as well as illustrate several HDAC8is that have shown anti-cancer effects.

Modulation of ecdysteroid and juvenile hormone signaling pathways by bisphenol analogues and polystyrene beads in the brackish water flea Diaphanosoma celebensis.

Owing to its high production and world-wide usage, plastic pollution is an increasing concern in marine environments. Plastic is decomposed into nano- and micro-sized debris, which negative affect reproduction and development in aquatic organisms. Bisphenol A (BPA), an additive of plastic, is released into the water column upon plastic degradation, and is known as a representative endocrine-disrupting chemical. However, the reproductive effects of plastics and bisphenols at the molecular level have not yet been explored in small marine crustaceans. In this study, we investigated the effects of polystyrene (PS) beads (0.05, 0.5, and 6 - µm) and bisphenol analogues (BPs; BPA, BPS, and BPF) on reproduction and development of small marine crustaceans. Effects on transcriptional changes in ecdysteroid and juvenile hormone (JH) signaling pathway-related genes were examined in the brackish water flea Diaphanosoma celebensis exposed to PS beads and BPs for 48 h. As results, BPs and PS beads delayed emergence time of first offspring, and increased fecundity in a concentration-dependent manner. BPs differentially modulated the expression of ecdysteroid and JH signaling pathway-related genes, indicating that BP analogs can disrupt endocrine systems via mechanisms different from those of BPA. PS beads was also changed the gene expression of both pathway, depending on their size and concentration. Our findings suggest that BP analogues and PS beads disrupt the endocrine system by modulating the hormonal pathways, affecting reproduction negatively. This study provides a better understanding of the molecular mode of action of BPs and PS beads in the reproduction of small crustaceans.

Validation of reference genes for quantitative real-time PCR in chemical exposed and at different age's brackish water flea Diaphanosoma celebensis.

Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), a primary approach for evaluating gene expression, requires an appropriate normalization strategy to confirm relative gene expression levels by comparison, and rule out variations that might occur in analytical procedures. The best option is to use a reference gene whose expression level is stable across various experimental conditions to compare the mRNA levels of a target gene. However, there is limited information on how the reference gene is differentially expressed at different ages (growth) in small invertebrates with notable changes such as molting. In this study, expression profiles of nine candidate reference genes from the brackish water flea, Diaphanosoma celebensis, were evaluated under diverse exposure to toxicants and according to growth. As a result, four different algorithms showed similar stabilities of genes for chemical exposures in the case of limited conditions using the same developmental stage (H2A was stable, whereas Act was fairly unstable in adults), while the results according to age showed a significantly different pattern in suite of candidate reference genes. This affected the results of genes EcRA and GST, which are involved in development and detoxification mechanisms, respectively. Our finding is the first step towards establishing a standardized real-time qRT-PCR analysis of this environmentally important invertebrate that has potential for aquatic ecotoxicology, particularly in estuarine environments.

Effects of polystyrene in the brackish water flea Diaphanosoma celebensis: Size-dependent acute toxicity, ingestion, egestion, and antioxidant response.

Owing to the increasing usage of plastics, their debris is continuously deposited in marine environments, resulting in deleterious effects on aquatic organisms. Although it is known that microplastics disturb the cellular redox status, knowledge of molecular in marine cladocerans is still lacking. In the present study, we investigated the acute toxicity of different-sized polystyrene (PS) beads (0.05, 0.5, and 6-µm diameter), ingestion and egestion patterns, their distribution in the tissues, and their effects on the antioxidant systems in the brackish water flea Diaphanosoma celebensis. All different-sized PS beads showed no mortality at the concentrations used in this study. After 48 h of exposure to PS beads of different sizes, all microbeads were retained in the digestive tract, but the retention time varied according to the bead size. In particular, the group that was exposed to 0.05-µm beads showed widely distributed fluorescence (e.g., in the embryo, and probably in lipid droplets as well as the digestive tract). The transcriptional level and enzyme activities of antioxidants were modulated depending on the size of the PS beads, and lipid peroxidation was induced in groups exposed to 0.05 and 0.5-µm beads. These findings suggest that the size of PS beads is an important factor for cellular toxicity, and can induce size-dependent oxidative stress in this species. This study provides a better understanding of the molecular modes of action of microplastics in marine zooplankton.

