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Biology subjects

Xu, H.

Publications and source records attributed to Xu, H..

At least 289 records · Page 16Linked to original sources

Smart squirrels use a mortise-tenon structure to fix nuts on understory twigs

Squirrels of temperate zones commonly store nuts or seeds under leaf litter, in hollow logs or even in holes in the ground; however, in humid rainforests, it is an evolutionary challenge for squirrels to hang elliptical or oblate nuts securely on trees to minimize germination or fungal infection. Here, we report a unique behaviour used by two species of small flying squirrels (Hylopetes phayrei electilis (G. M. Allen, 1925) and Hylopetes alboniger (Hodgson, 1870)) to cache nuts on Hainan Island. Squirrels intentionally carved grooves encircling ellipsoid nuts or distributed on the bottom of oblate nuts and used these grooves to fix nuts tightly between small twigs 0.1-0.6 cm in diameter and connected at angles of 25-40{degrees}. The resulting structures were similar to the mortise-tenon joint of ancient Chinese architecture. Cache sites were on small plants located 10-25 m away from the closest potentially nut-producing tree, a behaviour that likely deters discovery and consumption of the nuts by other animals. Their ability to shape individual nuts to store them more securely suggests it is a smart behavior, which is likely formed by the adaption to life in humid tropical rainforests to guarantee food supply and impacts the distribution of tree species.

ecology↗

GABAergic neuron-to-glioma synapses in diffuse midline gliomas

Pediatric high-grade gliomas are the leading cause of brain cancer-related death in children. High-grade gliomas include clinically and molecularly distinct subtypes that stratify by anatomical location into diffuse midline gliomas (DMG) such as diffuse intrinsic pontine glioma (DIPG) and hemispheric high-grade gliomas. Neuronal activity drives high-grade glioma progression both through paracrine signaling1,2 and direct neuron-to-glioma synapses3-5. Glutamatergic, AMPA receptor-dependent synapses between neurons and malignant glioma cells have been demonstrated in both pediatric3 and adult high-grade gliomas4, but neuron-to-glioma synapses mediated by other neurotransmitters remain largely unexplored. Using whole-cell patch clamp electrophysiology, in vivo optogenetics and patient-derived glioma xenograft models, we have now identified functional, tumor-promoting GABAergic neuron-to-glioma synapses mediated by GABAA receptors in DMGs. GABAergic input has a depolarizing effect on DMG cells due to NKCC1 expression and consequently elevated intracellular chloride concentration in DMG tumor cells. As membrane depolarization increases glioma proliferation3, we find that the activity of GABAergic interneurons promotes DMG proliferation in vivo. Increasing GABA signaling with the benzodiazepine lorazepam - a positive allosteric modulator of GABAA receptors commonly administered to children with DMG for nausea or anxiety - increases GABAA receptor conductance and increases glioma proliferation in orthotopic xenograft models of DMG. Conversely, levetiracetam, an anti-epileptic drug that attenuates GABAergic neuron-to-glioma synaptic currents, reduces glioma proliferation in patient-derived DMG xenografts and extends survival of mice bearing DMG xenografts. Concordant with gene expression patterns of GABAA receptor subunit genes across subtypes of glioma, depolarizing GABAergic currents were not found in hemispheric high-grade gliomas. Accordingly, neither lorazepam nor levetiracetam influenced the growth rate of hemispheric high-grade glioma patient-derived xenograft models. Retrospective real-world clinical data are consistent with these conclusions and should be replicated in future prospective clinical studies. Taken together, these findings uncover GABAergic synaptic communication between GABAergic interneurons and diffuse midline glioma cells, underscoring a tumor subtype-specific mechanism of brain cancer neurophysiology with important potential implications for commonly used drugs in this disease context.

neuroscience↗

Disruption of OsLAT5 is sufficient to endow rice tolerance to dihydropyridine herbicides at commercial application concentrations

