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1.
Neuropsychopharmacology ; 48(12): 1789-1797, 2023 11.
Article in English | MEDLINE | ID: mdl-37264172

ABSTRACT

The circadian system influences many different biological processes, including memory performance. While the suprachiasmatic nucleus (SCN) functions as the brain's central pacemaker, downstream "satellite clocks" may also regulate local functions based on the time of day. Within the dorsal hippocampus (DH), for example, local molecular oscillations may contribute to time-of-day effects on memory. Here, we used the hippocampus-dependent Object Location Memory task to determine how memory is regulated across the day/night cycle in mice. First, we systematically determined which phase of memory (acquisition, consolidation, or retrieval) is modulated across the 24 h day. We found that mice show better long-term memory performance during the day than at night, an effect that was specifically attributed to diurnal changes in memory consolidation, as neither memory acquisition nor memory retrieval fluctuated across the day/night cycle. Using RNA-sequencing we identified the circadian clock gene Period1 (Per1) as a key mechanism capable of supporting this diurnal fluctuation in memory consolidation, as learning-induced Per1 oscillates in tandem with memory performance in the hippocampus. We then show that local knockdown of Per1 within the DH impairs spatial memory without affecting either the circadian rhythm or sleep behavior. Thus, Per1 may independently function within the DH to regulate memory in addition to its known role in regulating the circadian system within the SCN. Per1 may therefore exert local diurnal control over memory consolidation within the DH.


Subject(s)
Hippocampus , Memory Consolidation , Animals , Mice , Circadian Rhythm/physiology , Hippocampus/metabolism , Memory Consolidation/physiology , Period Circadian Proteins/genetics , Spatial Memory , Suprachiasmatic Nucleus/metabolism
2.
J Biol Chem ; 299(7): 104871, 2023 07.
Article in English | MEDLINE | ID: mdl-37247760

ABSTRACT

Malaria causes >600 thousand fatalities each year, with most cases attributed to the human-infectious Plasmodium falciparum species. Many rodent-infectious Plasmodium species, like Plasmodium berghei and Plasmodium yoelii, have been used as model species that can expedite studies of this pathogen. P. yoelii is an especially good model for investigating the mosquito and liver stages of development because key attributes closely resemble those of P. falciparum. Because of its importance, in 2002 the 17XNL strain of P. yoelii was the first rodent malaria parasite to be sequenced. Although this was a breakthrough effort, the assembly consisted of >5000 contiguous sequences that adversely impacted the annotated gene models. While other rodent malaria parasite genomes have been sequenced and annotated since then, including the related P. yoelii 17X strain, the 17XNL strain has not. As a result, genomic data for 17X has become the de facto reference genome for the 17XNL strain while leaving open questions surrounding possible differences between the 17XNL and 17X genomes. In this work, we present a high-quality genome assembly for P. yoelii 17XNL using PacBio DNA sequencing. In addition, we use Nanopore and Illumina RNA sequencing of mixed blood stages to create complete gene models that include coding sequences, alternate isoforms, and UTR designations. A comparison of the 17X and this new 17XNL assembly revealed biologically meaningful differences between the strains due to the presence of coding sequence variants. Taken together, our work provides a new genomic framework for studies with this commonly used rodent malaria model species.


Subject(s)
Malaria , Parasites , Plasmodium yoelii , Animals , Humans , Plasmodium yoelii/genetics , Rodentia , Malaria/parasitology , Liver
3.
bioRxiv ; 2023 Jan 07.
Article in English | MEDLINE | ID: mdl-36711553

