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Li, C.

Publications and source records attributed to Li, C..

At least 505 records · Page 28Linked to original sources

Deep learning based genomic breeding of pest-resistant grapevine

Crop pests have profoundly deleterious effects on crop yield and food security. However, conventional pest control depends heavily on the utilization of insecticides, which develops strong pesticide resistance and concerns of food safety. Crop and their wild relatives display diverse levels of pest resistance, indicating the feasibility for breeding of pest-resistant crop varieties. In this study, we integrate deep learning (DL)/machine learning (ML) algorithms, plant phenomics and whole genome sequencing (WGS) data to conduct genomic selection (GS) of pest-resistance in grapevine. We employ deep convolutional neural networks (DCNN) to accurately calculate the severity of damage by pests on grape leaves, which achieves a classification accuracy of 95.3% (Visual Geometry Group 16, VGG16, for binary trait) and a correlation coefficient of 0.94 in regression analysis (DCNN with Pest Damage Score, DCNN-PDS, for continuous trait). We apply DL models to predict and integrate phenotype (both binary and continuous) along with WGS data from 231 grape accessions, conducting Genome-Wide Association Studies (GWAS). This analysis detects a total of 69 QTLs, encompassing 139 candidate genes involved in pathways associated with pest resistance, including jasmonic acid (JA), salicylic acid (SA), ethylene, and other related pathways. Furthermore, through the combination with transcriptome data, we identify specific pest-resistant genes, such as ACA12 and CRK3, which play distinct roles in resisting herbivore attacks. Machine learning-based GS demonstrates a high accuracy (95.7%) and a strong correlation (0.90) in predicting the leaf area damaged by pests as binary and continuous traits in grapevine, respectively. In general, our study highlights the power of DL/ML in plant phenomics and GS, facilitating genomic breeding of pest-resistant grapevine.

plant biology↗

The Kv2.2 channel mediates the inhibition of Prostaglandin E2 on glucose-stimulated insulin secretion in pancreatic β/-cells

Prostaglandin E2 (PGE2) is an endogenous inhibitor of glucose-stimulated insulin secretion (GSIS) and plays an important role in pancreatic {beta}-cell dysfunction in type 2 diabetes mellitus (T2DM). This study aimed to explore the underlying mechanism by which PGE2 inhibits GSIS. Our results showed that PGE2 inhibited Kv2.2 channels via increasing PKA activity in HEK293T cells overexpressed with Kv2.2 channels. Point mutation analysis demonstrated that S448 residue was responsible for the PKA-dependent modulation of Kv2.2. Furthermore, the inhibitory effect of PGE2 on Kv2.2 was blocked by EP2/4 receptor antagonists, while mimicked by EP2/4 receptor agonists. The immune fluorescence results showed that EP1-EP4 receptors are expressed in both mouse and human {beta}-cells. In INS-1(832/13) {beta}-cells, PGE2 inhibited voltage-gated potassium currents and electrical activity through EP2/4 receptors and Kv2.2 channels. Knockdown of Kv2.2 reduced the action potential firing frequency and alleviated the inhibition of PGE2 on GSIS in INS-1(832/13) {beta}-cells. PGE2 impaired glucose tolerance in wild-type mice but did not alter glucose tolerance in Kv2.2 knockout mice. Knockout of Kv2.2 reduced electrical activity, GSIS and abrogated the inhibition of PGE2 on GSIS in mouse islets. In conclusion, we have demonstrated that PGE2 inhibits GSIS in pancreatic {beta}-cells through the EP2/4-Kv2.2 signaling pathway. The findings highlight the significant role of Kv2.2 channels in the regulation of {beta}-cell repetitive firing and insulin secretion, and contribute to the understanding of the molecular basis of {beta}-cell dysfunction in diabetes.

physiology↗

eATP/P2X7R axis drives nanoparticle induced neutrophil recruitment in the pulmonary microcirculation