Combined effects of heavy metals (Cd, As, and Pb): Comparative study using conceptual models and the antioxidant responses in the brackish water flea.

The combined effect of toxic inducers has emerged as a challenging topic, particularly due to their inconsistent impacts on the environment. Using toxic unit (TU) based on LC50 value, we investigated the 48 h acute toxicities of the following combinations: Cd + As, Cd + Pb, As + Pb, and Cd + As + Pb, and binary and ternary combined effects were interpreted using concentration addition (CA) and independent action (IA) model. The molecular effects of these combinations were further examined on the basis of gene expression (four GST and two SOD isoforms) and antioxidant enzymes activity (SOD and GST). The CA-predicted LC50 was similar to the observed results, indicating that the CA model is more applicable for evaluating the combined effects of the metal mixtures. Synergistic effects (ΣTULC50 < 0.8) were observed for the mixtures As + Pb and Cd + Pb, while additive effects (0.8 < ΣTULC50 < 1.2) were observed for the mixtures Cd + As + Pb and Cd + As. No antagonistic effects were observed in this study. Molecular biomarkers for oxidative stress caused by metals, as well as traditional endpoints such as lethality, have shown a clear response in assessing the toxicity of binary and ternary mixtures. This study opens up a new avenue for the use of biomarkers to assess the combined effects of metals in aquatic environments.

Cloning and molecular characterization of estrogen-related receptor (ERR) and vitellogenin genes in the brackish water flea Diaphanosoma celebensis exposed to bisphenol A and its structural analogues.

Although it has previously been shown that bisphenol (BP) analogues may interfere with the normal hormonal regulation by acting as endocrine disrupting chemicals (EDCs), little information is available on effects of BP analogues in invertebrates, particularly on cladocerans. In the present study, we identified estrogen-related receptors (EER), vitellogenin (VTG), and VTG receptor (VtgR) from the brackish water flea Diaphanosoma celebensis, and examined the effects of BPA and the substitutes, BPF and BPS, in different sublethal concentrations. Gene expression varied with time well matched with brooding, suggesting that DcEER, DcVTG, and DcVtgR play a role in reproduction in D. celebensis. qRT-PCR analysis showed that BPA and its substitutes differently modulated mRNA expressions of DcEER, DcVTG, and DcVtgR, indicating that these compounds adversely affect the normal reproduction-related pathway. This study facilitates better understanding of the molecular mode of action of BP analogues on the reproductive system of D. celebensis.

Microbacterium protaetiae sp. nov., isolated from gut of larva of Protaetia brevitarsis seulensis.

A Gram-stain-positive, strictly aerobic, polar flagellated, short rod-shaped bacterium, designated DFW100M-13T, was isolated from gut of the larva of Protaetia brevitarsis seulensis collected from Wanju-gun, South Korea. The growth range of NaCl concentration was 0-3 % (w/v) (optimally 0 % (w/v)), the temperature range for growth was 10-40 °C (optimally 28-30 °C), and the pH range for growth was pH 6.0-9.0 (optimally pH 7.0-8.0). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain DFW100M-13T had a high sequence similarity to members of the genus Microbacterium, having the highest similarity with Microbacterium luticocti DSM 19459T (97.7 %), Microbacterium rhizosphaerae CHO1T (97.1 %), and Microbacterium immunditiarum SK 18T (97.0 %), and formed a distinct lineage with Microbacterium luticocti DSM 19459T within the genus Microbacterium. A phylogenetic tree based on house-keeping genes also showed the result similar to the 16S rRNA gene-based tree. The main respiratory quinone (>10 %) was MK-11, MK-12 and MK-10, and the predominant cellular fatty acids (>10 %) were iso-C16 : 0, anteiso-C17 : 0 and anteiso-C15 : 0. The polar lipids were composed of diphosphatidylglycerol, phosphatidylglycerol, an inidentified glycolipid and an unidnetified lipid. The peptidoglycan type was supposed to be the B2ß with amino acids d-alanine, d-glutamic acid, glycine, l-homoserine and d-ornithine. The genomic DNA G+C content was 68.0 mol%. Based on the polyphasic taxonomic data, strain DFW100M-13T is considered to represent a novel species, for which the name Microbacterium protaetiae sp. nov. is proposed. The type strain is DFW100M-13T (=KACC 19323T=NBRC 113120T).

