Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 15 de 15
Filter
1.
Headache ; 64(2): 195-210, 2024 02.
Article in English | MEDLINE | ID: mdl-38288634

ABSTRACT

OBJECTIVE: To characterize the circadian features of the trigeminal ganglion in a mouse model of headache. BACKGROUND: Several headache disorders, such as migraine and cluster headache, are known to exhibit distinct circadian rhythms of attacks. The circadian basis for these rhythmic pain responses, however, remains poorly understood. METHODS: We examined trigeminal ganglion ex vivo and single-cell cultures from Per2::LucSV reporter mice and performed immunohistochemistry. Circadian behavior and transcriptomics were investigated using a novel combination of trigeminovascular and circadian models: a nitroglycerin mouse headache model with mechanical thresholds measured every 6 h, and trigeminal ganglion RNA sequencing measured every 4 h for 24 h. Finally, we performed pharmacogenomic analysis of gene targets for migraine, cluster headache, and trigeminal neuralgia treatments as well as trigeminal ganglion neuropeptides; this information was cross-referenced with our cycling genes from RNA sequencing data to identify potential targets for chronotherapy. RESULTS: The trigeminal ganglion demonstrates strong circadian rhythms in both ex vivo and single-cell cultures, with core circadian proteins found in both neuronal and non-neuronal cells. Using our novel behavioral model, we showed that nitroglycerin-treated mice display circadian rhythms of pain sensitivity which were abolished in arrhythmic Per1/2 double knockout mice. Furthermore, RNA-sequencing analysis of the trigeminal ganglion revealed 466 genes that displayed circadian oscillations in the control group, including core clock genes and clock-regulated pain neurotransmitters. In the nitroglycerin group, we observed a profound circadian reprogramming of gene expression, as 331 of circadian genes in the control group lost rhythm and another 584 genes gained rhythm. Finally, pharmacogenetics analysis identified 10 genes in our trigeminal ganglion circadian transcriptome that encode target proteins of current medications used to treat migraine, cluster headache, or trigeminal neuralgia. CONCLUSION: Our study unveiled robust circadian rhythms in the trigeminal ganglion at the behavioral, transcriptomic, and pharmacogenetic levels. These results support a fundamental role of the clock in pain pathophysiology. PLAIN LANGUAGE SUMMARY: Several headache diseases, such as migraine and cluster headache, have headaches that occur at the same time each day. We learned that the trigeminal ganglion, an important pain structure in several headache diseases, has a 24-hour cycle that might be related to this daily cycle of headaches. Our genetic analysis suggests that some medications may be more effective in treating migraine and cluster headache when taken at specific times of the day.


Subject(s)
Cluster Headache , Migraine Disorders , Trigeminal Neuralgia , Mice , Animals , Trigeminal Ganglion , Transcriptome , Trigeminal Neuralgia/genetics , Nitroglycerin , Headache , Gene Expression Profiling , Pain , Circadian Rhythm/genetics , Mice, Knockout
2.
Chronobiol Int ; 40(1): 4-12, 2023 01.
Article in English | MEDLINE | ID: mdl-34521283

ABSTRACT

The circadian clock plays a fundamental role in physiology. In particular, the heart is a target organ where the clock orchestrates various aspects of cardiac function. At the molecular level, the clock machinery governs daily rhythms of gene expression. Such circadian regulation is in tune with the dynamic nature of heart structure and function, and provides the foundation for chronotherapeutic applications in cardiovascular diseases. In comparison, a regulatory role of the clock in cardiac protein degradation is poorly documented. Sarcomere is the structural and functional unit responsible for cardiac muscle contraction, and sarcomere components are closely regulated by protein folding and proteolysis. Emerging evidence supports a role of the circadian clock in governing sarcomere integrity and function. Particularly, recent studies uncovered a circadian regulation of a core sarcomere component TCAP. It is possible that circadian regulation of the cardiac muscle protein turnover is a key regulatory mechanism underlying cardiac remodeling in response to physiological and environmental stimuli. While the detailed regulatory mechanisms and the molecular links to cardiac (patho)physiology remain to be further studied, therapeutic strategies targeting circadian control in the heart may markedly enhance intervention outcomes against cardiovascular disease.