Exposure to nanoparticles (NPs) is frequently associated with adverse cardiovascular effects. In contrast, NPs in nanomedicine hold great promise for precise lung-specific drug delivery, especially considering the extensive pulmonary capillary network that facilitates interactions with bloodstream-suspended particles. Therefore, exact knowledge about interactions and effects of engineered NPs with the pulmonary microcirculation are instrumental for future application of this technology in patients. To unravel the real-time dynamics of intravenously delivered NPs and their effects in the pulmonary microvasculature, we employed intravital microscopy of the mouse lung. PEG amine-modified quantum dots (aQDs) with a low potential for biomolecule and cell interactions and carboxyl-modified quantum dots (cQDs) with a high interaction potential were used, representing two different NP subtypes. Only aQDs triggered rapid neutrophil recruitment in microvessels and their subsequent recruitment to the alveolar space. Application of specific inhibitors revealed that the aQDs induced neutrophil recruitment was linked to cellular degranulation, TNF-, and DAMP release into the circulation, particularly extracellular ATP (eATP). Stimulation of the ATP-gated P2X7R induced the expression of E-selectin on microvascular endothelium with the subsequent E-selectin depended neutrophilic immune response. Leukocyte integrins (LFA-1 and MAC-1) mediated adhesion and reduction in neutrophil crawling velocity on the vascular surface. In summary, this study unravels the complex cascade of neutrophil recruitment during NP-induced sterile inflammation. Thereby we demonstrate novel adverse effects for NPs in the pulmonary microcirculation and provide critical insights for optimizing NP-based drug delivery and therapeutic intervention strategies, to ensure their efficacy and safety in clinical applications. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=132 SRC="FIGDIR/small/584398v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@d10acborg.highwire.dtl.DTLVardef@1bbfe7org.highwire.dtl.DTLVardef@1d3e415org.highwire.dtl.DTLVardef@2328de_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

Cdon is required for organ Left-Right patterning via regulating DFCs migration and the sequential ciliogenesis

Cdon and boc are members of the cell adhesion molecule subfamily III Ig/fibronectin. Although they were reported to be involved in muscle and neural development at late developmental stage, while their early roles in embryonic development are unknown. Here we discovered that zebrafish cdon but not boc was expressed in dorsal forerunner cells (DFCs) and epitheliums of Kupffers vesicle (KV), implying the possible role of cdon in organ LR patterning. Further data showed that the liver and heart LR patterning was disturbed in cdon morphants and cdon mutants. Mechanically, we found that cdon loss of function led to dispersed DFCs migration, smaller KV and defective ciliogenesis, which resulting in randomized Nodal/spaw signaling and the sequential organ LR patterning defect. Finally, predominant distribution of a cdon MO in DFCs led to defects in DFCs migration, KV morphogenesis/ciliogenesis, Nodal/spaw signaling and organ LR asymmetry, being similar to those in cdon morphants and cdon-/- embryos, indicating a cell-autonomous role of cdon in regulating KV formation and ciliogenesis during LR patterning. In conclusion, our data demonstrated that, during gastrulation stage and early somitogenesis stage, cdon is required for proper DFCs migration, KV formation and ciliogenesis, thus playing an important role in setting up organ LR asymmetry.

developmental biology↗

High-throughput Screening of Compounds against Autoluminescent Nonreplicating Mycobacterium tuberculosis under Diverse Conditions

The screening of new anti-mycobacterial chemicals is primarily focused on inhibiting the active growing bacteria. However, a major challenge in tuberculosis control is the ability of Mycobacterium tuberculosis to enter a nonreplicating state for extended periods, rendering it resistant to many clinical drugs and complicating eradication efforts. Existing low-oxygen-recovery assays designed for screening compounds targeting nonreplicating M. tuberculosis have limitations, including the colony-forming unit counting for non-luminous M. tuberculosis and the instability of the free plasmid carrying luxAB genes in luminescent M. tuberculosis, along with exogenous substrate requirements for light producing. Moreover, these assays fail to accurately replicate the growth conditions of nonreplicating M. tuberculosis in vitro, thus resulting in less convincing results. To address these challenges, we have developed an autoluminescence-based, cholesterol-enriched culture evaluation model to assess 17 anti-tuberculosis drugs of different classes against nonreplicating M. tuberculosis. Our findings indicate that the relative light unit, measured in real-time, serves as a reliable surrogate marker for colony-forming unit, which typically becomes available one month later. This suggests the utility of our model for the rapid determination of drug susceptibility dynamically. The autoluminescent M. tuberculosis, harbouring luxCDABE gene cluster within its genome, can emit blue-green light stably and autonomously without requiring an external substrate supplement. The minimal inhibitory concentrations of all the drugs tested under anaerobic conditions are significantly different from that detected in aerobic environment. Our model allows for rapid, precise, and efficient assessment of drug activity under anaerobic conditions, thereby enabling a more comprehensive evaluation of anti-mycobacterial efficacy. Overall, our model represents a significant advancement in anti-tuberculosis drug discovery and pharmaceutical development.