Xylanimonas allomyrinae sp. nov. isolated from the gut of larva of Allomyrina dichotoma, reclassification of Xylanibacterium ulmi as Xylanimonas ulmi comb. nov. and Xylanimicrobium pachnodae as Xylanimonas pachnodae comb. nov., and emendation of the genus Xylanimonas.

A bacterium that was Gram-staining-positive, facultatively anaerobic, non-motile, rod- or filamentous-shaped, designated as strain 2JSPR-7T, was isolated from a gut of larvae of Allomyrina dichotoma which were raised at the National Institute of Agricultural Sciences, Wanju-gun, Republic of Korea. 2JSPR-7T had the highest 16S rRNA gene sequence similarity to Xylanibacterium ulmi XIL08T (98.1 %), Xylanimicrobium pachnodae NBRC 107786T (97.8 %) and Xylanimonas cellulosilytica DSM 15894T (97.5 %). Optimum growth conditions were at 28-30 °C, pH 7-8 and 0 % salt concentration. The cellular fatty acids mainly consisted of anteiso-C15 : 0, C14 : 0 and C16 : 0. The polar lipids were diphosphatidylglycerol, four unidentified phospholipids and two unidentified glycophospholipids. The major menaquinones were MK-8(H4) and MK-9(H4). The peptidoglycan structure was suggested to be the type A3α (A11.14) l-Lys-l-Ser with the presence of d-Ala, l-Ala, d-Glu, l-Ser and l-Lys. Whole cell sugars were rhamnose, ribose and glucose. The DNA G+C content was 72.7 mol%. We encountered difficulty in selecting a suitable genus to accommodate strain 2JSPR-7T from any of the genera Xylanimonas, Xylanimicrobium and Xylanibacterium based on the polyphasic approach including phylogenetic and phenotypic characterization. Therefore, it is proposed to combine the genera Xylanimicrobium and Xylanibacterium with the genus Xylanimonas considering the priority of publication and to classify strain 2JSPR-7T in the genus as Xylanimonas allomyrinae sp. nov. The type strain of the novel species is 2JSPR-7T (=KACC 19330T=NBRC 113052T). In addition, the description of the genus Xylanimonas is emended, and Xylanibacterium ulmi and Xylanimicrobium pachnodae are reclassified as Xylanimonas ulmi comb. nov. and Xylanimonas pachnodae comb. nov., respectively.

Gryllotalpicola protaetiae sp. nov., isolated from insect Protaetia brevitarsis seulensis, and emended descriptions of the genus Gryllotalpicola and the species Gryllotalpicola soli.