Subject(s)
Cardiovascular Diseases , Circadian Clocks , Humans , Circadian Rhythm/genetics , Proteolysis , Myocardium/metabolism , Circadian Clocks/physiology
3.
Clocks Sleep ; 3(3): 351-365, 2021 Jun 22.
Article in English | MEDLINE | ID: mdl-34206497

ABSTRACT

Dysregulated circadian functions contribute to various diseases, including cardiovascular disease. Much progress has been made on chronotherapeutic applications of drugs against cardiovascular disease (CVD); however, the direct effects of various medications on the circadian system are not well characterized. We previously conducted high-throughput chemical screening for clock modulators and identified an off-patent anti-arrhythmic drug, moricizine, as a clock-period lengthening compound. In Per2:LucSV reporter fibroblast cells, we showed that under both dexamethasone and forskolin synchronization, moricizine was able to increase the circadian period length, with greater effects seen with the former. Titration studies revealed a dose-dependent effect of moricizine to lengthen the period. In contrast, flecainide, another Class I anti-arrhythmic, showed no effects on circadian reporter rhythms. Real-time qPCR analysis in fibroblast cells treated with moricizine revealed significant circadian time- and/or treatment-dependent expression changes in core clock genes, consistent with the above period-lengthening effects. Several clock-controlled cardiac channel genes also displayed altered expression patterns. Using tissue explant culture, we showed that moricizine was able to significantly prolong the period length of circadian reporter rhythms in atrial ex vivo cultures. Using wild-type C57BL/6J mice, moricizine treatment was found to promote sleep, alter circadian gene expression in the heart, and show a slight trend of increasing free-running periods. Together, these observations demonstrate novel clock-modulating activities of moricizine, particularly the period-lengthening effects on cellular oscillators, which may have clinical relevance against heart diseases.

4.
Br J Pharmacol ; 177(21): 4845-4850, 2020 11.
Article in English | MEDLINE | ID: mdl-32442317

ABSTRACT

Coronavirus disease 2019 (COVID-19), the disease resulting from infection by a novel coronavirus, SARS-Cov2, has rapidly spread since November 2019 leading to a global pandemic. SARS-Cov2 has infected over four million people and caused over 290,000 deaths worldwide. Although most cases are mild, a subset of patients develop a severe and atypical presentation of acute respiratory distress syndrome (ARDS) that is characterised by a cytokine release storm (CRS). Paradoxically, treatment with anti-inflammatory agents and immune regulators has been associated with worsening of ARDS. We hypothesize that the intrinsic circadian clock of the lung and the immune system may regulate individual components of CRS, and thus, chronotherapy may be used to effectively manage ARDS in COVID-19 patients. LINKED ARTICLES: This article is part of a themed issue on The Pharmacology of COVID-19. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.21/issuetoc.


Subject(s)
Coronavirus Infections/drug therapy , Pneumonia, Viral/drug therapy , Respiratory Distress Syndrome/drug therapy , Animals , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/adverse effects , Betacoronavirus/immunology , Betacoronavirus/isolation & purification , COVID-19 , Circadian Rhythm/physiology , Coronavirus Infections/immunology , Coronavirus Infections/virology , Cytokine Release Syndrome/drug therapy , Cytokine Release Syndrome/virology , Drug Chronotherapy , Humans , Pandemics , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Respiratory Distress Syndrome/immunology , Respiratory Distress Syndrome/virology , SARS-CoV-2 , COVID-19 Drug Treatment
5.
Acta Physiol (Oxf) ; 225(1): e13161, 2019 01.
Article in English | MEDLINE | ID: mdl-29969187

ABSTRACT

Circadian rhythms of physiology are the keys to health and fitness, as dysregulation, by genetic mutations or environmental factors, increases disease risk and aggravates progression. Molecular and physiological studies have shed important light on an intrinsic clock that drives circadian rhythms and serves essential roles in metabolic homoeostasis, organ physiology and brain functions. One exciting new area in circadian research is pain, including headache and neuropathic pain for which new mechanistic insights have recently emerged. For example, cluster headache is an intermittent pain disorder with an exceedingly precise circadian timing, and preliminary evidence is emerging linking several circadian components (eg, Clock and Nr1d1) with the disease. In this review, we first discuss the broad metabolic and physiological relevance of the circadian timing system. We then provide a detailed review of the circadian relevance in pain disease and physiology, including cluster headache, migraine, hypnic headache and neuropathic pain. Finally, we describe potential therapeutic implications, including existing pain medicines and novel clock-modulating compounds. The physiological basis for the circadian rhythms in pain is an exciting new area of research with profound basic and translational impact.