microbiology↗

Spatiotemporal regulation of Pseudorabies Virus Thymidine kinase UL23 by post-translational modification

Post-translational modification plays a significant role in the interaction between viruses and their hosts. The pseudorabies virus (PRV) is a highly contagious herpesvirus that affects the central nervous system and respiratory tract of swine. However, the role of post-translational modifications, including Ubiquitination and SUMOylation, in host and PRV interplays is poorly understood. Here we examined the SUMO modification of PRV proteins and revealed that the PRV thymidine kinase UL23 can undergo SUMO modification. Bioinformatic analysis suggested four potential modification sites for UL23. Site-directed mutagenesis indicates that SUMO modification occurs at sites K242 and K267 as the wild type localizes in the nucleus while the mutants localize in the cytoplasm. Subsequently, polyclonal antibodies against mouse derived UL23 were employed to reveal that wild type UL23 was mainly located in the nucleus during PRV infection. Co-expression of UL23 with SUMO deconjugating enzymes showed that SENP1/2 inhibited the nuclear import of UL23. Whereas SUMO modification significantly impacted the localization of UL23, it did not detectably affect its stability.

cell biology↗

Feature-independent Encoding of Visual Salience inthe Mouse Superior Colliculus

Detecting conspicuous stimuli in a visual scene is crucial for animal survival, yet it remains debated how the brain encodes visual saliency. Here we investigate how visual saliency is represented in the superficial superior colliculus (sSC) of awake mice using two-photon calcium imaging. We report on a preference-independent saliency map in the sSC. Specifically, salient stimuli evoke stronger responses in both excitatory and inhibitory neurons compared to uniform stimuli, with similar encoding patterns observed in both neuron types. The largest response occurs when a salient stimulus is positioned at the receptive field center, with contextual effects extending [~]40{degrees} away from the center. The response amplitude correlates well with the saliency strength of stimuli and is not influenced by the orientation or motion direction preferences of neurons. However, saliency encoding does depend on specific visual features. Furthermore, neurons involved in saliency encoding exhibit weak orientation or direction selectivity, suggesting a complementary relationship between the saliency map and the feature map.

neuroscience↗

Comparison of a novel potentiator of CFTR channel activity to ivacaftor in ameliorating mucostasis caused by cigarette smoke in primary human bronchial airway epithelial cells

BackgroundCystic Fibrosis causing mutations in the gene CFTR, reduce the activity of the CFTR channel protein, and leads to mucus aggregation, airway obstruction and poor lung function. A role for CFTR in the pathogenesis of other muco-obstructive airway diseases such as Chronic Obstructive Pulmonary Disease (COPD) has been well established. The CFTR modulatory compound, Ivacaftor (VX-770), potentiates channel activity of CFTR and certain CF-causing mutations and has been shown to ameliorate mucus obstruction and improve lung function in people harbouring these CF-causing mutations. A pilot trial of Ivacaftor supported its potential efficacy for the treatment of mucus obstruction in COPD. These findings prompted the search for CFTR potentiators that are more effective in ameliorating cigarette-smoke (CS) induced mucostasis. MethodsA novel small molecule potentiator (SK-POT1), previously identified in CFTR binding studies, was tested for its activity in augmenting CFTR channel activity using patch clamp electrophysiology in HEK-293 cells, a fluorescence-based assay of membrane potential in Calu-3 cells and in Ussing chamber studies of primary bronchial epithelial cultures. Addition of cigarette smoke extract (CSE) to the solutions bathing the apical surface of Calu-3 cells and primary bronchial airway cultures was used to model COPD. Confocal studies of the velocity of fluorescent microsphere movement on the apical surface of CSE exposed airway epithelial cultures, were used to assess the effect of potentiators on CFTR-mediated mucociliary movement. ResultsWe showed that SK-POT1, like VX-770, was effective in augmenting the cyclic AMP-dependent channel activity of CFTR. SK-POT-1 enhanced CFTR channel activity in airway epithelial cells previously exposed to CSE and ameliorated mucostasis on the surface of primary airway cultures. ConclusionTogether, this evidence supports the further development of SK-POT1 as an intervention in the treatment of COPD.

