Canonical Features Research Articles

The massed-spaced learning effect in non-neural human cells

The massed-spaced effect is a hallmark feature of memory formation. We now demonstrate this effect in two separate non-neural, immortalized cell lines stably expressing a short-lived luciferase reporter controlled by a CREB-dependent promoter. We emulate training using repeated pulses of forskolin and/or phorbol ester, and, as a proxy for memory, measure luciferase expression at various points after training. Four spaced pulses of either agonist elicit stronger and more sustained luciferase expression than a single “massed” pulse. Spaced pulses also result in stronger and more sustained activation of molecular factors critical for memory formation, ERK and CREB, and inhibition of ERK or CREB blocks the massed-spaced effect. Our findings show that canonical features of memory do not necessarily depend on neural circuitry, but can be embedded in the dynamics of signaling cascades conserved across different cell types.

Enhancing Oral Squamous Cell Carcinoma Detection Using Histopathological Images: A Deep Feature Fusion and Improved Haris Hawks Optimization-Based Framework.

Oral cancer, also known as oral squamous cell carcinoma (OSCC), is one of the most prevalent types of cancer and caused 177,757 deaths worldwide in 2020, as reported by the World Health Organization. Early detection and identification of OSCC are highly correlated with survival rates. Therefore, this study presents an automatic image-processing-based machine learning approach for OSCC detection. Histopathological images were used to compute deep features using various pretrained models. Based on the classification performance, the best features (ResNet-101 and EfficientNet-b0) were merged using the canonical correlation feature fusion approach, resulting in an enhanced classification performance. Additionally, the binary-improved Haris Hawks optimization (b-IHHO) algorithm was used to eliminate redundant features and further enhance the classification performance, leading to a high classification rate of 97.78% for OSCC. The b-IHHO trained the k-nearest neighbors model with an average feature vector size of only 899. A comparison with other wrapper-based feature selection approaches showed that the b-IHHO results were statistically more stable, reliable, and significant (p < 0.01). Moreover, comparisons with those other state-of-the-art (SOTA) approaches indicated that the b-IHHO model offered better results, suggesting that the proposed framework may be applicable in clinical settings to aid doctors in OSCC detection.

Momordica charantia L.-derived exosome-like nanovesicles stabilize p62 expression to ameliorate doxorubicin cardiotoxicity

BackgroundDoxorubicin (DOX) is a first-line chemotherapeutic drug for various malignancies that causes cardiotoxicity. Plant-derived exosome-like nanovesicles (P-ELNs) are growing as novel therapeutic agents. Here, we investigated the protective effects in DOX cardiotoxicity of ELNs from Momordica charantia L. (MC-ELNs), a medicinal plant with antioxidant activity.ResultsWe isolated MC-ELNs using ultracentrifugation and characterized them with canonical mammalian extracellular vesicles features. In vivo studies proved that MC-ELNs ameliorated DOX cardiotoxicity with enhanced cardiac function and myocardial structure. In vitro assays revealed that MC-ELNs promoted cell survival, diminished reactive oxygen species, and protected mitochondrial integrity in DOX-treated H9c2 cells. We found that DOX treatment decreased the protein level of p62 through ubiquitin-dependent degradation pathway in H9c2 and NRVM cells. However, MC-ELNs suppressed DOX-induced p62 ubiquitination degradation, and the recovered p62 bound with Keap1 promoting Nrf2 nuclear translocation and the expressions of downstream gene HO-1. Furthermore, both the knockdown of Nrf2 and the inhibition of p62-Keap1 interaction abrogated the cardioprotective effect of MC-ELNs.ConclusionsOur findings demonstrated the therapeutic beneficials of MC-ELNs via increasing p62 protein stability, shedding light on preventive approaches for DOX cardiotoxicity.

