Dynamic Organization of Chromatin Domains Revealed by Super-Resolution Live-Cell Imaging.

The eukaryotic genome is organized within cells as chromatin. For proper information output, higher-order chromatin structures can be regulated dynamically. How such structures form and behave in various cellular processes remains unclear. Here, by combining super-resolution imaging (photoactivated localization microscopy [PALM]) and single-nucleosome tracking, we developed a nuclear imaging system to visualize the higher-order structures along with their dynamics in live mammalian cells. We demonstrated that nucleosomes form compact domains with a peak diameter of ∼160 nm and move coherently in live cells. The heterochromatin-rich regions showed more domains and less movement. With cell differentiation, the domains became more apparent, with reduced dynamics. Furthermore, various perturbation experiments indicated that they are organized by a combination of factors, including cohesin and nucleosome-nucleosome interactions. Notably, we observed the domains during mitosis, suggesting that they act as building blocks of chromosomes and may serve as information units throughout the cell cycle.

Features of smaller ribosomes in candidate phyla radiation (CPR) bacteria revealed with a molecular evolutionary analysis.

The candidate phyla radiation (CPR) is a large bacterial group consisting mainly of uncultured lineages. They have small cells and small genomes, and they often lack ribosomal proteins uL1, bL9, and/or uL30, which are basically ubiquitous in non-CPR bacteria. Here, we comprehensively analyzed the genomic information on CPR bacteria and identified their unique properties. The distribution of protein lengths in CPR bacteria peaks at around 100-150 amino acids, whereas the position of the peak varies in the range of 100-300 amino acids in free-living non-CPR bacteria, and at around 100-200 amino acids in most symbiotic non-CPR bacteria. These results show that the proteins of CPR bacteria are smaller, on average, than those of free-living non-CPR bacteria, like those of symbiotic non-CPR bacteria. We found that ribosomal proteins bL28, uL29, bL32, and bL33 have been lost in CPR bacteria in a taxonomic lineage-specific manner. Moreover, the sequences of approximately half of all ribosomal proteins of CPR differ, in part, from those of non-CPR bacteria, with missing regions or specifically added regions. We also found that several regions in the 16S, 23S, and 5S rRNAs of CPR bacteria are lacking, which presumably caused the total predicted lengths of the three rRNAs of CPR bacteria to be smaller than those of non-CPR bacteria. The regions missing in the CPR ribosomal proteins and rRNAs are located near the surface of the ribosome, and some are close to one another. These observations suggest that ribosomes are smaller in CPR bacteria than those in free-living non-CPR bacteria, with simplified surface structures.

Study Profile of the Tsuruoka Metabolomics Cohort Study (TMCS).

The Tsuruoka Metabolomics Cohort Study (TMCS) is an ongoing population-based cohort study being conducted in the rural area of Yamagata Prefecture, Japan. This study aimed to enhance the precision prevention of multi-factorial, complex diseases, including non-communicable and aging-associated diseases, by improving risk stratification and prediction measures. At baseline, 11,002 participants aged 35-74 years were recruited in Tsuruoka City, Yamagata Prefecture, Japan, between 2012 and 2015, with an ongoing follow-up survey. Participants underwent various measurements, examinations, tests, and questionnaires on their health, lifestyle, and social factors. This study uses an integrative approach with deep molecular profiling to identify potential biomarkers linked to phenotypes that underpin disease pathophysiology and provide better mechanistic insights into social health determinants. The TMCS incorporates multi-omics data, including genetic and metabolomic analyses of 10,933 participants, and comprehensive data collection ranging from physical, psychological, behavioral, and social to biological data. The metabolome is used as a phenotypic probe because it is sensitive to changes in physiological and external conditions. The TMCS focuses on collecting outcomes for cardiovascular disease, cancer incidence and mortality, disability and functional decline due to aging and disease sequelae, and the variation in health status within the body represented by omics analysis that lies between exposure and disease. It contains several sub-studies on aging, heated tobacco products, and women's health. This study is notable for its robust design, high participation rate (89%), and long-term repeated surveys. Moreover, it contributes to precision prevention in Japan and East Asia as a well-established multi-omics platform.