physiology↗

Chlomito: a novel tool for precise elimination of organelle genome contamination in nuclear genome assemblies

Accurate genome assemblies are crucial for understanding biological evolution, mechanisms of disease, and biodiversity. However, contamination from organelle genomes in nuclear genome analyses often leads to inaccuracies and unreliability in results. To address this issue, we developed a tool named Chlomito, which employs innovative algorithms to precisely identify and eliminate organelle genome contamination sequences from nuclear genome assemblies. Compared to conventional approaches, Chlomito can not only detect and eliminate organelle sequences but also effectively distinguish true organelle sequences from those transferred into the nucleus via horizontal gene transfer. To evaluate the accuracy of Chlomito, we conducted tests using sequencing data from Plum and Mango. The results confirmed that Chlomito can accurately detect contigs originating from the organelle genome, and the identified contigs covered most regions of the organelle reference genomes, demonstrating its efficiency and precision in comprehensively recognizing organelle genome sequences. Additionally, for user convenience, we packaged this method into a Docker image, simplifying the data processing workflow. Overall, Chlomito provides a highly efficient and accurate method for identifying and removing contigs derived from organelle genomes in genomic assembly data, thereby contributing to the improvement of genome assembly quality and advancing research in genomics and evolutionary biology.

bioinformatics↗

Dark-based Optical Sectioning assists Background Removal in Fluorescence Microscopy

A fundamental challenge in fluorescence microscopy is the defocused background caused by scattering light, optical aberration, or limited axial resolution. Severe defocus backgrounds will submerge the in-focus information and cause artifacts in the following processing. Here, we leverage a priori knowledge about dark channels of biological structures and dual frequency separation to develop a single-frame defocus removal algorithm. It stably improves the signal-to-background ratio and structural similarity index measure of images by approximately 10-fold, and recovers in-focus signal with 85% accuracy, even when the defocus background is 50 times larger than in-focus information. Our Dark-based optical sectioning approach (Dark sectioning) is fully compatible with various microscopy techniques, such as wide-filed microscopy, polarized microscopy, laser-scanning / spinning-disk confocal microscopy, stimulated emission depletion microscopy, lightsheet microscopy, and light-field microscopy. It also complements reconstruction or processing algorithms such as deconvolution, structure illumination microscopy, and super-resolution optical fluctuation imaging.

bioinformatics↗

Deep learning modeling of ribosome profiling reveals regulatory underpinnings of translatome and interprets disease variants

Gene expression involves transcription and translation. Despite large datasets and increasingly powerful methods devoted to calculating genetic variants effects on transcription, discrepancy between mRNA and protein levels hinders the systematic interpretation of the regulatory effects of disease-associated variants. Accurate models of the sequence determinants of translation are needed to close this gap and to interpret disease-associated variants that act on translation. Here, we present Translatomer, a multimodal transformer framework that predicts cell-type-specific translation from mRNA expression and gene sequence. We train Translatomer on 33 tissues and cell lines, and show that the inclusion of sequence substantially improves the prediction of ribosome profiling signal, indicating that Translatomer captures sequence-dependent translational regulatory information. Translatomer achieves accuracies of 0.72 to 0.80 for de novo prediction of cell-type-specific ribosome profiling. We develop an in silico mutagenesis tool to estimate mutational effects on translation and demonstrate that variants associated with translation regulation are evolutionarily constrained, both within the human population and across species. Notably, we identify cell-type-specific translational regulatory mechanisms independent of eQTLs for 3,041 non-coding and synonymous variants associated with complex diseases, including Alzheimers disease, schizophrenia, and congenital heart disease. Translatomer accurately models the genetic underpinnings of translation, bridging the gap between mRNA and protein levels, and providing valuable mechanistic insights toward mapping "missing regulation" in disease genetics.

genomics↗

Directed biomechanical compressive forces enhance fusion efficiency in model placental trophoblast cultures