Distinct propagating and standing modes of tropical intraseasonal variability as represented by the two principal oscillation patterns

Although the tropical intraseaonal variability (TISV), as the most important predictability sources for subseasonal-to-seasonal (S2S) prediction, is dominated by Madden-Julian oscillation (MJO), its significant fraction does not always share the canonical MJO features, especially when the convective activity arrives at Maritime Continent. In this study, using principal oscillation pattern (POP) analysis on the combined fields of daily equatorial convection and zonal wind, two distinct leading TISV modes with relatively slower e-folding decay rates are identified. One is an oscillatory mode with the period of 51 days and e-folding time of 19 days, capturing the eastward propagating (EP) feature of the canonical MJO. The other is a non-oscillatory damping mode with e-folding time of 13.6 days, capturing a standing dipole (SD) with convection anomalies centered over the Maritime Continent and tropical central Pacific, respectively. Compared to the EP mode, the leading moisture anomalies at low level to the east of convection center are diminish for the SD mode, and instead, the strong negative anomalies of moisture and subsidence motion emerge in the tropical central Pacific area, which may be responsible for the distinct propagation features. Without filtering methods used, timeseries of the two POPs could be applied to the real-time monitoring of EP and SD events in the phase-space diagram. The two modes can serve as the simple and objective approach for a better characterization for diverse natures of TISV beyond the canonical MJO description, which may further shed light on dynamics of the TISV and its predictability.

Interpretable video-based tracking and quantification of parkinsonism clinical motor states

Quantification of motor symptom progression in Parkinson’s disease (PD) patients is crucial for assessing disease progression and for optimizing therapeutic interventions, such as dopaminergic medications and deep brain stimulation. Cumulative and heuristic clinical experience has identified various clinical signs associated with PD severity, but these are neither objectively quantifiable nor robustly validated. Video-based objective symptom quantification enabled by machine learning (ML) introduces a potential solution. However, video-based diagnostic tools often have implementation challenges due to expensive and inaccessible technology, and typical “black-box” ML implementations are not tailored to be clinically interpretable. Here, we address these needs by releasing a comprehensive kinematic dataset and developing an interpretable video-based framework that predicts high versus low PD motor symptom severity according to MDS-UPDRS Part III metrics. This data driven approach validated and robustly quantified canonical movement features and identified new clinical insights, not previously appreciated as related to clinical severity, including pinkie finger movements and lower limb and axial features of gait. Our framework is enabled by retrospective, single-view, seconds-long videos recorded on consumer-grade devices such as smartphones, tablets, and digital cameras, thereby eliminating the requirement for specialized equipment. Following interpretable ML principles, our framework enforces robustness and interpretability by integrating (1) automatic, data-driven kinematic metric evaluation guided by pre-defined digital features of movement, (2) combination of bi-domain (body and hand) kinematic features, and (3) sparsity-inducing and stability-driven ML analysis with simple-to-interpret models. These elements ensure that the proposed framework quantifies clinically meaningful motor features useful for both ML predictions and clinical analysis.

Post-compulsory schooling of youth in Turkey: a case of pro-cyclical enrollment

PurposeThis study investigates the effect of business cycles on school enrollment in Turkey. During recessions, school enrollment might increase as opportunity cost of schooling declines, yet it might also decrease because of reduced income households have for education. Which effect dominates depends on the context. We empirically explore this in a context displaying canonical features of developing countries.Design/methodology/approachUsing the Turkish Household Labor Force Survey data for a period covering the Great Recession, we estimate the effect of unemployment rate separately for enrollments in general and vocational high schools and in undergraduate programs. To understand the cyclicality, we use a probit model with the regional and time variations in unemployment rates. We also build a simple theoretical model of work-schooling choice to interpret the findings.FindingsWe find that the likelihood of enrolling in general high schools and undergraduate programs declines with higher adult unemployment rates, but the likelihood of enrollment in vocational high schools increases. Confronting these empirical findings with the theoretical model suggests that the major factor in enrollment cyclicality in Turkey is how parental resources allocated to education change during recessions by schooling type.Originality/valueOur finding of pro-cyclical enrollment in academically oriented programs is in contrast with counter-cyclicality documented for similar programs in developed countries, which highlights the importance of income related factors in developing-country contexts. Our heterogeneous findings for general and vocational high schools are also novel.