Subject(s)
Circadian Rhythm , Headache/etiology , Neuralgia/etiology , Chronotherapy , Headache/metabolism , Humans , Migraine Disorders/etiology , Migraine Disorders/metabolism , Neuralgia/metabolism
6.
Cell Syst ; 6(3): 314-328.e2, 2018 Mar 28.
Article in English | MEDLINE | ID: mdl-29525205

ABSTRACT

Cancer chronotherapy, treatment at specific times during circadian rhythms, endeavors to optimize anti-tumor effects and to lower toxicity. However, comprehensive characterization of clock genes and their clinical relevance in cancer is lacking. We systematically characterized the alterations of clock genes across 32 cancer types by analyzing data from The Cancer Genome Atlas, Cancer Therapeutics Response Portal, and The Genomics of Drug Sensitivity in Cancer databases. Expression alterations of clock genes are associated with key oncogenic pathways, patient survival, tumor stage, and subtype in multiple cancer types. Correlations between expression of clock genes and of other genes in the genome were altered in cancerous versus normal tissues. We identified interactions between clock genes and clinically actionable genes by analyzing co-expression, protein-protein interaction, and chromatin immunoprecipitation sequencing data and also found that clock gene expression is correlated to anti-cancer drug sensitivity in cancer cell lines. Our study provides a comprehensive analysis of the circadian clock across different cancer types and highlights potential clinical utility of cancer chronotherapy.


Subject(s)
Chronotherapy/methods , Circadian Clocks/genetics , Neoplasms/genetics , Circadian Clocks/physiology , Circadian Rhythm , Genomics , Humans , Pharmacogenetics/methods
7.
Annu Rev Pharmacol Toxicol ; 58: 231-252, 2018 01 06.
Article in English | MEDLINE | ID: mdl-28968186

ABSTRACT

Circadian timekeeping systems drive oscillatory gene expression to regulate essential cellular and physiological processes. When the systems are perturbed, pathological consequences ensue and disease risks rise. A growing number of small-molecule modulators have been reported to target circadian systems. Such small molecules, identified via high-throughput screening or derivatized from known scaffolds, have shown promise as drug candidates to improve biological timing and physiological outputs in disease models. In this review, we first briefly describe the circadian system, including the core oscillator and the cellular networks. Research progress on clock-modulating small molecules is presented, focusing on development strategies and biological efficacies. We highlight the therapeutic potential of small molecules in clock-related pathologies, including jet lag and shiftwork; various chronic diseases, particularly metabolic disease; and aging. Emerging opportunities to identify and exploit clock modulators as novel therapeutic agents are discussed.


Subject(s)
Circadian Clocks/drug effects , Circadian Rhythm/drug effects , Small Molecule Libraries/pharmacology , Small Molecule Libraries/therapeutic use , Aging/drug effects , Animals , Chronic Disease/drug therapy , Humans , Metabolic Diseases/drug therapy
8.
Medicine (Baltimore) ; 96(45): e8629, 2017 Nov.
Article in English | MEDLINE | ID: mdl-29137098

ABSTRACT

RATIONALE: Cancer-related neuropathic pain often responds poorly to standard pain treatments. Scrambler therapy has relieved refractory chronic pain in several uncontrolled clinical trials. PATIENT CONCERNS: An 11-year-old female patient was suffering from left groin and medial thigh pain after irradiation to the knee. The girl was diagnosed with precursor B-cell lymphoblastic leukemia 2 years ago. Extramedullary relapse of leukemia developed 1 month ago and pain had started. She was treated with oral medications, but she was continuously complaining of severe pain. DIAGNOSIS: Neuropathic pain caused by obturator nerve involvement in leukemia. INTERVENTION: Scrambler therapy. OUTCOME: Pain reduction. LESSONS: Scrambler therapy is noninvasive, is not associated with any complications, causes minimal discomfort during treatment, and is very effective in a pediatric patient with cancer-related neuropathic pain.