The syncytiotrophoblast is a multinucleated structure that arises from fusion of mononucleated cytotrophoblasts, to sheath the placental villi and regulate transport across the maternal-fetal interface. Here, we ask whether the dynamic mechanical forces that must arise during villous development might influence fusion, and explore this question using in vitro choriocarcinoma trophoblast models. We demonstrate that mechanical stress patterns arise around sites of localized fusion in cell monolayers, in patterns that match computational predictions of villous morphogenesis. We then externally apply these mechanical stress patterns to cell monolayers and demonstrate that equibiaxial compressive stresses (but not uniaxial or equibiaxial tensile stresses) enhance expression of the syndecan-1 marker of fusion. These findings suggest that the mechanical stresses that contribute towards sculpting the placental villi may also impact fusion in the developing tissue. We then extend this concept towards 3D cultures and demonstrate that fusion can be enhanced by applying low isometric compressive stresses to spheroid models, even in the absence of an inducing agent. These results indicate that mechanical stimulation is a potent activator of cellular fusion, suggesting novel avenues to improve experimental reproductive modelling, placental tissue engineering, and understanding disorders of pregnancy development.

biophysics↗

Exploring the conformational space of protein-protein complex with transformer-based generative model

Protein-protein interactions are the basis of many protein functions, and understanding the contact and conformational changes of protein-protein interactions is crucial for linking protein structure to biological function. Although difficult to detect experimentally, molecular dynamics (MD) simulations are widely used to study the conformational ensembles and dynamics of protein-protein complexes, but there are significant limitations in sampling efficiency and computational costs. In this study, a generative neural network was trained on protein-protein complex conformations obtained from molecular simulations to directly generate novel conformations with physical realism. We demonstrated the use of a deep learning model based on the transformer architecture to explore the conformational ensembles of protein-protein complexes through MD simulations. The results showed that the learned latent space can be used to generate unsampled conformations of protein-protein complexes for obtaining new conformations complementing pre-existing ones, which can be used as an exploratory tool for the analysis and enhancement of molecular simulations of protein-protein complexes.

bioinformatics↗

Augmentation of DNA exonuclease TREX1 in macrophages as a therapy for cardiac ischemic injury

Noncoding RNAs (ncRNAs) are increasingly recognized as bioactive. Here we report the development of TY1, a synthetic ncRNA bioinspired by a naturally-occurring human small Y RNA with immunomodulatory properties. TY1 upregulates TREX1, an exonuclease that rapidly degrades cytosolic DNA. In preclinical models of myocardial infarction (MI) induced by ischemia/reperfusion, TY1 reduced scar size. The cardioprotective effect of TY1 was abrogated by prior depletion of macrophages and mimicked by adoptive transfer of macrophages exposed either to TY1 or TREX1. Inhibition of TREX1 in macrophages blocked TY1 cardioprotection. Consistent with a central role for TREX1, TY1 attenuated DNA damage in the post-MI heart. This novel mechanism--pharmacologic upregulation of TREX1 in macrophages--establishes TY1 as the prototype for a new class of ncRNA drugs with disease-modifying bioactivity. One Sentence SummaryUpregulation of three prime exonuclease, TREX1, in macrophages enhances tissue repair post myocardial infarction.

molecular biology↗

Episodic recruitment of attractor dynamics in frontal cortex reveals distinct mechanisms for forgetting and lack of cognitive control in short-term memory

Short-term memory (STM) is prone to failure, especially during prolonged memory maintenance or under limited cognitive control. Despite predictive mechanistic frameworks based on persistent neural activity and attractor states, a direct assessment of network dynamics during multifactorial STM failure is still missing. We addressed this in a delayed-response task where mice maintained a prospective response during a long variable delay. Mice behavior episodically switched between a task-engaged state described by an attractor model, and a task-disengaged state purely determined by previous choices. During task engagement, the anterolateral motor cortex (ALM) showed delay persistent activity stably encoding correct choices, whereas the encoding reversed during the delay in error trials. In contrast, in task-disengaged phases ALM showed no clear traces of attractor dynamics and instead exhibited enhanced synchrony at [~] 4-5Hz. Thus, ALM switches between distinct error-generating dynamics: in control-capable trials, transitions between memory attractors cause forgetting errors, whereas non-memory errors are caused by the dissociation of ALM during the mnemonic period reflecting the lack of cognitive control.