Abstract 1044: Single Cell RNA-sequencing Of Endothelial Cells In Atherosclerosis Reveals A Single Phenotypic Transition To A Mesenchymal Cell State

Introduction: Coronary artery disease (CAD) is the leading cause of mortality in the United States. Multiple cell types contribute to the atherosclerotic plaques causing CAD, influencing disease burden. Endothelial-to-mesenchymal transition (EndMT), the process by which endothelial cells (ECs) acquire characteristics of mesenchymal cells and loose canonical endothelial features, is correlated with an unstable plaque phenotype, although this transition remains poorly characterized. Hypothesis: A specific population of ECs may undergo EndMT, potentially contributing to the progression of atherosclerosis. Methods: Endothelial-specific lineage-tracing was induced in Tg Cdh5-CreERT2 , ApoE -/- mice, followed by 16 weeks of high-fat diet (HFD) to produce atherosclerosis. Aortic roots were collected from male and female disease-condition animals (n=13) and a baseline cohort that was not fed HFD (n=6). Single cell RNA sequencing was performed using 10X Genomics and analyzed with the Seurat package. RNAscope staining of sections (n=10 per genotype) was performed to characterize the lesion. Results: Multiple endothelial subtypes in the aortic root were identified. One population of arterial ECs, characterized by Klk10 expression, appears to give rise to a disease-specific population of ECs expressing Edn1 . These ECs appear to acquire a mesenchymal phenotype, consistent with the occurrence of EndMT. RNAscope staining revealed Edn1 + cells at the luminal surface and deep within the plaque. Upstream regulator analysis comparing Edn1+ and Klk10+ populations predict EndMT-associated transcription regulators including SNAI2, TWIST2, STAT3, SNAI1 and YAP1 as drivers of this transition. This analysis predicts upregulation of both fibrotic and cytokine signaling. In contrast to a previous study of carotid ECs under disturbed flow that identified multiple disparate EC phenotypes, we observed a single disease-associated EC transition. Conclusion: We identified ECs undergoing EndMT in a HFD-induced mouse model of atherosclerosis and determined that this transition is the primary EC cell state transition during disease. Thus, the process of EndMT may account for both mesenchymal and inflammatory changes observed in ECs during atherosclerosis.

Efficiency and Incidence of Taxation with Free Entry and Love-of-Variety Preferences

We develop a theory of commodity taxation featuring imperfect competition along with love-of-variety preferences and endogenous firm entry and exit. We derive new formulas for the efficiency and pass-through of specific and ad valorem taxes. These formulas unify existing canonical ones and feature a new term capturing the effect of variety on consumer surplus. As a proof of concept, we use theoretical formulas to identify love-of-variety preferences in an empirical application. Our welfare analysis shows that the marginal excess burden is sensitive to the estimated love of variety, which overturns classical results on the desirability of ad valorem versus specific taxation. (JEL D11, D21, D91, H25)

The p21+ perinecrotic hepatocytes produce the chemokine CXCL14 after a severe acetaminophen overdose promoting hepatocyte injury and delaying regeneration

Fifty percent of all acute liver failure (ALF) cases in the United States are due to acetaminophen (APAP) overdose. Assessment of canonical features of liver injury, such as plasma alanine aminotransferase activities are poor predictors of acute liver failure (ALF), suggesting the involvement of additional mechanisms independent of hepatocyte death. Previous work demonstrated a severe overdose of APAP results in impaired regeneration, the induction of senescence by p21, and increased mortality. We hypothesized that a discrete population of p21+ hepatocytes acquired a secretory phenotype that directly impedes liver recovery after a severe APAP overdose. Leveraging in-house human APAP explant liver and publicly available single-nuclei RNAseq data, we identified a subpopulation of p21+ hepatocytes enriched in a unique secretome of factors, such as CXCL14. Spatial transcriptomics in the mouse model of APAP overdose confirmed the presence of a p21+ hepatocyte population that directly surrounded the necrotic areas. In both male and female mice, we found a dose-dependent induction of p21 and persistent circulating levels of the p21-specific constituent, CXCL14, in the plasma after a severe APAP overdose. In parallel experiments, we targeted either the putative senescent hepatocytes with the senolytic drugs, dasatinib and quercetin, or CXCL14 with a neutralizing antibody. We found that targeting CXCL14 greatly enhanced liver recovery after APAP-induced liver injury, while targeting senescent hepatocytes had no effect. These data support the conclusion that the sustained induction of p21 in hepatocytes with persistent CXCL14 secretion are critical mechanistic events leading to ALF in mice and human patients.