Multicomponent nature underlies the extraordinary mechanical properties of spider dragline silk.

Dragline silk of golden orb-weaver spiders (Nephilinae) is noted for its unsurpassed toughness, combining extraordinary extensibility and tensile strength, suggesting industrial application as a sustainable biopolymer material. To pinpoint the molecular composition of dragline silk and the roles of its constituents in achieving its mechanical properties, we report a multiomics approach, combining high-quality genome sequencing and assembly, silk gland transcriptomics, and dragline silk proteomics of four Nephilinae spiders. We observed the consistent presence of the MaSp3B spidroin unique to this subfamily as well as several nonspidroin SpiCE proteins. Artificial synthesis and the combination of these components in vitro showed that the multicomponent nature of dragline silk, including MaSp3B and SpiCE, along with MaSp1 and MaSp2, is essential to realize the mechanical properties of spider dragline silk.

A population-based urinary and plasma metabolomics study of environmental exposure to cadmium.

BACKGROUND: The application of metabolomics-based profiles in environmental epidemiological studies is a promising approach to refine the process of health risk assessment. We aimed to identify potential metabolomics-based profiles in urine and plasma for the detection of relatively low-level cadmium (Cd) exposure in large population-based studies. METHOD: We analyzed 123 urinary metabolites and 94 plasma metabolites detected in fasting urine and plasma samples collected from 1,412 men and 2,022 women involved in the Tsuruoka Metabolomics Cohort Study. Regression analysis was performed for urinary N-acetyl-beta-D-glucosaminidase (NAG), plasma, and urinary metabolites as dependent variables, and urinary Cd (U-Cd, quartile) as an independent variable. The multivariable regression model included age, gender, systolic blood pressure, smoking, rice intake, BMI, glycated hemoglobin, low-density lipoprotein cholesterol, alcohol consumption, physical activity, educational history, dietary energy intake, urinary Na/K ratio, and uric acid. Pathway-network analysis was carried out to visualize the metabolite networks linked to Cd exposure. RESULT: Urinary NAG was positively associated with U-Cd, but not at lower concentrations (Q2). Among urinary metabolites in the total population, 45 metabolites showed associations with U-Cd in the unadjusted and adjusted models after adjusting for the multiplicity of comparison with FDR. There were 12 urinary metabolites which showed consistent associations between Cd exposure from Q2 to Q4. Among plasma metabolites, six cations and one anion were positively associated with U-Cd, whereas alanine, creatinine, and isoleucine were negatively associated with U-Cd. Our results were robust by statistical adjustment of various confounders. Pathway-network analysis revealed metabolites and upstream regulator changes associated with mitochondria (ACACB, UCP2, and metabolites related to the TCA cycle). CONCLUSION: These results suggested that U-Cd was associated with metabolites related to upstream mitochondrial dysfunction in a dose-dependent manner. Our data will help develop environmental Cd exposure profiles for human populations.

Systematic Analysis of Diverse Polynucleotide Kinase Clp1 Family Proteins in Eukaryotes: Three Unique Clp1 Proteins of Trypanosoma brucei.

The Clp1 family proteins, consisting of the Clp1 and Nol9/Grc3 groups, have polynucleotide kinase (PNK) activity at the 5' end of RNA strands and are important enzymes in the processing of some precursor RNAs. However, it remains unclear how this enzyme family diversified in the eukaryotes. We performed a large-scale molecular evolutionary analysis of the full-length genomes of 358 eukaryotic species to classify the diverse Clp1 family proteins. The average number of Clp1 family proteins in eukaryotes was 2.3 ± 1.0, and most representative species had both Clp1 and Nol9/Grc3 proteins, suggesting that the Clp1 and Nol9/Grc3 groups were already formed in the eukaryotic ancestor by gene duplication. We also detected an average of 4.1 ± 0.4 Clp1 family proteins in members of the protist phylum Euglenozoa. For example, in Trypanosoma brucei, there are three genes of the Clp1 group and one gene of the Nol9/Grc3 group. In the Clp1 group proteins encoded by these three genes, the C-terminal domains have been replaced by unique characteristics domains, so we designated these proteins Tb-Clp1-t1, Tb-Clp1-t2, and Tb-Clp1-t3. Experimental validation showed that only Tb-Clp1-t2 has PNK activity against RNA strands. As in this example, N-terminal and C-terminal domain replacement also contributed to the diversification of the Clp1 family proteins in other eukaryotic species. Our analysis also revealed that the Clp1 family proteins in humans and plants diversified through isoforms created by alternative splicing.