ABSTRACT

Malaria causes over 200 million infections and over 600 thousand fatalities each year, with most cases attributed to a human-infectious Plasmodium species, Plasmodium falciparum . Many rodent-infectious Plasmodium species, like Plasmodium berghei, Plasmodium chabaudi , and Plasmodium yoelii , have been used as genetically tractable model species that can expedite studies of this pathogen. In particular, P. yoelii is an especially good model for investigating the mosquito and liver stages of parasite development because key attributes closely resemble those of P. falciparum . Because of its importance to malaria research, in 2002 the 17XNL strain of P. yoelii was the first rodent malaria parasite to be sequenced. While sequencing and assembling this genome was a breakthrough effort, the final assembly consisted of >5000 contiguous sequences that impacted the creation of annotated gene models. While other important rodent malaria parasite genomes have been sequenced and annotated since then, including the related P. yoelii 17X strain, the 17XNL strain has not. As a result, genomic data for 17X has become the de facto reference genome for the 17XNL strain while leaving open questions surrounding possible differences between the 17XNL and 17X genomes. In this work, we present a high-quality genome assembly for P. yoelii 17XNL using HiFi PacBio long-read DNA sequencing. In addition, we use Nanopore long-read direct RNA-seq and Illumina short-read sequencing of mixed blood stages to create complete gene models that include not only coding sequences but also alternate transcript isoforms, and 5' and 3' UTR designations. A comparison of the 17X and this new 17XNL assembly revealed biologically meaningful differences between the strains due to the presence of coding sequence variants. Taken together, our work provides a new genomic and gene expression framework for studies with this commonly used rodent malaria model species.

4.
Redox Biol ; 59: 102571, 2023 02.
Article in English | MEDLINE | ID: mdl-36516721

ABSTRACT

Macrophages play a pivotal role in mediating inflammation and subsequent resolution of inflammation. The availability of selenium as a micronutrient and the subsequent biosynthesis of selenoproteins, containing the 21st amino acid selenocysteine (Sec), are important for the physiological functions of macrophages. Selenoproteins regulate the redox tone in macrophages during inflammation, the early onset of which involves oxidative burst of reactive oxygen and nitrogen species. SELENOW is a highly expressed selenoprotein in bone marrow-derived macrophages (BMDMs). Beyond its described general role as a thiol and peroxide reductase and as an interacting partner for 14-3-3 proteins, its cellular functions, particularly in macrophages, remain largely unknown. In this study, we utilized Selenow knock-out (KO) murine bone marrow-derived macrophages (BMDMs) to address the role of SELENOW in inflammation following stimulation with bacterial endotoxin lipopolysaccharide (LPS). RNAseq-based temporal analyses of expression of selenoproteins and the Sec incorporation machinery genes suggested no major differences in the selenium utilization pathway in the Selenow KO BMDMs compared to their wild-type counterparts. However, selective enrichment of oxidative stress-related selenoproteins and increased ROS in Selenow-/- BMDMs indicated anomalies in redox homeostasis associated with hierarchical expression of selenoproteins. Selenow-/- BMDMs also exhibited reduced expression of arginase-1, a key enzyme associated with anti-inflammatory (M2) phenotype necessary to resolve inflammation, along with a significant decrease in efferocytosis of neutrophils that triggers pathways of resolution. Parallel targeted metabolomics analysis also confirmed an impairment in arginine metabolism in Selenow-/- BMDMs. Furthermore, Selenow-/- BMDMs lacked the ability to enhance characteristic glycolytic metabolism during inflammation. Instead, these macrophages atypically relied on oxidative phosphorylation for energy production when glucose was used as an energy source. These findings suggest that SELENOW expression in macrophages may have important implications on cellular redox processes and bioenergetics during inflammation and its resolution.


Subject(s)
Selenium , Selenoprotein W , Mice , Animals , Selenoprotein W/genetics , Selenoprotein W/metabolism , Selenium/metabolism , Selenoproteins/genetics , Selenoproteins/metabolism , Macrophages/metabolism , Oxidation-Reduction , Inflammation/genetics
5.
PLoS Pathog ; 18(10): e1010926, 2022 10.
Article in English | MEDLINE | ID: mdl-36306287