Subject(s)
Cancer Pain/etiology , Cancer Pain/therapy , Electric Stimulation Therapy , Leukemia/complications , Neuralgia/etiology , Neuralgia/therapy , Cancer Pain/diagnostic imaging , Child , Female , Groin/diagnostic imaging , Humans , Leg/diagnostic imaging , Leukemia/diagnostic imaging , Leukemia/therapy , Neuralgia/diagnostic imaging
9.
Article in English | MEDLINE | ID: mdl-25852644

ABSTRACT

Modernization of human society parallels an epidemic of metabolic disorders including obesity. Apart from excess caloric intake, a 24/7 lifestyle poses another important challenge to our metabolic health. Recent research under both laboratory and epidemiological settings has indicated that abnormal temporal organization of sleep and wakeful activities including food intake is a significant risk factor for metabolic disease. The circadian clock system is our intrinsic biological timer that regulates internal rhythms such as the sleep/wake cycle and also responses to external stimuli including light and food. Initially thought to be mainly involved in the timing of sleep, the clock, and/or clock genes may also play a role in sleep architecture and homeostasis. Importantly, an extensive body of evidence has firmly established a master regulatory role of the clock in energy balance. Together, a close relationship between well-timed circadian/sleep cycles and metabolic health is emerging. Exploiting this functional connection, an important holistic strategy toward curbing the epidemic of metabolic disorders (e.g., obesity) involves corrective measures on the circadian clock and sleep. In addition to behavioral and environmental interventions including meal timing and light control, pharmacological agents targeting sleep and circadian clocks promise convenient and effective applications. Recent studies, for example, have reported small molecules targeting specific clock components and displaying robust beneficial effects on sleep and metabolism. Furthermore, a group of clock-amplitude-enhancing small molecules (CEMs) identified via high-throughput chemical screens are of particular interest for future in vivo studies of their metabolic and sleep efficacies. Elucidating the functional relationship between clock, sleep, and metabolism will also have far-reaching implications for various chronic human diseases and aging.

10.
Nature ; 485(7396): 62-8, 2012 Mar 29.
Article in English | MEDLINE | ID: mdl-22460951

ABSTRACT

Synchronizing rhythms of behaviour and metabolic processes is important for cardiovascular health and preventing metabolic diseases. The nuclear receptors REV-ERB-α and REV-ERB-ß have an integral role in regulating the expression of core clock proteins driving rhythms in activity and metabolism. Here we describe the identification of potent synthetic REV-ERB agonists with in vivo activity. Administration of synthetic REV-ERB ligands alters circadian behaviour and the circadian pattern of core clock gene expression in the hypothalami of mice. The circadian pattern of expression of an array of metabolic genes in the liver, skeletal muscle and adipose tissue was also altered, resulting in increased energy expenditure. Treatment of diet-induced obese mice with a REV-ERB agonist decreased obesity by reducing fat mass and markedly improving dyslipidaemia and hyperglycaemia. These results indicate that synthetic REV-ERB ligands that pharmacologically target the circadian rhythm may be beneficial in the treatment of sleep disorders as well as metabolic diseases.


Subject(s)
Circadian Rhythm/drug effects , Circadian Rhythm/physiology , Energy Metabolism/drug effects , Nuclear Receptor Subfamily 1, Group D, Member 1/antagonists & inhibitors , Pyrrolidines/pharmacology , Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors , Repressor Proteins/antagonists & inhibitors , Thiophenes/pharmacology , Adipose Tissue/drug effects , Adipose Tissue/metabolism , Animals , Biological Clocks/drug effects , Biological Clocks/genetics , Biological Clocks/physiology , Circadian Rhythm/genetics , Disease Models, Animal , HEK293 Cells , Humans , Hypothalamus/drug effects , Hypothalamus/metabolism , Liver/drug effects , Liver/metabolism , Metabolome/drug effects , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Muscle, Skeletal/drug effects , Muscle, Skeletal/metabolism , Nuclear Receptor Subfamily 1, Group D, Member 1/metabolism , Obesity/chemically induced , Obesity/drug therapy , Obesity/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Repressor Proteins/metabolism
11.
J Microbiol ; 49(3): 502-7, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21717340

ABSTRACT

A bacterial strain, designated GR24-5(T), was isolated from soil cultivated with Korean ginseng. Cells were Gram-negative, strictly aerobic, catalase- and oxidase-positive, non-spore-forming motile rods. Based on the 16S rRNA gene sequence, strain GR24-5(T) could be assigned to the family Alcaligenaceae. Strain GR24-5(T) showed the highest sequence similarities with Parapusillimonas granuli Ch07(T) (97.1%), Pusillimonas noertemannii BN9(T) (96.9%), Pigmentiphaga kullae DSM 13608(T) (96.5%), and Castellaniella defragrans 54Pin(T) (96.3%). Strain GR24-5(T) demonstrated a low DNA-DNA relatedness (23%) with P. granuli Ch07(T). The major respiratory quinone is ubiquinone 8 (Q-8) and the major fatty acids are C(16:0), C(17:0) cyclo, and summed feature 1 (C(14:0) 3-OH/iso-C(16:1) I/C(12:0) aide). Putrescine, spermidine, and 2-hydroxyputrescine are the major polyamines. The major polar lipids are phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, di-phosphatidylglycerol, and an unknown aminophospholipid. Polar lipid patterns of strain GR24-5(T) were unique in having a large amount of phosphatidylmethylethanolamine. Based on phylogenetic analysis and physiological and biochemical characteristics, strain GR245(T) represents a novel genus and species, for which the name Paralcaligenes ureilyticus gen. nov., sp. nov. is proposed. The type strain of P. aralcaligenes ureilyticus is GR24-5(T) (=KACC 13888 =DSM 24591(T)).