Structure, dynamics, and redox reactivity of an all-purpose flavodoxin

The flavodoxin of Rhodopseudomonas palustris CGA009 (Rp9Fld) supplies highly reducing equivalents to crucial enzymes such as hydrogenase, especially when the organism is iron-restricted. By acquiring those electrons from photodriven electron flow via the bifurcating electron transfer flavoprotein (ETF), Rp9Fld provides solar power to vital metabolic processes. To understand Rp9Fld's ability to work with diverse partners, we solved its crystal structure. We observe the canonical flavodoxin (Fld) fold and features common to other long-chain Flds, but not all the surface loops thought to recognize partner proteins. Moreover some of the loops display alternative structures and dynamics. To advance studies of protein-protein associations and conformational consequences, we assigned the 19F NMR signals of all 5 tyrosines (Tyrs). Our electrochemical measurements show that incorporation of 3-19F-Tyr in place of Tyr has only a modest effect on Rp9Fld's redox properties even though Tyrs flank the flavin on both sides. Meanwhile, the 19F probes demonstrate the expected paramagnetic effect, with signals from nearby Tyrs becoming broadened beyond detection when the flavin semiquinone is formed. However the temperature dependencies of chemical shifts and linewidths reveal dynamics affecting loops close to the flavin, and regions that bind to partners in a variety of systems. These coincide with patterns of amino acid type conservation but not retention of specific residues, arguing against detailed specificity with respect to partners. We propose that the loops surrounding the flavin adopt altered conformations upon binding to partners and may even participate actively in electron transfer.

Bacterial Lactonases ZenA with Noncanonical Structural Features Hydrolyze the Mycotoxin Zearalenone.

Zearalenone (ZEN) is a mycoestrogenic polyketide produced by Fusarium graminearum and other phytopathogenic members of the genus Fusarium. Contamination of cereals with ZEN is frequent, and hydrolytic detoxification with fungal lactonases has been explored. Here, we report the isolation of a bacterial strain, Rhodococcus erythropolis PFA D8-1, with ZEN hydrolyzing activity, cloning of the gene encoding α/β hydrolase ZenA encoded on the linear megaplasmid pSFRL1, and biochemical characterization of nine homologues. Furthermore, we report site-directed mutagenesis as well as structural analysis of the dimeric ZenARe of R. erythropolis and the more thermostable, tetrameric ZenAScfl of Streptomyces coelicoflavus with and without bound ligands. The X-ray crystal structures not only revealed canonical features of α/β hydrolases with a cap domain including a Ser-His-Asp catalytic triad but also unusual features including an uncommon oxyanion hole motif and a peripheral, short antiparallel β-sheet involved in tetramer interactions. Presteady-state kinetic analyses for ZenARe and ZenAScfl identified balanced rate-limiting steps of the reaction cycle, which can change depending on temperature. Some new bacterial ZEN lactonases have lower KM and higher kcat than the known fungal ZEN lactonases and may lend themselves to enzyme technology development for the degradation of ZEN in feed or food.

Gliomas: a reflection of temporal gliogenic principles.

The hijacking of early developmental programs is a canonical feature of gliomas where neoplastic cells resemble neurodevelopmental lineages and possess mechanisms of stem cell resilience. Given these parallels, uncovering how and when in developmental time gliomagenesis intersects with normal trajectories can greatly inform our understanding of tumor biology. Here, we review how elapsing time impacts the developmental principles of astrocyte (AS) and oligodendrocyte (OL) lineages, and how these same temporal programs are replicated, distorted, or circumvented in pathological settings such as gliomas. Additionally, we discuss how normal gliogenic processes can inform our understanding of the temporal progression of gliomagenesis, including when in developmental time gliomas originate, thrive, and can be pushed towards upon therapeutic coercion.

