Cell Structure and Function
● Japan Society for Cell Biology
Preprints posted in the last 30 days, ranked by how well they match Cell Structure and Function's content profile, based on 11 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.
Clifford, G.; Taylor, S. J. P.; Ishii, M.; Cisneros-Soberanis, F.; Akiyoshi, B.
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Acquiring nutrients is a fundamental biological process of all organisms, playing crucial roles in ecological sustainability. Diplonemids are highly abundant heterotrophic unicellular flagellates that are widespread in the worlds ocean. They have a highly complex microtubule-based feeding apparatus (cytostome-cytopharynx complex) located adjacent to the deep flagellar pocket from which two flagella emerge from parallel basal bodies. The apical papilla is a tongue-shaped structure unique to diplonemids that connects the cytopharynx and the flagellar pocket, the latter of which is formed by reinforcing microtubules (MTR) and two flagellar roots called intermediate and dorsal roots. Here we report identification of 17 proteins that localize at the feeding apparatus or flagellar apparatus in Diplonema papillatum. Using ultrastructure expansion microscopy, we show that Mad2 and its interaction partner MBP65 localize at the MTR, intermediate root, and dorsal root. Homologs of proteins that associate with the flagellar apparatus in Trypanosoma brucei (PFR2, KMP11, BILBO1) localize at the feeding apparatus in D. papillatum. We also identify proteins that localize at the apical papilla, MTR, parallel microtubule loop, or cytopharynx. By discovering components of the feeding apparatus for the first time in diplonemids, this work forms the foundation to understand molecular mechanisms of the feeding apparatus in these highly abundant marine plankton.
Chang, N.; Ugulini, S.; Dhanvantari, S.
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The secretion of glucagon from the pancreatic alpha () cell within the islets of Langerhans is physiologically regulated by nutrients (glucose, amino acids, fatty acids), neurotransmitters, and paracrine hormones. Insulin and somatostatin form an intra-islet paracrine network to control glucagon secretion through direct inhibitory effects on cell secretory granule exocytosis. In a potential new cellular pathway for the regulation of glucagon secretion, we have previously identified the neuronal trafficking protein Stathmin-2 (Stmn2) as a negative regulator of glucagon trafficking and secretion by directing glucagon to degradative lysosomes. In this study, we examined if insulin and somatostatin direct glucagon to lysosomes in a Stmn2-dependent manner as part of their paracrine mechanisms. Using the TC1-6 glucagon-secreting cell line and confocal microscopy of both fixed and live cells, we show that insulin and somatostatin direct glucagon, glucagon+LAMP1+ vesicles, and LAMP1-RFP to the intracellular region, away from sites of exocytosis. As visualized in live cells, insulin treatment resulted in the rapid retrograde transport of lysosomes from the cell periphery, and this effect was lost under siRNA-mediated silencing of Stmn2. Somatostatin appeared to enhance the intracellular retention of lysosomes, also in a Stmn2-dependent manner. We determined a possible mechanism for Stmn2 in the regulation of lysosome transport in TC1-6 cells through the Arf-like small GTPase Arl8, indicating that Stmn2 may function in lysosomal positioning along microtubules. We propose that Stmn2-mediated lysosomal transport may be a potential new pathway, in addition to inhibition of secretory granule exocytosis, through which insulin and somatostatin regulate glucagon secretion.
Jathar, S. R.; Srivastava, J.; Dongardive, V.; Tripathi, V.
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Long noncoding RNAs (LncRNAs) have emerged as a class of important regulatory ncRNAs and are known to fine-tune numerous cellular processes including proliferation, differentiation and development; however, their role in quiescence still remains largely unexplored. A miRNA host gene lncRNA, MIR503HG, has been reported to play important role in cancer development. Here, we demonstrate the role of MIR503HG lncRNA in regulating cellular quiescence. MIR503HG displays elevated levels in human diploid fibroblasts induced to undergo quiescence. Depletion of MIR503HG in HDFs affects the entry of cells into quiescence but has no effect on cell cycle progression, suggesting its role in quiescence attainment and/or maintenance. Additionally, MIR503HG depletion led to a drastic decrease in the levels of miR508 target, PTEN with a concomitant increase in pAkt levels, indicating its role in negative regulation of miR508. Further, we demonstrate that the lncRNA MIR503HG regulates PTEN levels by acting as a ceRNA for miR508 to maintain cellular quiescence. Our studies illustrate that MIR503HG can function synergistically with miR503 to maintain cells under quiescence and both the miRNA-HG and the miRNA encoded by its gene locus synergistically control the same biological process in different ways by regulating different downstream genes.