Subject(s)
Agriculture , Alcaligenaceae/classification , Alcaligenaceae/isolation & purification , Panax/growth & development , Soil Microbiology , Alcaligenaceae/genetics , Alcaligenaceae/physiology , Bacterial Typing Techniques , DNA, Bacterial/analysis , DNA, Bacterial/genetics , Genes, rRNA , Phenotype , Phylogeny , RNA, Ribosomal, 16S/genetics , Republic of Korea , Sequence Analysis, DNA , Species Specificity
12.
Int J Syst Evol Microbiol ; 59(Pt 6): 1282-5, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19502302

ABSTRACT

The taxonomic status of a yellow- to light orange-coloured strain isolated from soil of a Korean ginseng field was established based on a polyphasic investigation. The novel isolate, strain GR10-1(T), was an obligately aerobic, Gram-staining-negative, non-motile, flexirubin-pigment-producing, short rod-shaped bacterium. The strain grew optimally at 28-30 degrees C, at pH 7.0 and in the presence of 0-1 % NaCl. Phylogenetic analyses based on 16S rRNA gene sequences demonstrated that the new isolate showed the highest sequence similarities with Niabella aurantiaca R2A15-11(T) (95.1 %) and Niabella soli JS13-8(T) (94.6 %). The DNA G+C content of strain GR10-1(T) was 43 mol%. It contained iso-C(15 : 1) G (36.4 %) and iso-C(15 : 0) (32.8 %) as the major fatty acids (>10 %) and MK-7 as the major isoprenoid quinone. On the basis of evidence from our polyphasic taxonomic study, it was concluded that strain GR10-1(T) should be classified within a novel species of the genus Niabella, for which the name Niabella ginsengisoli sp. nov. is proposed. The type strain is GR10-1(T) (=KACC 13021(T) =JCM 15444(T)).


Subject(s)
Bacteroidetes/classification , Panax , Soil Microbiology , Bacterial Typing Techniques , Bacteroidetes/genetics , Bacteroidetes/isolation & purification , Bacteroidetes/physiology , Base Composition , DNA, Bacterial/analysis , DNA, Ribosomal/analysis , Fatty Acids/analysis , Molecular Sequence Data , Phenotype , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Species Specificity
13.
Int J Syst Evol Microbiol ; 57(Pt 3): 646-649, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17329800

ABSTRACT

A Gram-negative, strictly aerobic, non-spore-forming bacterium, motile by means of single polar flagellum and rod-shaped, designated strain GR12-1(T), was isolated from soil of a ginseng field in Yeongju region, Korea. Phylogenetic analysis based on 16S rRNA gene sequences indicated that this strain is related to members of the genus Pseudoxanthomonas, showing sequence similarity values ranged from 92.3 to 96.2 %. This organism grew at 5-33 degrees C, with optimum growth at 28 degrees C. Strain GR12-1(T) grew optimally in the presence of 0-2 % NaCl. The whole-cell fatty acid profile included iso-C(15 : 0), iso-C(17 : 1)omega9c, iso-C(16 : 0), iso-C(11 : 0) 3-OH and iso-C(17 : 0) as major components. The only isoprenoid quinone was ubiquinone 8 (Q-8). The DNA G+C content was 63.4 mol%. On the basis of phenotypic, genetic and phylogenetic data, strain GR12-1(T) should be classified as a member of a novel species of the genus Pseudoxanthomonas, for which the name Pseudoxanthomonas yeongjuensis sp. nov. is proposed, with strain GR12-1(T) (=KACC 11580(T)=DSM 18204(T)) as the type strain.