Metabolomics profiles alterations in cigarette smokers and heated tobacco product users.

BACKGROUND: Heated tobacco products (HTPs) have gained global popularity, but their health risks remain unclear. Therefore, the current study aimed to identify plasma metabolites associated with smoking and HTP use in a large Japanese population to improve health risk assessment. METHODS: Metabolomics data from 9,922 baseline participants of the Tsuruoka Metabolomics Cohort Study (TMCS) were analyzed to determine the association between smoking habits and plasma metabolites. Moreover, alterations in smoking-related metabolites among HTP users were examined based on data obtained from 3,334 participants involved from April 2018 to June 2019 in a follow-up survey. RESULTS: Our study revealed that cigarette smokers had metabolomics profiles distinct from never smokers, with 22 polar metabolites identified as candidate biomarkers for smoking. These biomarker profiles of HTP users were closer to those of cigarette smokers than those of never smokers. The concentration of glutamate was higher in cigarette smokers, and biomarkers involved in glutamate metabolism were also associated with cigarette smoking and HTP use. Network pathway analysis showed that smoking was associated with the glutamate pathway, which could lead to endothelial dysfunction and atherosclerosis of the vessels. CONCLUSIONS: Our study showed that the glutamate pathway is affected by habitual smoking. These changes in the glutamate pathway may partly explain the mechanism by which cigarette smoking causes cardiovascular disease. HTP use was also associated with glutamate metabolism, indicating that HTP use may contribute to the development of cardiovascular disease through mechanisms similar to those in cigarette use.

iDMET: network-based approach for integrating differential analysis of cancer metabolomics.

BACKGROUND: Comprehensive metabolomic analyses have been conducted in various institutes and a large amount of metabolomic data are now publicly available. To help fully exploit such data and facilitate their interpretation, metabolomic data obtained from different facilities and different samples should be integrated and compared. However, large-scale integration of such data for biological discovery is challenging given that they are obtained from various types of sample at different facilities and by different measurement techniques, and the target metabolites and sensitivities to detect them also differ from study to study. RESULTS: We developed iDMET, a network-based approach to integrate metabolomic data from different studies based on the differential metabolomic profiles between two groups, instead of the metabolite profiles themselves. As an application, we collected cancer metabolomic data from 27 previously published studies and integrated them using iDMET. A pair of metabolomic changes observed in the same disease from two studies were successfully connected in the network, and a new association between two drugs that may have similar effects on the metabolic reactions was discovered. CONCLUSIONS: We believe that iDMET is an efficient tool for integrating heterogeneous metabolomic data and discovering novel relationships between biological phenomena.

Time-series transcriptomic screening of factors contributing to the cross-tolerance to UV radiation and anhydrobiosis in tardigrades.