A bacterial strain, designated 2DFW10M-5T, was isolated from gut of the larva of Protaetia brevitarsis seulensis collected in the Republic of Korea. Cells of the strain were Gram-stain-positive, non-motile and rod-shaped. The strain grew at the range of 10-37 °C (optimum, 28-30 °C) and pH 4.0-8.0 (optimum, pH 7.0) and tolerated up to 1 % NaCl (w/v; optimum, 0 %) on Reasoner's 2A medium. It was catalase-positive and oxidase-negative. The 16S rRNA gene sequence of strain 2DFW10M-5T showed the highest similarity to Gryllotalpicola daejeonensis RU-04T (98.4 %), Gryllotalpicola soli KIS12-7T (98.2 %), Gryllotalpicola kribbensis PU-02T (97.5 %), Gryllotalpicola koreensis RU-16T (97.4 %) and Gryllotalpicola reticulitermitis TS-56T (97.2 %). The phylogenetic tree based on the 16S rRNA gene sequence revealed that strain 2DFW10M-5T fell into the radius of the genus Gryllotalpicola. The predominant fatty acid was ω-cyclohexyl-C17:0. The polar lipids of strain 2DFW10M-5T were diphosphatidylglycerol, phosphatidylglycerol, an unidentified phospholipid and two unidentified lipids. The detected isoprenoid quinones were MK-11 (61.0 %), MK-10 (33.7 %) and MK-12 (5.3 %). The peptidoglycan contained d- and l-alanine, d-glutamic acid, glycine, l-serine and d-lysine with l-lysine as the diamino acid. The DNA G+C content calculated from the genome sequence of strain 2DFW10M-5T was 69.2 mol%. On the basis of its genomic, phylogenetic and phenotypic properties and distinctiveness, strain 2DFW10M-5T represents a novel species of the genus Gryllotalpicola, for which the name Gryllotalpicola protaetiae sp. nov. is proposed. The type strain is 2DFW10M-5T (=KACC 19316T=NBRC 113049T).

Paraflavitalea soli gen. nov., sp. nov., isolated from greenhouse soil.

A bacterial strain designated 5GH32-13T was isolated from greenhouse soil in Yongin-city, Republic of Korea. Cells were Gram-stain-negative, strictly aerobic, motile rods of two different shapes. The strain was catalase-positive and oxidasenegative. Flexirubin-like pigments were not detected. ß-Carotene was produced. The strain grew in the range of 10-37°C (optimum of 28-30°C) and pH 6-8 (optimum of pH 7) and tolerated up to 1% (w/v) NaCl (optimum of 0%). According to the 16S rRNA gene sequence comparison, strain 5GH32-13T shared a sequence similarity of less than 96.0% with all validly named taxa, having the highest sequence similarity with Pseudoflavitalea soli KIS20-3T (95.8%), Pseudoflavitalea rhizosphaerae T16R-265T (95.4%), Flavitalea gansuensis JCN-23T (95.3%), Pseudobacter ginsenosidimutans Gsoil 221T (95.3%), and Flavitalea populi HY-50RT (95.2%). A phylogenetic tree showed that strain 5GH32-13T was not grouped consistently into any specific genus. Its only polyamine was homospermidine, and its major fatty acids (> 10% of total fatty acids) were iso-C15:0, iso-C17:0 3-OH, and iso-C15:1 G. The strain's only respiratory quinone was MK-7, and its polar lipids were phosphatidylethanolamine, one unidentified phospholipid, six unidentified aminolipids and four unidentified lipids. Its DNA G + C content was 47.5 mol%. The results from chemotaxonomic, phenotypic and phylogenetic analyses indicated that strain 5GH32-13T represents a novel species of a novel genus of the family Chitinophagaceae, and the name Paraflavitalea soli gen. nov., sp. nov. is proposed. The type strain is 5GH32-13T (= KACC 17331T = JCM 33061T).

Lactococcus allomyrinae sp. nov., isolated from gut of larvae of Allomyrina dichotoma.