ABSTRACT

The emergence of Plasmodium falciparum parasite resistance to dihydroartemisinin + piperaquine (PPQ) in Southeast Asia threatens plans to increase the global use of this first-line antimalarial combination. High-level PPQ resistance appears to be mediated primarily by novel mutations in the P. falciparum chloroquine resistance transporter (PfCRT), which enhance parasite survival at high PPQ concentrations in vitro and increase the risk of dihydroartemisinin + PPQ treatment failure in patients. Using isogenic Dd2 parasites expressing contemporary pfcrt alleles with differential in vitro PPQ susceptibilities, we herein characterize the molecular and physiological adaptations that define PPQ resistance in vitro. Using drug uptake and cellular heme fractionation assays we report that the F145I, M343L, and G353V PfCRT mutations differentially impact PPQ and chloroquine efflux. These mutations also modulate proteolytic degradation of host hemoglobin and the chemical inactivation of reactive heme species. Peptidomic analyses reveal significantly higher accumulation of putative hemoglobin-derived peptides in the PPQ-resistant mutant PfCRT isoforms compared to parental PPQ-sensitive Dd2. Joint transcriptomic and metabolomic profiling of late trophozoites from PPQ-resistant or -sensitive isogenic lines reveals differential expression of genes involved in protein translation and cellular metabolism. PPQ-resistant parasites also show increased susceptibility to an inhibitor of the P. falciparum M17 aminopeptidase that operates on short globin-derived peptides. These results reveal unique physiological changes caused by the gain of PPQ resistance and highlight the potential therapeutic value of targeting peptide metabolism in P. falciparum.


Subject(s)
Antimalarials , Artemisinins , Malaria, Falciparum , Parasites , Animals , Humans , Plasmodium falciparum/genetics , Plasmodium falciparum/metabolism , Chloroquine/pharmacology , Chloroquine/metabolism , Parasites/metabolism , Protozoan Proteins/metabolism , Drug Resistance/genetics , Malaria, Falciparum/drug therapy , Malaria, Falciparum/genetics , Malaria, Falciparum/parasitology , Antimalarials/metabolism , Membrane Transport Proteins/genetics , Membrane Transport Proteins/metabolism , Artemisinins/pharmacology , Mutation , Hemoglobins/metabolism , Heme/metabolism
6.
Nutrients ; 14(8)2022 Apr 08.
Article in English | MEDLINE | ID: mdl-35458125

ABSTRACT

Vitamin A (VA) deficiency and diarrheal diseases are both serious public health issues worldwide. VA deficiency is associated with impaired intestinal barrier function and increased risk of mucosal infection-related mortality. The bioactive form of VA, retinoic acid, is a well-known regulator of mucosal integrity. Using Citrobacter rodentium-infected mice as a model for diarrheal diseases in humans, previous studies showed that VA-deficient (VAD) mice failed to clear C. rodentium as compared to their VA-sufficient (VAS) counterparts. However, the distinct intestinal gene responses that are dependent on the host's VA status still need to be discovered. The mRNAs extracted from the small intestine (SI) and the colon were sequenced and analyzed on three levels: differential gene expression, enrichment, and co-expression. C. rodentium infection interacted differentially with VA status to alter colon gene expression. Novel functional categories downregulated by this pathogen were identified, highlighted by genes related to the metabolism of VA, vitamin D, and ion transport, including improper upregulation of Cl- secretion and disrupted HCO3- metabolism. Our results suggest that derangement of micronutrient metabolism and ion transport, together with the compromised immune responses in VAD hosts, may be responsible for the higher mortality to C. rodentium under conditions of inadequate VA.


Subject(s)
Enterobacteriaceae Infections , Vitamin A Deficiency , Animals , Citrobacter rodentium , Colon/metabolism , Diarrhea/complications , Intestinal Mucosa/metabolism , Intestine, Small/metabolism , Mice , Mice, Inbred C57BL , Vitamin A/metabolism , Vitamin A Deficiency/complications
9.
J Hazard Mater ; 420: 126665, 2021 10 15.
Article in English | MEDLINE | ID: mdl-34351284