Exploring graded profiles of hippocampal atrophy along the anterior-posterior axis in semantic dementia and Alzheimer’s disease

Mounting evidence indicates marked hippocampal degeneration in semantic dementia (SD) however, the spatial distribution of hippocampal atrophy profiles in this syndrome remains unclear. Using a recently developed parcellation approach, we extracted hippocampal volumes from four distinct subregions running from anterior to posterior along the longitudinal axis (anterior, intermediate rostral, intermediate caudal, and posterior). Volumetric differences in hippocampal subregions were compared between 21 SD, 24 matched Alzheimer’s disease (AD), and 27 healthy older Control participants. Despite comparable overall hippocampal volume loss, SD and AD groups diverged in terms of the magnitude of atrophy along the anterior-posterior axis of the hippocampus. Global hippocampal atrophy was observed in AD, with no discernible gradation or lateralisation. In contrast, SD patients displayed graded bilateral hippocampal atrophy, most pronounced on the left-hand side, and concentrated in anterior relative to posterior subregions. Finally, we found preliminary evidence that disease-specific vulnerability along the anterior-posterior axis of the hippocampus was associated with canonical clinical features of these syndromes.

Improving Hand Gesture Recognition Robustness to Dynamic Posture Variations by Multimodal Deep Feature Fusion.

Surface electromyography (sEMG), a human-machine interface for gesture recognition, has shown promising potential for decoding motor intentions, but a variety of nonideal factors restrict its practical application in assistive robots. In this paper, we summarized the current mainstream gesture recognition strategies and proposed a gesture recognition method based on multimodal canonical correlation analysis feature fusion classification (MCAFC) for a nonideal condition that occurs in daily life, i.e., posture variations. The deep features of the sEMG and acceleration signals were first extracted via convolutional neural networks. A canonical correlation analysis was subsequently performed to associate the deep features of the two modalities. The transformed features were utilized as inputs to a linear discriminant analysis classifier to recognize the corresponding gestures. Both offline and real-time experiments were conducted on eight non-disabled subjects. The experimental results indicated that MCAFC achieved an average classification accuracy, average motion completion rate, and average motion completion time of 93.44%, 94.05%, and 1.38 s, respectively, with multiple dynamic postures, indicating significantly better performance than that of comparable methods. The results demonstrate the feasibility and superiority of the proposed multimodal signal feature fusion method for gesture recognition with posture variations, providing a new scheme for myoelectric control.

Spatio-temporal information analytics based performance-driven industrial process monitoring framework with cloud–edge-device collaboration

Smart manufacturing in the context of Industry 4.0 presents new characteristics, such as large-scale, complex sub-processes cooperation, and integrated information management, which makes comprehensive performance-driven process monitoring difficult to be achieved in practice. Cloud–edge-device collaboration brings new perspectives for modern industries. This paper presents a performance-driven process monitoring framework in cloud–edge-device collaborative architecture, including a spatio-temporal information analytics based method and its application to a hot strip mill process (HSMP). Firstly, an integrated performance-driven process monitoring framework is proposed, where different monitoring tasks are deployed in the device, edge, and cloud layers, respectively. Secondly, a new performance-related spatio-temporal information analytics based fault detection and localization method is developed. In detail, temporal kernel canonical correlation analysis (CCA) is employed to extract the canonical correlation features with nonlinearities in the temporal domains, and spatial CCA is designed to form the spatial features. Based on the spatio-temporal features, the equipment operation condition monitoring model is developed in the device layer for real-time fault localization, and the process monitoring model is deployed in the edge for fault detection. Furthermore, to give a high-level evaluation of the operating status of the process, a qualitative trend analysis based operation risks evaluation model is deployed in the cloud. Different from the traditional architectures, the data processing capability of each layer is fully utilized in the proposed one, and the function is relevant to the enterprise management system. It provides a topological basis with clear priorities for subsequent process regulation and optimization. Finally, an actual HSMP is introduced to testify the performance of the framework. From the results, the fault detection rates are improved in comparison with traditional methods, and the fault localization results are consistent with the actual situations.