Strain 1JSPR-7T, a facultatively anaerobic bacterium isolated from the gut of larvae of Allomyrina dichotoma raised in Wanju-gun, Republic of Korea, was characterized using a polyphasic approach. Comparative analysis of 16S rRNA gene and rpoB gene sequences showed that strain 1JSPR-7T fell within the genus Lactococcus, forming a compact cluster with the type strain of four subspecies of Lactococcus lactis and Lactococcus taiwanensis. The 16S rRNA gene sequence of strain 1JSPR-7T revealed the highest homology with L. lactissubsp. lactis JCM 5805T (97.3 %) and L. lactissubsp. hordniae NBRC 100931T (97.1 %), and the rpoB gene sequence showed the highest similarity to L. lactissubsp. cremoris DSM 20069T (91.4 %) and L. lactissubsp. tructae L105T (91.4 %). The average nucleotide identity and digital DNA-DNA hybridization values indicated that strain 1JSPR-7T was a novel species of the genus Lacococcus. The major fatty acids (>10 % of the total fatty acids) were summed feature 7 (unknown 18.846, C19 : 1ω6c and/or C19 : 0cyclo ω10c), C16 : 0 and C14 : 0, and the predominant menaquinone was MK-8 with MK-7 as a minor one. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, an unidentified phospholipid and three unidentified glycolipids with diphosphatidylglycerol as the major one. The cell-wall peptidoglycan was of the A4α type with an interpeptide bridge comprising l-Lys-d-Asp. The DNA G+C content based on the whole genome sequences was 37.4 mol%. Based on the data obtained, strain 1JSPR-7T represents a novel species of the genus Lactococcus, for which the name Lactococcusallomyrinae sp. nov. is proposed. The type strain is 1JSPR-7T (=KACC 19319T=NBRC 113068T).

Paenibacillus nuruki sp. nov., isolated from Nuruk, a Korean fermentation starter.

A Gram-stain-positive, rod-shaped, non-endospore-forming motile by means of peritrichous flagella, facultatively anaerobic bacterium designated TI45-13arT was isolated from Nuruk, a Korean traditional Makgeolli fermentation starter. It grew at 4-35°C (optimum, 28-30°C), pH 5.0-9.0 (optimum, pH 7.0) and NaCl concentrations up to 5% (w/v). Phylogenetic trees generated using 16S rRNA gene sequences revealed that strain TI45-13arT belonged to the genus Paenibacillus and showed the highest sequence similarities with Paenibacillus kyungheensis DCY88T (98.5%), Paenibacillus hordei RH-N24T (98.4%) and Paenibacillus nicotianae YIM h-19T (98.1%). The major fatty acid was anteiso-C15:0. The DNA G+C content was 39.0 mol%, and MK-7 was the predominant isoprenoid quinone. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified glycolipids, and one unidentified aminoglycolipid. The cell-wall peptidoglycan contained meso-diaminopimelic acid. On the basis of polyphasic taxonomy study, it was suggested that strain TI45-13arT represents a novel species within the genus Paenibacillus for which the name Paenibacillus nuruki sp. nov. is proposed. The type strain was TI45-13arT (= KACC 18728T = NBRC 112013T).

Weissella cryptocerci sp. nov., isolated from gut of the insect Cryptocercus kyebangensis.

A taxonomic study of a Gram-stain-positive, rod-shaped, non-motile, non-spore-forming, catalase-negative bacterium, isolated from the gut of an insect, Cryptocercus kyebangensis collected from the mountainous area of Seoraksan, Yangyang-gun, Republic of Korea, was conducted. Its 16S rRNA gene sequence showed high similarity values to Weissella ghanensis LMG 24286T (95.9 %), Weissella beninensis 2L24P13T (95.9 %), Weissella fabalis M75T (95.7 %) and Weissella fabaria 257T (95.7 %). The phylogenetic tree indicated that the novel organism formed a cluster with W. ghanensis LMG 24286T, W. beninensis 2L24P13T, W. fabalis M75T and W. fabaria 257T. The G+C content was 41.1 mol% on the basis of the whole-genome sequence. Polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, two unidentified aminophospholipids, one unidentified phospholipid and four unidentified lipids. The major cellular fatty acids were C18 : 1 ω9c, C16 : 0, C14 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and summed feature 8 (C16 : 1 ω7c and/or C16 : 1 ω6c). The cell-wall peptidoglycan was of A4α type with the interpeptide bridge of Gly-d-Glu. Based on these results, strain 26KH-42T could be classified as a novel species of the genus Weissella, for which the name Weissellacryptocerci sp. nov. is proposed. The type strain is 26KH-42T (=KACC 18423T=NBRC 113066T).