BACKGROUND: Tardigrades are microscopic animals that are capable of tolerating extreme environments by entering a desiccated state of suspended animation known as anhydrobiosis. While antioxidative stress proteins, antiapoptotic pathways and tardigrade-specific intrinsically disordered proteins have been implicated in the anhydrobiotic machinery, conservation of these mechanisms is not universal within the phylum Tardigrada, suggesting the existence of overlooked components. RESULTS: Here, we show that a novel Mn-dependent peroxidase is an important factor in tardigrade anhydrobiosis. Through time-series transcriptome analysis of Ramazzottius varieornatus specimens exposed to ultraviolet light and comparison with anhydrobiosis entry, we first identified several novel gene families without similarity to existing sequences that are induced rapidly after stress exposure. Among these, a single gene family with multiple orthologs that is highly conserved within the phylum Tardigrada and enhances oxidative stress tolerance when expressed in human cells was identified. Crystallographic study of this protein suggested Zn or Mn binding at the active site, and we further confirmed that this protein has Mn-dependent peroxidase activity in vitro. CONCLUSIONS: Our results demonstrated novel mechanisms for coping with oxidative stress that may be a fundamental mechanism of anhydrobiosis in tardigrades. Furthermore, localization of these sets of proteins mainly in the Golgi apparatus suggests an indispensable role of the Golgi stress response in desiccation tolerance.

Salivary metabolomics with machine learning for colorectal cancer detection.

As the worldwide prevalence of colorectal cancer (CRC) increases, it is vital to reduce its morbidity and mortality through early detection. Saliva-based tests are an ideal noninvasive tool for CRC detection. Here, we explored and validated salivary biomarkers to distinguish patients with CRC from those with adenoma (AD) and healthy controls (HC). Saliva samples were collected from patients with CRC, AD, and HC. Untargeted salivary hydrophilic metabolite profiling was conducted using capillary electrophoresis-mass spectrometry and liquid chromatography-mass spectrometry. An alternative decision tree (ADTree)-based machine learning (ML) method was used to assess the discrimination abilities of the quantified metabolites. A total of 2602 unstimulated saliva samples were collected from subjects with CRC (n = 235), AD (n = 50), and HC (n = 2317). Data were randomly divided into training (n = 1301) and validation datasets (n = 1301). The clustering analysis showed a clear consistency of aberrant metabolites between the two groups. The ADTree model was optimized through cross-validation (CV) using the training dataset, and the developed model was validated using the validation dataset. The model discriminating CRC + AD from HC showed area under the receiver-operating characteristic curves (AUC) of 0.860 (95% confidence interval [CI]: 0.828-0.891) for CV and 0.870 (95% CI: 0.837-0.903) for the validation dataset. The other model discriminating CRC from AD + HC showed an AUC of 0.879 (95% CI: 0.851-0.907) and 0.870 (95% CI: 0.838-0.902), respectively. Salivary metabolomics combined with ML demonstrated high accuracy and versatility in detecting CRC.

Impact of Selected Initial Titration Schedules on Safety and Long-Term Effectiveness of Lamotrigine for the Treatment of Mood Disorders.

PURPOSE: Lamotrigine (LTG) is used for treatment of mood disorders, but it is associated with the risk of rash occurrence in the initial administration phase. Although slow titration reduces this risk, its effectiveness in the treatment of mood disorders has not been verified. The effects of titration method on the safety and effectiveness of LTG for the treatment of mood disorders were examined in this study. METHODS: This retrospective cohort study included 312 patients with mood disorders who underwent initiation of LTG therapy. Data regarding baseline demographics, titration schedules, concomitant medications, and time to and cause of discontinuation of LTG were collected. A multivariate analysis was used to evaluate the effects of the titration schedules. The 12-month effectiveness was also evaluated. RESULTS: The 12-month discontinuation rate of LTG was 16.7%. The most frequent cause of discontinuation was development of a rash (47.7%, n = 312). Fast titration (adjusted odds ratio, 8.15) significantly increased the risk of rash development, and slow titration (adjusted odds ratio, 0.29) significantly decreased this risk. The time to all-cause discontinuation was not significantly different between the slow and standard titration groups (n = 303). After 12 months of treatment, the condition of 46.7% patients were rated much or very much improved using CGI-C. CONCLUSIONS: Although slow titration of LTG reduces the occurrence of a rash, it is not more effective than standard titration in the long term. Optimizing the initial LTG titration schedule for patients with mood disorders is challenging.

Multiomics study of a heterotardigrade, Echinisicus testudo, suggests the possibility of convergent evolution of abundant heat-soluble proteins in Tardigrada.