Breeding non-selective herbicide-resistant crops is important constituent of weed management system in modern rice production. Non-selective dihydropyridine herbicide shares transporters with polyamine (PA), making construction of a dihydropyridine herbicide-resistant rice line possible by inactivating the PA transporter function via gene editing. Success depends on understanding substrate selection for homologues in the PA transporter family and amino acid sites that play critical roles. Here, OsLAT1 was mainly responsible for root uptake and root-to-shoot transport; whereas, OsLAT5 was more responsible for intracellular transport to chloroplasts. The oslat5 disruption line tolerated relevant concentrations, while oslat1 did not. Compared to GY11 wild type, plant height, 1000-grain weight, and spermidine, spermine, and putrescine content changes occurred in GY11-oslat5 lines, implying involvement of OsLAT5 in yield and quality regulation. OsLAT5P44F, P44Y and P44R showed declined dihydropyridine herbicide uptake but no spermidine and putrescine transport competence disruption in yeast, providing a candidate site for precisely editing in breeding a dihydropyridine herbicide-resistant rice cultivar without impairing rice yield and grain quality.

plant biology↗

A non-human primate model with Alzheimer's disease-like pathology induced by hippocampal overexpression of human tau

Alzheimers disease (AD) is one of the most burdening diseases of the century with no disease-modifying treatment yet. Non-human primates (NHPs) share genetic, anatomical and physiological similarities with humans, making them an ideal model for investigating the pathogenesis and therapeutics of AD. However, the applications of NHPs in AD research have been hindered by the paucity of spontaneous or induced monkey models for AD due to their long generation time, ethical considerations and technical challenges in making genetically modified monkeys. Here we developed an AD-like NHP model by overexpressing human tau in bilateral hippocampi of adult rhesus macaque monkeys. We evaluated the pathological features of these monkeys with immunostaining, cerebrospinal fluid (CSF) analysis, magnetic resonance imaging (MRI), positron emission tomography (PET) scan, and behavioral tests. We demonstrated that after hippocampal overexpression of human tau, the rhesus macaque monkeys displayed multiple pathological features of AD, including neurofibrillary tangle formation, neuronal loss, hippocampal atrophy, neuroinflammation, A{beta} clearance deficit, blood vessel damage and cognitive decline. This work establishes a human tau-induced AD-like NHP model that may facilitate mechanistic studies and therapeutic treatments for AD.

neuroscience↗

SurvivalML: an integrative platform for the discovery and exploration of prognostic models in multi-center cancer cohorts

Advances in multi-omics and big-data technologies have led to numerous prognostic signatures aimed at improving current clinicopathological staging systems. Due to the lack of reproducibility and independent confirmation, few signatures have been translated into clinical routine. As high-quality datasets accumulate, identifying robust signatures across multiple independent cohorts becomes possible. Nonetheless, inaccurate data retrieval, different versions of genome annotations, disparate expression distributions, difficult data cleaning, inconsistent clinical information, algorithm selection, and parameter tuning have impeded model development and validation in multi-center datasets. Hence, for the first time, we introduced SurvivalML (https://rookieutopia.com/app_direct/SurvivalML/), a web application for helping develop and validate prognostic models across multi-center datasets. SurvivalML included 37,325 samples (253 eligible datasets) with both transcriptome data and survival information from 21 cancer types, which were renewedly and uniformly re-annotated, normalized, and cleaned. This application provided 10 survival machine-learning algorithms for flexibly training models via tuning essential parameters online and delivered four aspects for model evaluation, including Kaplan-Meier survival analysis, time-dependent ROC, calibration curve, and decision curve analysis. Overall, we believe that SurvivalML can serve as an attractive platform for model discovery from multi-center datasets.

bioinformatics↗

BEST: a web application for comprehensive biomarker exploration on large-scale data in solid tumors