ABSTRACT

Microbial communities are crucial to the effectiveness and stability of bioremediation systems treating acid mine drainage (AMD); however, little research has addressed how they correlate to system performance under changing environmental conditions. In this study, 16S rRNA gene sequencing and quantitative PCR (qPCR) were used to characterize microbial communities within different substrate combinations of crab shell (CS) and spent mushroom compost (SMC) and their association with chemical performance in pilot-scale vertical flow ponds (VFPs) treating high risk AMD in central Pennsylvania over 643 days of operation. As compared to a control containing SMC, VFPs containing CS sustained higher alkalinity, higher sulfate-reducing rates, and more thorough metals removal (>90% for Fe and Al, >50% for Mn and Zn). Correspondingly, CS VFPs supported the growth of microorganisms in key functional groups at increasing abundance and diversity over time, especially more diverse sulfate-reducing bacteria. Through changing seasonal and operational conditions over almost two years, the relative abundance of the core phyla shifted in all reactors, but the smallest changes in functional gene copies were observed in VFPs containing CS. These results suggest that the high diversity and stability of microbial communities associated with CS are consistent with effective AMD treatment.


Subject(s)
Brachyura , Microbiota , Acids , Animals , Brachyura/genetics , Mining , RNA, Ribosomal, 16S/genetics
10.
Front Microbiol ; 12: 704168, 2021.
Article in English | MEDLINE | ID: mdl-34220789

ABSTRACT

Chloracidobacterium is the first and until now the sole genus in the phylum Acidobacteriota (formerly Acidobacteria) whose members perform chlorophyll-dependent phototrophy (i.e., chlorophototrophy). An axenic isolate of Chloracidobacterium thermophilum (strain B T ) was previously obtained by using the inferred genome sequence from an enrichment culture and diel metatranscriptomic profiling analyses in situ to direct adjustments to the growth medium and incubation conditions, and thereby a defined growth medium for Chloracidobacterium thermophilum was developed. These advances allowed eight additional strains of Chloracidobacterium spp. to be isolated from microbial mat samples collected from Mushroom Spring, Yellowstone National Park, United States, at temperatures of 41, 52, and 60°C; an axenic strain was also isolated from Rupite hot spring in Bulgaria. All isolates are obligately photoheterotrophic, microaerophilic, non-motile, thermophilic, rod-shaped bacteria. Chloracidobacterium spp. synthesize multiple types of (bacterio-)chlorophylls and have type-1 reaction centers like those of green sulfur bacteria. Light harvesting is accomplished by the bacteriochlorophyll a-binding, Fenna-Matthews-Olson protein and chlorosomes containing bacteriochlorophyll c. Their genomes are approximately 3.7 Mbp in size and comprise two circular chromosomes with sizes of approximately 2.7 Mbp and 1.0 Mbp. Comparative genomic studies and phenotypic properties indicate that the nine isolates represent three species within the genus Chloracidobacterium. In addition to C. thermophilum, the microbial mats at Mushroom Spring contain a second species, tentatively named Chloracidobacterium aggregatum, which grows as aggregates in liquid cultures. The Bulgarian isolate, tentatively named Chloracidobacterium validum, will be proposed as the type species of the genus, Chloracidobacterium. Additionally, Chloracidobacterium will be proposed as the type genus of a new family, Chloracidobacteriaceae, within the order Blastocatellales, the class Blastocatellia, and the phylum Acidobacteriota.