Subject(s)
Panax/microbiology , Soil Microbiology , Xanthomonadaceae/classification , DNA, Bacterial/genetics , DNA, Ribosomal , Korea , Molecular Sequence Data , Phylogeny , RNA, Ribosomal, 16S/genetics , Xanthomonadaceae/genetics , Xanthomonadaceae/isolation & purification
14.
Int J Syst Evol Microbiol ; 57(Pt 1): 122-125, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17220453

ABSTRACT

A polyphasic study was carried out to clarify the taxonomic position of a Gram-negative bacterium isolated from soil cultivated with Korean ginseng in the Eumseong region of Korea. The novel strain, GP25-8(T), grew optimally at pH 6-7, 28 degrees C and 0-1 % NaCl (w/v). The major fatty acids were C(18 : 1)omega7c, summed feature 3 (C(16 : 1)omega7c/C(15 : 0) iso 2-OH) and C(16 : 0) (together representing 71.2 % of the total). The 16S rRNA gene sequence similarities between strain GP25-8(T) and members of the genus Burkholderia ranged from 94.7 to 97.4 %, indicating that this novel strain was phylogenetically related to members of that genus. The novel strain showed the highest sequence similarities to Burkholderia caryophylli ATCC 25418(T) (97.4 %) and Burkholderia phenazinium LMG 2247(T) (97.2 %); the levels of DNA-DNA hybridization with these strains were 28 and 12 %, respectively. These results support the conclusion that strain GP25-8(T) represents a novel species within the genus Burkholderia, for which the name Burkholderia soli sp. nov. is proposed. The type strain is GP25-8(T) (=KACC 11589(T)=DSM 18235(T)).


Subject(s)
Burkholderia/classification , Panax/growth & development , Soil Microbiology , Agriculture , Bacterial Typing Techniques , Burkholderia/chemistry , Burkholderia/genetics , Burkholderia/isolation & purification , DNA, Bacterial/analysis , DNA, Ribosomal/analysis , Fatty Acids/analysis , Genes, rRNA , Korea , Molecular Sequence Data , Nucleic Acid Hybridization , Phenotype , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
15.
Int J Syst Evol Microbiol ; 56(Pt 8): 1777-1782, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16902007

ABSTRACT

Two novel strains, GR20-10(T) and GR20-13(T), were isolated from soil using R2A medium. The soil sample was collected from a field in the Yeongju region of Korea that was cultivated with Korean ginseng. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains formed a cluster with several uncultured bacterial clones and with Flexibacter filiformis, Flexibacter sancti, Flexibacter japonensis, Cytophaga arvensicola and Flavobacterium ferrugineum (recently reclassified as Terrimonas ferruginea) in the phylum Bacteroidetes. The level of 16S rRNA gene sequence similarity between the two novel strains was 98.9 %. Isolates GR20-10(T) and GR20-13(T) showed the highest sequence similarities to Flexibacter japonensis IFO 16041(T) (91.8 and 91.9 %, respectively) and T. ferruginea ATCC 13524(T) (90.4 and 90.6 %, respectively). The whole-cell fatty acid profiles of the two isolates were similar and their major fatty acids were 15 : 0 iso, 17 : 0 iso 3-OH and 15 : 1 iso G. The major isoprenoid quinone of both strains was MK-7. The G+C contents of GR20-10(T) and GR20-13(T) were 45.8 and 44.3 mol%, respectively. DNA-DNA hybridization (57 % DNA-DNA hybridization value) and phenotypic data indicated that strains GR20-10(T) and GR20-13(T) each belong to a separate species. On the basis of phenotypic and phylogenetic data and genomic distinctiveness, strains GR20-10(T) and GR20-13(T) represent two novel species in a novel genus in the phylum Bacteroidetes; the names Niastella koreensis gen. nov., sp. nov. (the type species; type strain GR20-10(T)=KACC 11465(T)=DSM 17620(T)) and Niastella yeongjuensis sp. nov. (type strain GR20-13(T)=KACC 11466(T)=DSM 17621(T)) are proposed.


Subject(s)
Bacteroidetes/classification , Soil Microbiology , Agriculture , Bacteroidetes/chemistry , Bacteroidetes/genetics , Bacteroidetes/isolation & purification , Base Composition , Cyanoacrylates/analysis , DNA, Bacterial/genetics , Fatty Acids/analysis , Korea , Molecular Sequence Data , Nucleic Acid Hybridization , Panax , Phylogeny , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Sequence Homology, Nucleic Acid , Species Specificity
SELECTION OF CITATIONS
SEARCH DETAIL