SummaryData mining from RNA-seq or microarray data has become an essential part of cancer biomarker exploration. Certain existing web servers are valuable and broadly utilized, but the meta-analysis of multiple datasets is absent. Most web servers only contain tumor samples from the TCGA database with only one cohort for each cancer type, which also means that the analysis results mainly derived from a single cohort are thin and unstable. Indeed, consistent performance across multiple independent cohorts is the foundation for an excellent biomarker. Moreover, many analytical functions researchers require remain adequately unmet by these tools. Thus, we introduce BEST (Biomarker Exploration for Solid Tumors), a web application for comprehensive biomarker exploration on large-scale data in solid tumors. BEST includes more than 50,000 samples of 27 cancer types. To ensure the comparability of genes between different sequencing technologies and the legibility of clinical traits, we re-annotated transcriptome data based on the GRCh38 patch 13 sequences and unified the nomenclature of clinical traits. BEST delivers fast and customizable functions, including clinical association, survival analysis, enrichment analysis, cell infiltration, immunomodulator, immunotherapy, candidate agents, and genomic alteration. Together, our web server provides multiple cleaned-up independent datasets and diverse analysis functionalities, helping unleash the value of current data resources. It is freely available at https://rookieutopia.com/. The bigger pictureBioinformatics web servers enable researchers without computational programming skills to conduct various bioinformatics analyses. However, most web servers only contain tumor samples from the TCGA database with only one cohort for each cancer type, which also means that the analysis results mainly derived from a single cohort are thin and unstable. Thus, we introduce BEST (Biomarker Exploration for Solid Tumors), a web application for comprehensive biomarker exploration on large-scale data in solid tumors. BEST includes more than 50,000 samples of 27 cancer types that have been uniformly re-annotated based on the GRCh38 patch 13 sequences, which ensures the comparability of genes between different sequencing technologies. BEST also offers prevalent functions including clinical association, survival analysis, enrichment analysis, cell infiltration, immunomodulator, immunotherapy, candidate agents, and genomic alteration. Together, BEST provides a curated database and innovative analytical pipelines to explore cancer biomarkers at high resolution.

genomics↗

Searching across-cohort relatives via encrypted genotype regression

Explicitly sharing individual level data in genomics studies has many merits comparing to sharing summary statistics, including more strict QCs, common statistical analyses, relative identification and improved statistical power in GWAS, but it is hampered by privacy or ethical constraints. In this study, we developed encG-reg, a regression approach that can detect relatives of various degrees based on encrypted genomic data, which is immune of ethical constraints. The encryption properties of encG-reg are based on the random matrix theory by masking the original genotypic matrix without sacrificing precision of individual-level genotype data. We established a connection between the dimension of a random matrix, which masked genotype matrices, and the required precision of a study for encrypted genotype data. encG-reg has false positive and false negative rates equivalent to sharing original individual level data, and is computationally efficient when searching relatives. We split the UK Biobank into their respective centers, and then encrypted the genotype data. We observed that the relatives estimated using encG-reg was equivalently accurate with the estimation by KING, which is a widely used software but requires original genotype data. In a more complex application, we launched a finely devised multi-center collaboration across 5 research institutes in China, covering 9 cohorts of 54,092 GWAS samples. encG-reg again identified true relatives existing across the cohorts with even different ethnic backgrounds and genotypic qualities. Our study clearly demonstrates that encrypted genomic data can be used for data sharing without loss of information or data sharing barrier. Author SummaryEstimating pairwise genetic relatedness within a single cohort is straightforward. However, in practice, related samples are often distributed across different cohorts, making it challenging to estimate inter-cohort relatedness. In this study, we propose a method called encrypted genotype regression (encG-reg), which provides an unbiased estimation of inter-cohort relatedness using encrypted genotypes. The genotype matrix of each cohort is masked by a random matrix, which acts similarly to a private key in a cryptographic scheme. This masking process produces encrypted genotypes, which are a projection of the original genotype matrix. We derive the expectation and particularly the sampling variance for encG-reg, the latter involves eighth-order moments calculation. encG-reg allows us to accurately identify relatedness across cohorts, even for large-scale biobank data. To demonstrate the efficacy of encG-reg, we verified it in a multi-ethnicity UK Biobank dataset comprising 485,158 samples. For this case, we successfully tracked down to the 1st-degree relatedness (such as full sibs and parent-offspring). Furthermore, we used encG-reg in a collaboration involving 9 Chinese cohorts, encompassing a total of 54,092 samples from 5 genomic centers. It is worth noting that if the number of effective markers is sufficient encG-reg has the potential to detect even more distant degrees of relatedness beyond what we demonstrated.