BACKGROUND: Many limno-terrestrial tardigrades can enter an ametabolic state, known as anhydrobiosis, upon desiccation, in which the animals can withstand extreme environments. Through genomics studies, molecular components of anhydrobiosis are beginning to be elucidated, such as the expansion of oxidative stress response genes, loss of stress signaling pathways, and gain of tardigrade-specific heat-soluble protein families designated CAHS and SAHS. However, to date, studies have predominantly investigated the class Eutardigrada, and molecular mechanisms in the remaining class, Heterotardigrada, still remains elusive. To address this gap in the research, we report a multiomics study of the heterotardigrade Echiniscus testudo, one of the most desiccation-tolerant species which is not yet culturable in laboratory conditions. RESULTS: In order to elucidate the molecular basis of anhydrobiosis in E. testudo, we employed a multi-omics strategy encompassing genome sequencing, differential transcriptomics, and proteomics. Using ultra-low input library sequencing protocol from a single specimen, we sequenced and assembled the 153.7 Mbp genome annotated using RNA-Seq data. None of the previously identified tardigrade-specific abundant heat-soluble genes was conserved, while the loss and expansion of existing pathways were partly shared. Furthermore, we identified two families novel abundant heat-soluble proteins, which we named E. testudo Abundant Heat Soluble (EtAHS), that are predicted to contain large stretches of disordered regions. Likewise the AHS families in eutardigrada, EtAHS shows structural changes from random coil to alphahelix as the water content was decreased in vitro. These characteristics of EtAHS proteins are analogous to those of CAHS in eutardigrades, while there is no conservation at the sequence level. CONCLUSIONS: Our results suggest that Heterotardigrada have partly shared but distinct anhydrobiosis machinery compared with Eutardigrada, possibly due to convergent evolution within Tardigrada. (276/350).

Reprogramming of glutamine metabolism via glutamine synthetase silencing induces cisplatin resistance in A2780 ovarian cancer cells.

BACKGROUND: Cisplatin (CDDP) significantly prolongs survival in various cancers, but many patients also develop resistance that results in treatment failure. Thus, this study aimed to elucidate the underlying mechanisms by which ovarian cancer cells acquire CDDP resistance. METHODS: We evaluated the metabolic profiles in CDDP-sensitive ovarian cancer A2780 cells and CDDP-resistant A2780cis cells using capillary electrophoresis-time-of-flight mass spectrometry (CE-TOFMS). We further examined the expression of glutamine metabolism enzymes using real-time PCR and Western blot analyses. Cell viability was accessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: The results showed that levels of glutamine, glutamate, and glutathione (GSH), a key drug resistance mediator synthesized from glutamate, were significantly elevated in A2780cis cells than those in A2780 cells. Furthermore, glutamine starvation decreased the GSH levels and CDDP resistance in A2780cis cells. Interestingly, the expression of glutamine synthetase (GS/GLUL), which synthesizes glutamine from glutamate and thereby negatively regulates GSH production, was almost completely suppressed in resistant A2780cis cells. In addition, treatment of A2780cis cells with 5-aza-2'-deoxycytidine, a DNA-demethylating agent, restored GS expression and reduced CDDP resistance. In contrast, GS knockdown in CDDP-sensitive A2780 cells induced CDDP resistance. CONCLUSIONS: The results indicate that upregulation of GSH synthesis from glutamine via DNA methylation-mediated silencing of GS causes CDDP resistance in A2780cis cells. Therefore, glutamine metabolism could be a novel therapeutic target against CDDP resistance.

Fast and global detection of periodic sequence repeats in large genomic resources.