11.
J Nutr Biochem ; 98: 108814, 2021 12.
Article in English | MEDLINE | ID: mdl-34242724

ABSTRACT

Vitamin A (VA) deficiency remains prevalent in resource limited areas. Using Citrobacter rodentium infection in mice as a model for diarrheal diseases, previous reports showed reduced pathogen clearance and survival due to vitamin A deficient (VAD) status. To characterize the impact of preexisting VA deficiency on gene expression patterns in the intestines, and to discover novel target genes in VA-related biological pathways, VA deficiency in mice were induced by diet. Total mRNAs were extracted from small intestine (SI) and colon, and sequenced. Differentially Expressed Gene (DEG), Gene Ontology (GO) enrichment, and co-expression network analyses were performed. DEGs compared between VAS and VAD groups detected 49 SI and 94 colon genes. By GO information, SI DEGs were significantly enriched in categories relevant to retinoid metabolic process, molecule binding, and immune function. Three co-expression modules showed significant correlation with VA status in SI; these modules contained four known retinoic acid targets. In addition, other SI genes of interest (e.g., Mbl2, Cxcl14, and Nr0b2) in these modules were suggested as new candidate genes regulated by VA. Furthermore, our analysis showed that markers of two cell types in SI, mast cells and Tuft cells, were significantly altered by VA status. In colon, "cell division" was the only enriched category and was negatively associated with VA. Thus, these data suggested that SI and colon have distinct networks under the regulation of dietary VA, and that preexisting VA deficiency could have a significant impact on the host response to a variety of disease conditions.


Subject(s)
Colon/metabolism , Intestine, Small/metabolism , RNA-Seq/methods , Vitamin A Deficiency/genetics , Animals , Citrobacter rodentium , Enterobacteriaceae Infections/genetics , Enterobacteriaceae Infections/microbiology , Gene Expression Profiling/methods , Gene Ontology , Mice , Mice, Inbred C57BL , RNA, Messenger/genetics , Transcriptome , Tretinoin/metabolism , Vitamin A/genetics , Vitamin A/metabolism
12.
Front Behav Neurosci ; 15: 678102, 2021.
Article in English | MEDLINE | ID: mdl-34149372

ABSTRACT

Deaths related to opioid use have skyrocketed in the United States, leading to a public health epidemic. Research has shown that both biological (genes) and environmental (stress) precursors are linked to opioid use. In particular, stress during adolescence-a critical period of frontal lobe development-influences the likelihood of abusing drugs. However, little is known about the biological mechanisms through which adolescent stress leads to long-term risk of opioid use, or whether genetic background moderates this response. Male and female C57BL/6J and BALB/cJ mice were exposed to chronic variable social stress (CVSS) or control conditions throughout adolescence and then tested for morphine locomotor sensitization or morphine consumption in adulthood. To examine possible mechanisms that underlie stress-induced changes in morphine behaviors, we assessed physiological changes in response to acute stress exposure and prefrontal cortex (PFC) miRNA gene expression. Adolescent stress did not influence morphine sensitization or consumption in BALB/cJ animals, and there was limited evidence of stress effects in female C57BL/6J mice. In contrast, male C57BL/6J mice exposed to adolescent CVSS had blunted morphine sensitization compared to control animals; no differences were observed in the acute locomotor response to morphine administration or morphine consumption. Physiologically, C57BL/6J mice exposed to CVSS had an attenuated corticosterone recovery following an acute stressor and downregulation of twelve miRNA in the PFC compared to control mice. The specificity of the effects for C57BL/6J vs. BALB/cJ mice provides evidence of a gene-environment interaction influencing opioid behaviors. However, this conclusion is dampened by limited locomotor sensitization observed in BALB/cJ mice. It remains possible that results may differ to other doses of morphine or other behavioral responses. Long-term differences in stress reactivity or miRNA expression in C57BL/6J mice suggests two possible biological mechanisms to evaluate in future research.