genetics↗

MAP4Ks inhibition promotes retinal neuron regeneration from Muumlller glia in adult mice

Mammalian Muller glia (MG) possess limited regenerative capacities. However, the intrinsic capacity of mammalian MG to transdifferentiate to generate mature neurons without transgenic manipulations remains speculative. Here we show that MAP4K4, MAP4K6 and MAP4K7, which are conserved Misshapen subfamily of ste20 kinases homologs, repress YAP activity in mammalian MG and therefore restrict their ability to be reprogrammed. However, by treating with a small molecule inhibitor of MAP4K4/6/7, mouse MG regain their ability to proliferate and enter into a retinal progenitor cell (RPC)-like state after NMDA-induced retinal damage; such plasticity was lost in YAP knockout MG. Moreover, spontaneous trans-differentiation of MG into retinal neurons expressing both amacrine and retinal ganglion cell (RGC) markers occurs after inhibitor withdrawal. Taken together, these findings suggest that MAP4Ks block the reprogramming capacity of MG in a YAP-dependent manner in adult mammals, which provides a novel avenue for the pharmaceutical induction of retinal regeneration in vivo.

neuroscience↗

Mechanism of dual pharmacological correction and potentiation of human CFTR

Cystic fibrosis (CF) is caused by mutations in a chloride channel called the human Cystic Fibrosis Transmembrane Conductance Regulator (hCFTR). We used cryo-EM global conformational ensemble reconstruction to characterize the mechanism by which the breakthrough drug VX445 (Elexacaftor) simultaneously corrects both protein-folding and channel-gating defects caused by CF mutations. VX445 drives hCFTR molecules harboring the gating-defective G551D mutation towards the open-channel conformation by binding to a site in the first transmembrane domain. This binding interaction reverses the usual pathway of allosteric structural communication by which ATP binding activates channel conductance, which is blocked by the G551D mutation. Our ensemble reconstructions include a 3.4 [A] non-native structure demonstrating that detachment of the first nucleotide-binding domain of hCFTR is directly coupled to local unfolding of the VX445 binding site. Reversal of this unfolding transition likely contributes to its corrector activity by cooperatively stabilizing NBD1 and the transmembrane domains of hCFTR during biogenesis. SummaryCryo-EM global conformational ensemble reconstruction has been used to characterize the mechanism-of-action of a breakthrough pharmaceutical that corrects fatal protein-folding and channel-gating defects in the human cystic fibrosis transmembrane conductance regulator (CFTR).

biophysics↗

Aerosolizable plasmid DNA dry powders engineered by thin-film freezing

This study was designed to test the feasibility of using thin-film freezing (TFF) to prepare aerosolizable dry powders of plasmid DNA (pDNA) for pulmonary delivery. Dry powders of pDNA formulated with mannitol/leucine (70/30, w/w) at various of drug loadings, solid contents, and solvents were prepared using TFF, their aerosol properties (i.e., mass median aerodynamic diameter (MMAD) and fine particle fraction (FPF)) determined, and selected powders were used for further characterization. Of the nine dry powders prepared, their MMAD values were about 1-2 mm, with FPF values (delivered) of 40-80%. The aerosol properties of the powders were inversely correlated with the pDNA loading and the solid content in the pDNA solution before thin-film freezing. Powders prepared with Tris-EDTA (TE) buffer or cosolvents (i.e., 1,4 dioxane or t-butanol in water), instead of water, showed slightly reduced aerosol properties. Ultimately, powders prepared with pDNA loading at 5% (w/w), 0.25% of solid content, with or without TE were selected for further characterization due to their overall good aerosol performance. The pDNA powders exhibited a porous matrix, crystalline structure, with a moisture content of <2% (w/w). Agarose gel electrophoresis confirmed the chemical integrity of the pDNA after it was subjected to TFF and after the TFF powder was actuated. A cell transfection study confirmed the activity of the pDNA after it was subjected to TFF. In conclusion, it is feasible to use TFF to produce aerosolizable pDNA dry powder for pulmonary delivery, while preserving the integrity and activity of the pDNA.