Periodically repeating DNA and protein elements are involved in various important biological events including genomic evolution, gene regulation, protein complex formation, and immunity. Notably, the currently used genome editing tools such as ZFNs, TALENs, and CRISPRs are also all associated with periodically repeating biomolecules of natural organisms. Despite the biological importance of periodically repeating sequences and the expectation that new genome editing modules could be discovered from such periodical repeats, no software that globally detects such structured elements in large genomic resources in a high-throughput and unsupervised manner has been developed. We developed new software, SPADE (Search for Patterned DNA Elements), that exhaustively explores periodic DNA and protein repeats from large-scale genomic datasets based on k-mer periodicity evaluation. With a simple constraint, sequence periodicity, SPADE captured reported genome-editing-associated sequences and other protein families involving repeating domains such as tetratricopeptide, ankyrin and WD40 repeats with better performance than the other software designed for limited sets of repetitive biomolecular sequences, suggesting the high potential of this software to contribute to the discovery of new biological events and new genome editing modules.

Mass Spectrometry-Compatible Subcellular Fractionation for Proteomics.

We found that nuclear envelopes stabilize against surfactants in the presence of ethylene glycol (EG). We, therefore, developed a novel subcellular fractionation approach for proteomics using RIPA buffer containing EG and phase transfer surfactants. This method involves separating the cells into the cytoplasm, organelles, and nucleus, including intermediate filaments without ultracentrifugation. These fractions are directly applicable to sample preparation for shotgun proteomics as they have no mass spectrometry (MS)-incompatible chemicals, whereas those separated by traditional fractionation protocols require desalting. This protocol is successfully applied to subcellular fractionation with only 3.5 × 105 cells. Here, it was combined with phosphoproteomics and proteomics to identify phosphorylation sites regulating protein subcellular localization. In total, 59 phosphorylation sites on 42 phosphopeptides and 32 proteins showing different enrichment patterns between phosphoproteomics and the corresponding proteomics were identified, which are potential candidate sites to regulate the protein subcellular localization, including serine 706 on CD44 and serine 22 on lamin A/C.

Comprehensive Dipeptide Profiling and Quantitation by Capillary Electrophoresis and Liquid Chromatography Coupled with Tandem Mass Spectrometry.

Dipeptides have attracted much attention as post-amino acids with physical properties and functions different from those of amino acids. However, a given dipeptide cannot be distinguished by mass spectrometry from its structural isomer with an opposite amino acid binding order unless these isomers are separated before introduction, which complicates the comprehensive analysis of dipeptides. Herein, a novel analytical platform for dipeptide analysis by capillary electrophoresis tandem mass spectrometry and liquid chromatography tandem mass spectrometry is developed. This method is used to quantitate 335 dipeptides and achieves excellent separation of structural isomers with opposite binding orders, high correlation coefficients, and low instrumental detection limits (0.088-83.1 nM). Moreover, acceptable recoveries (70-135%) are observed for most tested dipeptides in chicken liver samples spiked both before and after preparation. The developed method is also applied to the quantitation of dipeptides in the livers of mice fed different diets to detect 236 dipeptides, and the shift from a normal diet to a high-fat diet is shown to increase/decrease (p < 0.05, fold-change < 0.5) the contents of 0/29 dipeptides, respectively. The developed method is expected to facilitate the search for new dipeptide applications such as novel functional components of foods and biomarkers of diseases.

AMPK activity is required for the induction of anhydrobiosis in a tardigrade Hypsibius exemplaris, and its potential up-regulator is PP2A.

The anhydrobiotic tardigrade, Hypsibius exemplaris, was previously considered to require de novo gene expression and protein phosphatase 1 (PP1) and protein phosphatase 2A (PP2A) activity for successful anhydrobiosis. These indicate that H. exemplaris has signal transduction systems responding to desiccation stress, with the involvement of phosphorylation events. To this end, we carried out time-series phosphoproteomics of H. exemplaris exposed to mild desiccation stress and detected 48 phosphoproteins with significant differential regulations. Among them, immediate and successive reduction of phosphorylation levels of AMP-activated protein kinase (AMPK) was observed. The subsequent chemical genetic approach showed that AMPK was activated during the preconditioning stage for anhydrobiosis, and inhibition of its activity impaired successful anhydrobiosis. As PP2A is known to dephosphorylate AMPK in other organisms, we suggested that decreased phosphorylation levels of AMPK upon mild desiccation stress were caused by dephosphorylation by PP2A. Accordingly, phosphoproteomics of animals pre-treated with the PP1/PP2A inhibitor cantharidic acid (CA) lacked the decrease in phosphorylation levels of AMPK. These observations suggest that AMPK activity is required for successful anhydrobiosis in H. exemplaris, and its phosphorylation state is possibly regulated by PP2A.