13.
J Thorac Oncol ; 16(4): 665-676, 2021 04.
Article in English | MEDLINE | ID: mdl-33485960

ABSTRACT

INTRODUCTION: In CheckMate 227 (NCT02477826), patients with treatment-naive stage IV or recurrent NSCLC and 1% or greater tumor programmed death ligand 1 expression had significantly improved overall survival with nivolumab plus ipilimumab versus chemotherapy. We present the patient-reported outcomes (PROs). METHODS: Patients (N = 1189) were randomized to nivolumab plus ipilimumab, nivolumab, or chemotherapy. PROs were exploratory. Changes in Lung Cancer Symptom Scale (LCSS) average symptom burden index, LCSS 3-item global index, EQ-5D visual analog scale (VAS), and EQ-5D utility index were analyzed descriptively. Mixed-effect model repeated measures and time-to-first deterioration and improvement analyses were conducted. RESULTS: PRO completion rates were generally greater than 80%. On-treatment improvements from baseline in LCSS measures of symptom burden and global health status with nivolumab plus ipilimumab generally met or exceeded the minimal important difference (smallest clinically meaningful change) from weeks 24 and 30, respectively; improvements with chemotherapy generally remained below the minimal important difference. Mean on-treatment EQ-5D VAS scores for both treatments approached the U.K. population norm at week 24, remaining so throughout the treatment period. Mixed-effect model repeated measures analyses revealed numerically greater improvements from baseline with nivolumab plus ipilimumab versus chemotherapy across LCSS average symptom burden index and 3-item global index, and EQ-5D VAS and utility index. Nivolumab plus ipilimumab had delayed time-to-first deterioration (hazard ratio [95% confidence interval] 0.74 [0.56 to 0.98]) and a trend for more rapid time-to-first improvement (1.24 [0.98 to 1.59]) versus chemotherapy. CONCLUSIONS: Nivolumab plus ipilimumab revealed delayed deterioration and numerical improvement in symptoms and health-related quality of life versus chemotherapy in patients with advanced NSCLC and 1% or greater programmed death ligand 1 expression.


Subject(s)
Lung Neoplasms , Nivolumab , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , B7-H1 Antigen/therapeutic use , Humans , Ipilimumab/therapeutic use , Lung Neoplasms/drug therapy , Neoplasm Recurrence, Local/drug therapy , Nivolumab/therapeutic use , Patient Reported Outcome Measures , Quality of Life
14.
Microbiol Resour Announc ; 10(1)2021 Jan 07.
Article in English | MEDLINE | ID: mdl-33414309

ABSTRACT

We report the complete 4,352,172-bp genome sequence of Mycobacterium orygis strain 51145 assembled into a single circular chromosome. Comparative genomic analyses with other lineages of the Mycobacterium tuberculosis complex can provide insights into the biology, evolution, and epidemiology of this important group of pathogenic mycobacteria.

15.
Addict Biol ; 26(1): e12859, 2021 01.
Article in English | MEDLINE | ID: mdl-31782218

ABSTRACT

Nicotine use remains highly prevalent with tobacco and e-cigarette products consumed worldwide. However, increasing evidence of transgenerational epigenetic inheritance suggests that nicotine use may alter behavior and neurobiology in subsequent generations. We tested the effects of chronic paternal nicotine exposure in C57BL6/J mice on fear conditioning in F1 and F2 offspring, as well as conditioned fear extinction and spontaneous recovery, nicotine self-administration, hippocampal cholinergic functioning, RNA expression, and DNA methylation in F1 offspring. Paternal nicotine exposure was associated with enhanced contextual and cued fear conditioning and spontaneous recovery of extinguished fear memories. Further, nicotine reinforcement was reduced in nicotine-sired mice, as assessed in a self-administration paradigm. These behavioral phenotypes were coupled with altered response to nicotine, upregulated hippocampal nicotinic acetylcholine receptor binding, reduced evoked hippocampal cholinergic currents, and altered methylation and expression of hippocampal genes related to neural development and plasticity. Gene expression analysis suggests multigenerational effects on broader gene networks potentially involved in neuroplasticity and mental disorders. The changes in fear conditioning similarly suggest phenotypes analogous to anxiety disorders similar to post-traumatic stress.