pharmacology and toxicology↗

Perturbation of mitochondrial Ca2+ homeostasis activates cross-compartmental proteostatic response in Arabidopsis

Mitochondrial Ca2+ (mtCa2+) homeostasis is essential to mitochondrial functions. However, how mtCa2+ homeostasis is achieved and the consequences of impaired mtCa2+ homeostasis in plants is poorly understood. Here, we demonstrate a critical role for mitochondrial Ca2+ uniporter (MCU) in the control of mtCa2+ uptake for mtCa2+ homeostasis in planta by characterizing MCU mutants and overexpressed plants. Impaired MCU-controlled mtCa2+ homeostasis (iMUCH) in gain-of-function and loss-of-function MCU plants causes the misregulation of mitochondrial gene expression that triggers mitonuclear protein imbalance. Transcriptome integrated with proteomics analysis reveal activation of multiple compartmental UPR gene expression and decrease of cytosolic translation with selective repression of ribosome and RNA modification protein synthesis upon iMUCH. Intriguingly, TOR signalling is not involved in cytosolic translational response to iMUCH, but the reduction of eIF phosphorylation is evident under iMUCH induced mitochondrial stress. Thus, our study unveils the essential functions of MCU proteins for mtCa2+ homeostasis, and the involvement of MCU-controlled mtCa2+ homeostasis in mitochondrial stress dependent regulation of protein synthesis for cellular proteostasis that is connected to plant growth and stress resistance.

plant biology↗

Bat pluripotent stem cells reveal unique entanglement between host and viruses

Bats have evolved features unique amongst mammals, including flight, laryngeal echolocation, and certain species have been shown to have a unique immune response that may enable them to tolerate viruses such as SARS-CoVs, MERS-CoVs, Nipah, and Marburg viruses. Robust cellular models have yet to be developed for bats, hindering our ability to further understand their special biology and handling of viral pathogens. To establish bats as new model study species, we generated induced pluripotent stem cells (iPSCs) from a wild greater horseshoe bat (Rhinolophus ferrumequinum) using a modified Yamanaka protocol. Rhinolophids are amongst the longest living bat species and are asymptomatic carriers of coronaviruses, including one of the viruses most closely related to SARS-CoV-2. Bat induced pluripotent stem (BiPS) cells were stable in culture, readily differentiated into all three germ layers, and formed complex embryoid bodies, including organoids. The BiPS cells were found to have a core pluripotency gene expression program similar to that of other species, but it also resembled that of cells attacked by viruses. The BiPS cells produced a rich set of diverse endogenized viral sequences and in particular retroviruses. We further validated our protocol by developing iPS cells from an evolutionary distant bat species Myotis myotis (greater mouse-eared bat) non-lethally sampled in the wild, which exhibited similar attributes to the greater horseshoe bat iPS cells, suggesting that this unique pluripotent state evolved in the ancestral bat lineage. Although previous studies have suggested that bats have developed powerful strategies to tame their inflammatory response, our results argue that they have also evolved mechanisms to accommodate a substantial load of endogenous viral sequences and suggest that the natural history of bats and viruses is more profoundly intertwined than previously thought. Further study of bat iPS cells and their differentiated progeny should advance our understanding of the role bats play as virus hosts, provide a novel method of disease surveillance, and enable the functional studies required to ascertain the molecular basis of bats unique traits.

developmental biology↗

Depletion of collagen IX alpha2 interferes osteochondral homeostasis of the knee joint which ultimately causing osteoarthritis-like articular cartilage damage