PATH-12. CONTEMPORARY MOLECULAR LANDSCAPE, SURVIVAL, AND PROGNOSTIC FACTORS IN OVER 4,000 GLIOMAS

Abstract INTRODUCTION Molecular glioma classification and advances in treatment modalities have expanded therapeutic options for patients. We sought to capture the genomic landscape, prognostic features, and contemporary outcomes of gliomas. METHODS We assembled patients from TCGA (n=770) and multi-institutional datasets (n=3,546) with somatic mutations and copy number/structural variants. All gliomas were classified using molecular definitions (WHO 2021/cIMPACT-NOW). We identified correlations between genes through permutations testing and prognostic features through multivariate cox models with backwards elimination. RESULTS We analyzed 4,316 patients (median age 52yrs, 41% female), including 2,155 glioblastoma, 1,199 IDH1/2-mutant astrocytoma, 531 oligodendroglioma, and 343 other IDH1/2-wiltype gliomas. Molecular classification shifted 27.2% of gliomas from their original histopathologic designation. Canonical alterations categorized glioma subtypes, showing unique correlations with clinical features and mutual exclusivity of alterations in tumorigenic pathways. 2,433 patients had clinical outcomes: 1,296 glioblastomas, 584 IDH1/2-mutant astrocytoma, and 327 oligodendrogliomas. Patients from contemporary institutional cohorts had improved overall survival compared to TCGA patients: glioblastoma (non-TCGA:17.9mo,TCGA:15.0mo,p&amp;lt; 0.0001), IDH1/2-mutant astrocytoma (non-TCGA:180mo,TCGA: 87.9mo,p=0.0002), and oligodendroglioma (non-TCGA: not reached,TCGA:135mo,p&amp;lt; 0.0001). In contemporary cohorts, median survival in grade 2-3 IDH1/2-mutant astrocytoma (180.3mo) was double that of grade 4 (75.4mo, p&amp;lt; 0.0001). In GBM and oligodendrogliomas, patients &amp;gt;65yrs had worse outcomes than patients 20-64yrs (p&amp;lt; 0.001). In glioblastoma, age (HR:1.03), CDKN2A/B homozygous deletion (HR:1.22), and NF1 alterations (HR:1.31) were negatively prognostic. Chemotherapy (HR:0.64), MGMT-methylation (HR:0.44), 19q-gain (HR:0.70), and non-TCGA cohort (HR:0.54,HR:0.34) were positively prognostic. In IDH1/2-mutant astrocytoma, CDKN2A/B homozygous deletion (HR:2.75), CCND2 alteration (HR:2.89), EGFR amplification (HR:2.93), PDGFRA alteration (HR:2.87), 9p-loss (HR:3.09), and 10q-loss (HR:1.99) were negatively prognostic; white race was the only prognostically positive feature (HR:0.35). CONCLUSIONS Overall survival in gliomas has improved over time. We corroborated canonical features and identified new prognostic features that are subtype-specific. The unique molecular profiles across glioma subtypes provide insight into biological drivers that influence heterogenous clinical outcomes.

Abstract 18799: Edn1 is a Disease-Specific Marker in Endothelial Cells During Atherosclerosis

Introduction: Coronary artery disease (CAD) is the leading cause of mortality in the United States. Multiple cell types contribute to the atherosclerotic plaques causing CAD, influencing its growth and propensity to rupture. Endothelial-to-mesenchymal transition (EndMT), the process by which endothelial cells (ECs) acquire characteristics of mesenchymal cells and loose canonical endothelial features, is correlated with an unstable plaque phenotype, although this transition remains poorly characterized. Hypothesis: A specific population of ECs may undergo EndMT, potentially contributing to the progression of atherosclerosis. Methods: We induced endothelial-specific lineage-tracing in Tg Cdh5-CreERT2 , ApoE -/- mice, followed by 16 weeks of high-fat diet (HFD) to produce atherosclerosis. Aortic roots were collected from male and female disease-condition animals (n=13) and a baseline cohort that was not fed HFD (n=6). Single cell RNA sequencing was performed and analyzed using the Seurat package. RNAscope staining of transverse sections (n=10 per genotype per sex) was performed to characterize the lesion. Results: We identified multiple endothelial subtypes within the aortic root. One population, characterized by the marker Klk10, appears to give rise to a disease-specific population characterized by expression of Edn1. Upstream regulator analysis of differentially expressed genes between Edn1+ and Klk10+ populations predict this EC transition to be driven by EndMT-associated transcription regulators including SNAI2, TWIST2, STAT3, SNAI1, YAP1, and TEAD2. This analysis also predicted upregulation of pulmonary fibrosis idiopathic signaling, wound healing signaling, pathogen induced cytokine storm signaling, and hepatic fibrosis signaling pathways. This EndMT process, characterized by a single, linear trajectory, was the only disease-associated EC transition state identified in the atherosclerotic aortic root. Conclusions: We identified ECs undergoing EndMT in a mouse model of atherosclerosis and determined that this transition is the primary EC cell state transition during disease. We localized this process in situ in the atherosclerotic lesion and identified potential key transcriptional drivers of this process.