Subject(s)
Fear/drug effects , Hippocampus/metabolism , Memory/drug effects , Nicotine/pharmacology , Paternal Exposure/adverse effects , Animals , Conditioning, Psychological/drug effects , Cues , Extinction, Psychological , Female , Male , Mice , Mice, Inbred C57BL , Up-Regulation/drug effects
16.
Genes (Basel) ; 13(1)2021 12 23.
Article in English | MEDLINE | ID: mdl-35052372

ABSTRACT

Ovarian cancer is the most lethal gynecological malignancy in women. Metformin intake is associated with a reduced incidence of ovarian cancer and increased overall survival rate. We determined the effect of metformin on sphere formation, extracellular matrix invasion, and transcriptome profile of ovarian cancer cells (COVCAR) isolated from ascites of chickens that naturally developed ovarian cancer. We found that metformin treatment significantly decreased sphere formation and invasiveness of COVCAR cells. RNA-Seq data analysis revealed 0, 4, 365 differentially expressed genes in cells treated with 0.5, 1, 2 mM metformin, respectively compared to controls. Transcriptomic and ingenuity pathway analysis (IPA) revealed significant downregulation of MMP7, AICDA, GDPD2, APOC3, APOA1 and predicted inhibition of upstream regulators NFKB, STAT3, TP53 that are involved in epithelial-mesenchymal transition, DNA repair, and lipid metabolism. The analysis revealed significant upregulation of RASD2, IHH, CRABP-1 and predicted activation of upstream regulators VEGF and E2F1 that are associated with angiogenesis and cell cycle. Causal network analysis revealed novel pathways suggesting predicted inhibition of ovarian cancer through master regulator ASCL1 and dataset genes DCX, SEMA6B, HEY2, and KCNIP2. In summary, advanced pathway analysis in IPA revealed novel target genes, upstream regulators, and pathways affected by metformin treatment of COVCAR cells.


Subject(s)
Metformin/pharmacology , Ovarian Neoplasms/drug therapy , Transcriptome/drug effects , Animals , Ascites/drug therapy , Cell Line, Tumor , Cell Proliferation/drug effects , Chickens , Down-Regulation/drug effects , Epithelial-Mesenchymal Transition/drug effects , Female , Ovary/drug effects , Signal Transduction/drug effects , Up-Regulation/drug effects
17.
Microorganisms ; 10(1)2021 Dec 31.
Article in English | MEDLINE | ID: mdl-35056529

ABSTRACT

Strain MS-P2T was isolated from microbial mats associated with Mushroom Spring, an alkaline siliceous hot spring in Yellowstone National Park, WY, USA. The isolate grows chemoheterotrophically by oxygen-dependent respiration, and light stimulates photoheterotrophic growth under strictly oxic conditions. Strain MS-P2T synthesizes bacteriochlorophyll a and the carotenoid spirilloxanthin. However, photoautotrophic growth did not occur under oxic or anoxic conditions, suggesting that this strain should be classified as an aerobic anoxygenic phototrophic bacterium. Strain MS-P2T cells are motile, curved rods about 0.5 to 1.0 µm wide and 1.0 to 1.5 µm long. The optimum growth temperature is 45-50 °C, and the optimum pH for growth is circum-neutral (pH 7.0-7.5). Sequence analysis of the 16S rRNA gene revealed that strain MS-P2T is closely related to Elioraea species, members of the class Alphaproteobacteria, with a sequence identity of 96.58 to 98%. The genome of strain MS-P2T is a single circular DNA molecule of 3,367,643 bp with a mol% guanine-plus-cytosine content of 70.6%. Based on phylogenetic, physiological, biochemical, and genomic characteristics, we propose this bacteriochlorophyll a-containing isolate is a new species belonging to the genus Elioraea, with the suggested name Elioraeatepida. The type-strain is strain MS-P2T (= JCM33060T = ATCC TSD-174T).