As one of the branched chains of Type IX collagen (Col9), Collagen IX alpha2 (Col92) has been reported to be associated with several orthopedic conditions. To probe the relationship between Col92 and knee osteoarthritis (KOA), we performed a systematic analysis of Col92-deficient (Col9-/-) mice using whole-mount skeletal staining, Micro-CT (CT), biomechanics, histomorphometry, immunohistochemistry (IHC), immunofluorescence (IF) and Enzyme-linked immunosorbent (Elisa). Although whole-mount skeletal staining displayed no difference in bone length and ossification between Col9-/- mice and wild-type (Col92+/+) mice at mid-gestation and adult stages, the knee joint exhibited dramatic discrepancies. Specifically, the subchondral bone (SCB) in the knee joint of Col9-/- mice became sparse and deformed in the early stage, with altered bone morphometric parameters, reduced load-bearing capacity, dysfunctional bone homeostasis (decreased osteogenesis capacity and elevated bone resorption capacity), diminished cartilage proteoglycans and disrupted cartilage extracellular matrix (ECM) anabolism and catabolism compared with the Col92+/+ mice. In the late stage, the cartilage degeneration in Col92-/- mice were particularly pronounced compared to Col92+/+ mice, as evidenced by severe cartilage destruction and a marked reduction in cartilage thickness and area. Overall, Col92 is essential for maintaining osteochondral homeostasis in the knee joint of mice, and the absence of this gene is accompanied by distinct sclerosis of the SCB and a reduction in load-bearing capacity; in the late stage, in the lack of SCB stress inhibition, excessive load is consistently exerted on the cartilage, ultimately leading to osteoarthritic-like articular cartilage damage. Hence, Col92 may serve as a potential candidate biomarker associated with KOA.

physiology↗

Chaperones Hsc70 and Hsp70 Play Distinct Roles in Bocaparvovirus Minute Virus of Canines Infection

Minute virus of canines (MVC) belongs to the genus Bocaparvovirus and reproduces rapidly in its permissive cells Walter Reed/3873D (WRD). The crosstalk between MVC and WRD is poorly characterized in terms of molecular requirements and mechanisms. Here, we identified two novel cellular proteins Hsc70 and Hsp70 that interact with both NS1 and VP2 via mass spectrometry (MS), co-immunoprecipitation (Co-IP) and confocal immunofluorescence assays (IFA). Hsp70 was upregulated upon MVC infection. Respective silencing of Hsc70 and Hsp70 led to contrasting results at nearly every stage of MVC life cycle, including virus entry, transcription, translation, replication and production. Strikingly, transfection with low and high dose of pFlag-Hsp70 contributed to opposing impacts on viral protein levels and virus production possibly through a ubiquitin-dependent manner, indicating that MVC is quite sensitive to the levels of Hsp70. Treatment with quercetin and VER155008, two Hsp70 family inhibitors, both significantly decreased viral replication and particle levels. Together, these results illustrated that both Hsc70 and Hsp70 are involved in MVC life cycle, and targeting to Hsp70 family may represent a novel anti-MVC mechanism.

molecular biology↗

Protease-independent production of poliovirus virus-like particles in Pichia pastoris: Implications for efficient vaccine development and insights into capsid assembly.

The production of enterovirus virus-like particles (VLPs) which lack the viral genome have great potential as vaccines for a number of diseases, such as poliomyelitis and hand, foot-and-mouth disease. These VLPs can mimic empty capsids, which are antigenically indistinguishable from mature virions, produced naturally during viral infection. Both in infection and in vitro, capsids and VLPs are generated by the cleavage of the P1 precursor protein by a viral protease. Here, using a stabilised poliovirus 1 (PV-1) P1 sequence as an exemplar, we show the production of PV-1 VLPs in Pichia pastoris in the absence of the potentially cytotoxic protease, 3CD, instead using the porcine teschovirus 2A (P2A) peptide sequence to terminate translation between individual capsid proteins. We compare this to protease-dependent production of PV-1 VLPs. Analysis of all permutations of the order of the capsid protein sequences revealed that only VP3 could be tagged with P2A and maintain native antigenicity. Transmission electron microscopy of these VLPs reveals the classic picornaviral icosahedral structure. Furthermore, these particles were thermostable above 37{degrees}C, demonstrating their potential as next generation vaccine candidates for PV. Finally, we believe the demonstration that native antigenic VLPs can be produced using protease-independent methods opens the possibility for future enteroviral vaccines to take advantage of recent vaccine technological advances, such as adenovirus-vectored vaccines and mRNA vaccines, circumventing the potential problems of cytotoxicity associated with 3CD, allowing for the production of immunogenic enterovirus VLPs in vivo.