neuroscience↗

Dysregulation of mitochondrial function by PLK1-mediated PDHA1 phosphorylation promotes Cr(VI)-associated lung cancer progression

Hexavalent chromium (Cr(VI)) is a class I environmental carcinogen known to induce lung epithelial cell transformation and promote lung cancer progression through alterations in the cell cycle and cellular energy metabolism. In this study, we investigated the role of polo-like kinase 1 (PLK1) in Cr(VI)-transformed (CrT) bronchial epithelial cells (BEAS-2B) and found that PLK1 expression was significantly upregulated in CrT cells, leading to impaired mitochondrial function and enhanced cell proliferation both in vitro and in vivo. High levels of PLK1 in CrT cells resulted in decreased mitochondrial activity due to defective modulation of pyruvate dehydrogenase E1 subunit alpha 1 (PDHA1), which is crucial for pyruvate/Acetyl-CoA conversion and carbon influx into the tricarboxylic acid (TCA) cycle. Mechanistically, we demonstrated that PLK1 directly phosphorylates PDHA1 at T57, leading to E1 collapse and PDHA1 degradation via activation of mitophagy. These defects resulted in the inhibition of oxidative phosphorylation and reduction of mitochondrial superoxide generation, ultimately leading to suppression of mitochondrial-mediated apoptotic response. Our findings highlight the role of PLK1 in metabolic reprogramming during Cr(VI)-associated cancer progression, providing new insights and a potential therapeutic target to inhibit Cr(VI)-induced cancer development. Moreover, PLK1 inhibitors may also have the potential to increase chemo-sensitivity of cancer cells by restoring normal mitochondrial function, thereby mitigating drug resistance caused by mitochondrial dysfunction and hyperpolarization.

cancer biology↗

Adaptive diversification through structural variation in barley

Pangenomes are collections of annotated genome sequences of multiple individuals of a species. The structural variants uncovered by these datasets are a major asset to genetic analysis in crop plants. Here, we report a pangenome of barley comprising long-read sequence assemblies of 76 wild and domesticated genomes and short-read sequence data of 1,315 genotypes. An expanded catalogue of sequence variation in the crop includes structurally complex loci that have become hot spots of gene copy number variation in evolutionarily recent times. To demonstrate the utility of the pangenome, we focus on four loci involved in disease resistance, plant architecture, nutrient release, and trichome development. Novel allelic variation at a powdery mildew resistance locus and population-specific copy number gains in a regulator of vegetative branching were found. Expansion of a family of starch-cleaving enzymes in elite malting barleys was linked to shifts in enzymatic activity in micro-malting trials. Deletion of an enhancer motif is likely to change the developmental trajectory of the hairy appendages on barley grains. Our findings indicate that rapid evolution at structurally complex loci may have helped crop plants adapt to new selective regimes in agricultural ecosystems.

plant biology↗

Population genomics of the rice landrace Acuce reveals exceptional dynamics of immune receptors

In cultivated plants such as Oryza sativa, landraces harbour high levels of diversity, in sharp contrast with genetically uniform modern varieties. The Yuanyang terraces (China) are renowned for traditional farming involving landraces and low disease incidence. To understand the molecular basis of these resistance levels, we explored the genomic diversity of Acuce, one of the oldest landraces in the region. Based on whole-genome resequencing of over 200 Acuce plants, we evaluated the diversity of immunity and agronomical genes with respect to the rest of the genome. In parallel, we analysed the genetic basis of pathogen resistance and agronomical traits. Acuce exhibits high levels of diversity, reaching 38% of the worldwide levels. We uncovered an excess of diversity and signatures of directional selection associated with immunity genes, in contrast with agricultural traits. Furthermore, cultures of mixed genotypes exhibited superior performances for both pathogen resistance and agricultural traits. We showed that, within one single landrace, traditional farmer practices selected optimal agricultural traits while maintaining diversity enabling pathogen resistance. This study elucidates the complex interplay between genetic diversity, natural selection related to pathogens, and selection for agricultural traits within traditional landraces, providing insights into sustainable agricultural practices in diverse cropping systems.

genomics↗