Protaetiibacter intestinalis gen. nov., of the family Microbacteriaceae, isolated from gut of Protaetia brevitarsis seulensis, reclassification of Lysinimonas kribbensis Jang et al. 2013 as Pseudolysinimonas kribbensis gen. nov., comb. nov. and emended description of the genus Lysinimonas Jang et al. 2013.

A Gram-stain-positive, strictly aerobic, rod-shaped, non-spore-forming, non-motile bacterium, designated strain 2DFWR-13T, was isolated from gut of the larva of Protaetia brevitarsis seulensis, in the Republic of Korea. Strain 2DFWR-13T showed high sequence similarities to Lysinimonas kribbensis MSL-13T (97.7 %), Homoserinibacter gongjuensis 5GH26-15T (97.2 %), Microbacterium deminutum KV-483T (97.1 %) and Herbiconiux ginsengi CGMCC 4.3491T (97.1 %). The predominant fatty acids (>10 % of the total fatty acids) were anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. The major menaquinones were MK-13 and MK-12. The peptidoglycan type was type B2 with the diagnostic amino acid d-DAB. The N-acyl type of the murein was glycolyl. The polar lipids consisted of diphosphatidylglycerol, an unidentified glycolipid and an unidentified lipid. The DNA G+C content was 71.5 mol%. Based on its phylogenetic distinctiveness and distinguishing phenotypic characteristics, we conclude that strain 2DFWR-13T represents a novel genus and species of the family Microbacteriaceae, for which the name Protaetiibacter intestinalis gen. nov., sp. nov. is proposed. The type strain of Protaetiibacter intestinalis is 2DFWR-13T (=KACC 19321T=NBRC 113050T). In addition, an emended description of the genus LysinimonasJang et al. 2013 and the reclassification of Lysinimonas kribbensisJang et al. 2013 as Pseudolysinimonas kribbensis gen. nov., comb. nov. are proposed.

Pulveribacter suum gen. nov., sp. nov., isolated from a pig farm dust collector.

An aerobic, Gram-stain-negative, polar-flagellated, rod-shaped bacterium, designated as SC2-7T, was isolated from the dust collector at a pig farm located in Wanju-gun, Jeollabuk-do, Republic of Korea. Growth occurred at 10-37 °C (optimum, 28-30 °C), pH 6.0-10.0 (optimum, 7.0-8.0) and in the presence of 0-3 % (w/v) NaCl (optimum, 0 %) on Reasoner's 2A medium. The phylogenetic tree based on the 16S rRNA gene sequences revealed that strain SC2-7T was a member of the family Comamonadaceae, forming a robust cluster with the genera Alicycliphilus, Oryzisolibacter and Melaminivora. The 16S rRNA gene sequences of strain SC2-7T showed the highest sequence similarities to Alicycliphilus denitrificans K601T (97.2 %), Oryzisolibacter propanilivorax EPL6T (97.0 %), Melaminivora alkalimesophila CY1T (96.9 %), Diaphorobacter polyhydroxybutyrativorans SL-205T (96.6 %), Diaphorobacter nitroreducens NA10BT (96.6 %) and Melaminivora jejuensis KBB12T (96.5 %). The tree based on the gyrA gene sequences also showed that strain SC2-7T fell into a phylogenetic position similar to that based on the 16S rRNA gene sequences. The polar lipids present were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, an unidentified aminolipid and an unidentified phospholipid. The predominant quinone was ubiquione-8. The major fatty acids were summed feature 3 (including C16 : 1ω6c and/or C16 : 1ω7c), C16 : 0 and summed feature 8 (including C18 : 1ω6c and/or C18 : 1ω7c). The genomic DNA G+C content was 69.1 mol%. On the basis of the phenotypic, phylogenetic and chemotaxonomic data presented here, strain SC2-7T represents a novel species of a new genus, for which the name Pulveribacter suum gen. nov., sp. nov., is proposed. The type strain of Pulveribacter suum is SC2-7T (=KACC 19309T=NBRC 113102T).