microbiology↗

Gene interaction perturbation network deciphers a high-resolution taxonomy in colorectal cancer

Molecular subtypes of colorectal cancer (CRC) are currently identified via the snapshot transcriptional profiles, largely ignoring the dynamic changes of gene expressions. Conversely, biological networks remain relatively stable irrespective of time and condition. Here, we introduce an individual-specific gene interaction perturbation network-based (GIN) approach and identify six GIN subtypes (GINS1-6) with distinguishing features: (i) GINS1 (proliferative, 24%[~]34%), elevated proliferative activity, high tumor purity, immune-desert, PIK3CA mutations, and immunotherapeutic resistance; (ii) GINS2 (stromal-rich, 14%[~]22%), abundant fibroblasts, immune-suppressed, stem-cell-like, SMAD4 mutations, unfavorable prognosis, high potential of recurrence and metastasis, immunotherapeutic resistance, and sensitive to fluorouracil-based chemotherapy; (iii) GINS3 (KRAS-inactivated, 13%[~]20%), high tumor purity, immune-desert, activation of EGFR and ephrin receptors, chromosomal instability (CIN), fewer KRAS mutations, SMOC1 methylation, immunotherapeutic resistance, and sensitive to cetuximab and bevacizumab; (iv) GINS4 (mixed, 10%[~]19%), moderate level of stromal and immune activities, transit-amplifying-like, and TMEM106A methylation; (v) GINS5 (immune-activated, 12%[~]24%), stronger immune activation, plentiful tumor mutation and neoantigen burden, microsatellite instability and high CpG island methylator phenotype, BRAF mutations, favorable prognosis, and sensitive to immunotherapy and PARP inhibitors; (vi) GINS6, (metabolic, 5%[~]8%), accumulated fatty acids, enterocyte-like, and BMP activity. Overall, the novel high-resolution taxonomy derived from an interactome perspective could facilitate more effective management of CRC patients.

genetics↗

Active bulging promotes biofilm formation in a bacterial swarm

Microbial communities such as biofilms are commonly found at interfaces. However, it is unclear how the physical environment of interfaces may contribute to the development and behavior of surface-associated microbial communities. Combining multi-mode imaging, single-cell tracking and numerical simulations, here we discovered that an interfacial process denoted as "active bulging" promotes biofilm formation. During this process, an initially two-dimensional layer of swarming bacteria spontaneously develops scattered liquid bulges; the bulges have a higher propensity to transit from motile to sessile biofilm state, presumably due to the enrichment of pre-existing immotile cells in the colony. We further demonstrate that the formation of liquid bulges can be controlled reversibly by manipulating the speed and local density of cells with light. Our findings reveal a unique physical mechanism of biofilm formation and provide a new strategy for biofilm patterning in engineered living materials as well as for directed self-assembly in active fluids.

biophysics↗

Isolation and Transfection of Rice Egg Cells and Zygotes for Cellular Localization

Due to the difficulty in accessing to gametes and zygotes in flowering plants, which are controlled in single cells deeply embedded in multiple tissues, little is known about how the initiation of plant embryogenesis may reflect or contrast from such systems in other eukaryotes. In this study we has developed an approach of isolation and transfection of rice egg cells and zygotes for cellular localization of rice cell cycle factors (KRP5, KRP4 and FB3), which opened a pathway to monitor protein expression in rice egg cells and zygotes at different developmental stages. The advantageous feature of isolated rice cells may serve as an ideal system for studying the molecular mechanism underlying the rice zygotic division to initiate seed formation.

cell biology↗