Comparative genomics of the tardigrades Hypsibius dujardini and Ramazzottius varieornatus.

Tardigrada, a phylum of meiofaunal organisms, have been at the center of discussions of the evolution of Metazoa, the biology of survival in extreme environments, and the role of horizontal gene transfer in animal evolution. Tardigrada are placed as sisters to Arthropoda and Onychophora (velvet worms) in the superphylum Panarthropoda by morphological analyses, but many molecular phylogenies fail to recover this relationship. This tension between molecular and morphological understanding may be very revealing of the mode and patterns of evolution of major groups. Limnoterrestrial tardigrades display extreme cryptobiotic abilities, including anhydrobiosis and cryobiosis, as do bdelloid rotifers, nematodes, and other animals of the water film. These extremophile behaviors challenge understanding of normal, aqueous physiology: how does a multicellular organism avoid lethal cellular collapse in the absence of liquid water? Meiofaunal species have been reported to have elevated levels of horizontal gene transfer (HGT) events, but how important this is in evolution, and particularly in the evolution of extremophile physiology, is unclear. To address these questions, we resequenced and reassembled the genome of H. dujardini, a limnoterrestrial tardigrade that can undergo anhydrobiosis only after extensive pre-exposure to drying conditions, and compared it to the genome of R. varieornatus, a related species with tolerance to rapid desiccation. The 2 species had contrasting gene expression responses to anhydrobiosis, with major transcriptional change in H. dujardini but limited regulation in R. varieornatus. We identified few horizontally transferred genes, but some of these were shown to be involved in entry into anhydrobiosis. Whole-genome molecular phylogenies supported a Tardigrada+Nematoda relationship over Tardigrada+Arthropoda, but rare genomic changes tended to support Tardigrada+Arthropoda.

Global metabolic reprogramming of colorectal cancer occurs at adenoma stage and is induced by MYC.

Cancer cells alter their metabolism for the production of precursors of macromolecules. However, the control mechanisms underlying this reprogramming are poorly understood. Here we show that metabolic reprogramming of colorectal cancer is caused chiefly by aberrant MYC expression. Multiomics-based analyses of paired normal and tumor tissues from 275 patients with colorectal cancer revealed that metabolic alterations occur at the adenoma stage of carcinogenesis, in a manner not associated with specific gene mutations involved in colorectal carcinogenesis. MYC expression induced at least 215 metabolic reactions by changing the expression levels of 121 metabolic genes and 39 transporter genes. Further, MYC negatively regulated the expression of genes involved in mitochondrial biogenesis and maintenance but positively regulated genes involved in DNA and histone methylation. Knockdown of MYC in colorectal cancer cells reset the altered metabolism and suppressed cell growth. Moreover, inhibition of MYC target pyrimidine synthesis genes such as CAD, UMPS, and CTPS blocked cell growth, and thus are potential targets for colorectal cancer therapy.

Comparison of the transcriptomes of two tardigrades with different hatching coordination.

BACKGROUND: Tardigrades are microscopic organisms, famous for their tolerance against extreme environments. The establishment of rearing systems of multiple species has allowed for comparison of tardigrade physiology, in particular in embryogenesis. Interestingly, in-lab cultures of limnic species showed smaller variation in hatching timing than terrestrial species, suggesting a hatching regulation mechanism acquired by adaptation to their habitat. RESULTS: To this end, we screened for coordinated gene expression during the development of two species of tardigrades, Hypsibius exemplaris and Ramazzottius varieornatus, and observed induction of the arthropod molting pathway. Exposure of ecdysteroids and juvenile hormone analog affected egg hatching but not embryonic development in only the limnic H. exemplaris. CONCLUSION: These observations suggest a hatching regulation mechanism by the molting pathway in H. exemplaris.