18.
Int J Syst Evol Microbiol ; 70(11): 5701-5710, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32931408

ABSTRACT

A novel thermophilic phototrophic purple sulphur bacterium was isolated from microbial mats (56 °C) at Nakabusa hot springs, Nagano prefecture, Japan. Cells were motile, rod-shaped, stain Gram-negative and stored sulphur globules intracellularly. Bacteriochlorophyll a and carotenoids of the normal spirilloxanthin series were the major pigments. Dense liquid cultures were red in colour. Strain No.7T was able to grow photoautotrophically using sulfide, thiosulfate, sulfite and hydrogen (in the presence of sulfide) as electron donors and bicarbonate as the sole carbon source. Optimum growth occurred under anaerobic conditions in the light at 50 °C (range, 40-56 °C) and pH 7.2 (range, pH 7-8). Major fatty acids were C16 : 0 (46.8 %), C16 : 1 ω7c (19.9 %), C18 : 1 ω7c (21.1 %), C14 : 0 (4.6 %) and C18 : 0 (2.4 %). The polar lipid profile showed phosphatidylglycerol and unidentified aminophospholipids to be the major lipids. The only quinone detected was ubiquinone-8. 16S rRNA gene sequence comparisons indicated that the novel bacterium is only distantly related to Thermochromatium tepidum with a nucleotide identity of 90.4 %. The phylogenetic analysis supported the high novelty of strain No.7T with a long-branching phylogenetic position within the Chromatiaceae next to Thermochromatium tepidum. The genome comprised a circular chromosome of 2.99 Mbp (2 989 870 bp), included no plasmids and had a DNA G+C content of 61.2 mol%. Polyphasic taxonomic analyses of the isolate suggested strain No.7T is a novel genus within the Chromatiaceae. The proposed genus name of the second truly thermophilic purple sulphur bacterium is Caldichromatium gen. nov. with the type species Caldichromatium japonicum sp. nov. (DSM 110881=JCM 39101).


Subject(s)
Chromatiaceae/classification , Hot Springs/microbiology , Phylogeny , Bacterial Typing Techniques , Base Composition , Chromatiaceae/isolation & purification , DNA, Bacterial/genetics , Fatty Acids/chemistry , Japan , Phospholipids/chemistry , Pigmentation , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Sulfides , Sulfur , Thiosulfates , Ubiquinone/chemistry
19.
Front Microbiol ; 11: 1456, 2020.
Article in English | MEDLINE | ID: mdl-32733407

ABSTRACT

Wolbachia is an intracellular bacterium that blocks virus replication in insects and has been introduced into the mosquito, Aedes aegypti for the biocontrol of arboviruses including dengue, Zika, and chikungunya. Despite ongoing research, the mechanism of Wolbachia-mediated virus blocking remains unclear. We recently used experimental evolution to reveal that Wolbachia-mediated dengue blocking could be selected upon in the A. aegypti host and showed evidence that strong levels of blocking could be maintained by natural selection. In this study, we investigate the genetic variation associated with blocking and use these analyses to generate testable hypotheses surrounding the mechanism of Wolbachia-mediated dengue blocking. From our results, we hypothesize that Wolbachia may block virus replication by increasing the regeneration rate of mosquito cells via the Notch signaling pathway. We also propose that Wolbachia modulates the host's transcriptional pausing pathway either to prime the host's anti-viral response or to directly inhibit viral replication.

20.
BMC Bioinformatics ; 21(1): 292, 2020 Jul 08.
Article in English | MEDLINE | ID: mdl-32640986

ABSTRACT

BACKGROUND: Bioinformaticians collaborating with life scientists need software that allows them to involve their collaborators in the process of data analysis. RESULTS: We have developed a web application that allows researchers to publish and execute data analysis scripts. Within the platform bioinformaticians are able to deploy data analysis workflows (recipes) that their collaborators can execute via point and click interfaces. The results generated by the recipes are viewable via the web interface and consist of a snapshot of all the commands, printed messages and files that have been generated during the recipe run. A demonstration version of our software is available at https://www.bioinformatics.recipes/ . Detailed documentation for the software is available at: https://bioinformatics-recipes.readthedocs.io . The source code for the software is distributed through GitHub at https://github.com/ialbert/biostar-central . CONCLUSIONS: Our software platform supports collaborative interactions between bioinformaticians and life scientists. The software is presented via a web application that provides a high utility and user-friendly approach for conducting reproducible research. The recipes developed and shared through the web application are generic, with broad applicability and may be downloaded and executed on other computing platforms.


Subject(s)
Computational Biology/methods , Software , Data Analysis , Reproducibility of Results , User-Computer Interface , Workflow
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