Acute toxicity of bisphenol A and its structural analogues and transcriptional modulation of the ecdysone-mediated pathway in the brackish water flea Diaphanosoma celebensis.

Bisphenol A (BPA) is a representative endocrine disrupting chemical (EDC) that has estrogenic effects in aquatic animals. In recent years, due to the continuing usage of BPA, its analogues have been developed as alternative substances to replace its use. The molting process is a pivotal point in the development and reproduction of crustaceans. However, studies of the effects of EDCs on molting in crustaceans at the molecular level are scarce. In the present study, we examined the acute toxicity of BPA and its analogues bisphenol F (BPF) and S (BPS) to the brackish water flea Diaphanosoma celebensis. We further identified four ecdysteroid pathway - related genes (cyp314a1, EcRA, EcRB, and USP) in D. celebensis, and investigated the transcriptional modulation of these genes during molting and after exposure to BPA and its analogues for 48 h. Sequencing and phylogenetic analyses revealed that these four genes are highly conserved among arthropods and may be involved in development and reproduction in the adult stage. The mRNA expression patterns of cyp314a1, EcRA and USP were matched with the molting cycle, suggesting that these genes play a role in the molting process in the adult stage in cladocerans. Following relative real-time polymerase chain reaction (RT-PCR) analyses, BPA and its analogues were found to modulate the expression of each of these four genes differently, indicating that these compounds can disrupt the normal endocrine system function of D. celebensis. This study improves our understanding of the molecular mode of action of BPA and its analogues in D. celebensis.

Paracoccus suum sp. nov., isolated from a pig farm dust collector.

A Gram-stain-negative, strictly aerobic, non-motile, non-spore-forming, coccoid- or short rod-shaped bacterial strain, designated SC2-6T, was isolated from a dust collector of a pig farm located in Wanju-gun, Jeollabuk-do, Republic of Korea. Strain SC2-6T grew within the ranges of 10-37 °C (28-30 °C, optimally), pH 6.0-10.0 (pH 7.0-8.0, optimally) and 0-3% NaCl (w/v). The 16S rRNA gene sequence similarity of strain SC2-6T showed the highest values to Paracoccus kondratievae GBT (96.3%), Paracoccus denitrificans DSM 413T (96.3%) and Paracoccus sanguinis 5503T (96.1%). The phylogenetic tree based on the 16S rRNA gene sequences revealed that strain SC2-6T belonged to the genus Paracoccus and clustered with Paracoccus pacificus F14T. The phylogenetic tree based on the rpoD gene sequences also demonstrated that strain SC2-6T fell into the clade of the genus Paracoccus. The DNA G+C content was 66.9 mol%. The major respiratory quinone was ubiquinone-10 and the major fatty acids (> 10% of the total fatty acids) were summed feature 8 (comprising C18 : 1 ω6c and/or C18 : 1 ω7c). The polar lipids were composed of diphosphatidylglycerol, phosphatidylcholine, an unidentified glycolipid, two unidentified aminolipids and two unidentified lipids. On the basis of phenotypic, phylogenetic and genomic data, strain SC2-6T was classified in the genus Paracoccus as a member of a novel species, for which the name Paracoccus suum sp. nov. is proposed. The type strain is SC2-6T (=KACC 19328T=NBRC 113110T).