The transcriptome of the entomopathogenic fungus Culicinomyces clavisporus contains an ortholog of the insecticidal ribotoxin Hirsutellin.

The entomopathogenic fungus Culicinomyces clavisporus is known to infect and kill mosquito larvae and therefore has been seen as a potential biological control agent against disease vector mosquitoes. Whereas most fungal entomopathogens infect hosts by penetrating the external cuticle, C. clavisporus initiates infection through ingestion (per os). This unique infection strategy suggests that the C.clavisporus genome may be mined for novel pathogenicity factors with potential for vector control. To this end, an Isoseq-based transcriptome analysis was initiated, and resulted in a total of 3,512,145 sequences, with an average length of 1,732 bp. Transcripts assembly and annotation suggested that the C. clavisporus transcriptome lacked the cuticle-degrading proteins that have been associated with other entomopathogenic fungi, supporting the per os pathogenicity process. Furthermore, mining of the sequence data unexpectedly revealed C. clavisporus transcripts homologous to the Hirsutellin toxin. Comparative sequence analyses indicated that the C. clavisporus Hirsutellin predicted protein has retained the canonical molecular features that have been associated with the ribotoxic and insecticidal properties of the original toxin isolated from Hirsutella thompsonii. The identification of an Hirsutellin ortholog in C. clavisporus was supported by phylogenetic analyses demonstrating that Culicinomyces and Hirsutella were closely related genera in the Ophiocordycipitaceae family. Validation of the mosquitocidal activity of this novel C. clavisporus protein has yet to be performed but may help position Hirsutellin orthologs as prime candidates for the development of alternative biocontrol approaches complementing the current toolbox of vector mosquito management strategies.

Canonical features of the Synodal and Soviet periods: the problems of episcopal powers

Canonical features of the Synodal and Soviet periods: the problems of episcopal powers

Cleavage kinetics of human mitochondrial RNaseP and contribution of its non-nuclease subunits.

RNaseP is the endonuclease responsible for the 5' processing of precursor tRNAs (pre-tRNAs). Unlike the single-subunit protein-only RNaseP (PRORP) found in plants or protists, human mitochondrial RNaseP is a multi-enzyme assembly that in addition to the homologous PRORP subunit comprises a methyltransferase (TRMT10C) and a dehydrogenase (SDR5C1) subunit; these proteins, but not their enzymatic activities, are required for efficient pre-tRNA cleavage. Here we report a kinetic analysis of the cleavage reaction by human PRORP and its interplay with TRMT10C-SDR5C1 including 12 different mitochondrial pre-tRNAs. Surprisingly, we found that PRORP alone binds pre-tRNAs with nanomolar affinity and can even cleave some of them at reduced efficiency without the other subunits. Thus, the ancient binding mode, involving the tRNA elbow and PRORP's PPR domain, appears basically retained by human PRORP, and its metallonuclease domain is in principle correctly folded and functional. Our findings support a model according to which the main function of TRMT10C-SDR5C1 is to direct PRORP's nuclease domain to the cleavage site, thereby increasing the rate and accuracy of cleavage. This functional dependence of human PRORP on an extra tRNA-binding protein complex likely reflects an evolutionary adaptation to the erosion of canonical structural features in mitochondrial tRNAs.