Kariyazono, R.; Tanabe, H.; Osanai, T.
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Chromosome spatial organization plays critical roles in transcriptional regulation and DNA protection. In cyanobacteria--oxygenic photosynthetic bacteria that experience dramatic fluctuations in light intensity--chromosome reorganization may facilitate rapid transcriptional reprogramming and protect DNA from photodamage. However, direct observation of chromosome organization in these polyploid organisms has remained technically challenging, leaving light-dependent chromosomal responses unexplored. Here we show that local chromosome organization in Synechocystis sp. PCC 6803 is reorganized in response to high-light stress. We established fluorescence in situ hybridization (FISH) methods for this model cyanobacterium carrying multi-copy genomes, together with a computational pipeline for optimal same-genome-copy probe pairing. Under standard conditions, spatial distance between paired signals increased with genomic distance (slope {beta} = 0.972 nm/kbp, R{superscript 2} = 0.12), demonstrating that linear genome organization is reflected in three-dimensional chromosome structure at the 25-124 kbp scale. This genomic-spatial distance relationship substantially weakened under high-light conditions ({beta} = 0.450 nm/kbp, R{superscript 2} = 0.02), indicating that local chromosome organization is disrupted by elevated light intensity. Same-color nearest-neighbor distances further revealed that the spatial distribution of genome copies differed between conditions, independently supporting condition-dependent chromosome reorganization. Hi-C analysis corroborated these findings, revealing reduced short-range interactions within the 10-100 kbp genomic range under high-light conditions. Our integrative single-cell and population-level approach provides a framework for investigating how environmental signals modulate higher-order chromosome structure in polyploid bacteria.
Domingues-Silva, B.; Azzalin, C. M.
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Mammalian telomeric DNA comprises long tracts of tandem TTAGGG repeats. The same repeats are also found at internal chromosomal regions called interstitial telomeric sequences (ITSs). Telomeres are transcribed into UUAGGG-containing transcripts, named TERRA, which serve multiple functions in maintaining telomere integrity. Complementary RNAs containing C-rich telomeric repeats, named ARIA, have also been identified in few yeast mutants and mammalian cells with dysfunctional telomeres. The molecular features and functions of ARIA remain understudied, mainly due to its low abundance and the lack of suitable cellular systems. Here, we show that Chinese hamster ovary (CHO) cells produce abundant TERRA and ARIA transcripts, predominantly originating from ITSs. Both RNAs are polyadenylated, exhibit relatively short half-lives and form large cellular foci. We also show that ARIA depletion leads to exposure of single-stranded (ss) DNA at ITSs and that ssDNA exposure increases when ITS DNA is damaged. SsDNA formation does not require the DNA damage signaling kinases ATM and ATR, nor the exonucleases DNA2 and EXO1; however, ATM prevents excessive ssDNA accumulation when ARIA function is inhibited. These findings establish CHO cells as a powerful model to dissect telomeric RNA functions and reveal ARIA as a key regulator of telomeric repeat DNA integrity.
Korkiamäki, R. O.; Thapa, C.; Green, H. J.; Ylänne, J.
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Mechanosensing involves proteins detecting mechanical changes in the cytoskeleton or at cell adhesion sites. These interactions initiate signaling cascades that produce biochemical effects such as post-translational modifications or cytoskeletal rearrangements. Filamin is a ubiquitous mechanosensing protein that binds actin filaments and senses pulling forces within the cytoskeleton. Drosophila Filamin (Cheerio) is structurally similar to mammalian Filamin, with roles in egg chamber development, embryo cellularization, and integrity of muscle attachment sites and Z discs in Drosophila indirect flight muscles (IFMs). Here we report a potential novel binding partner of Drosophila Filamins: the death-associated protein kinase Drak that functions as a myosin light chain kinase. We found that Drak biochemically bound to an open mutant of Filamin that resembles the mechanically activated form partially bound to wild type Filamin and did not bind to closed mutant of Filamin. The interaction site was mapped to the intrinsically unfolded C-terminal region of Drak. To study the functional role of Drak-Filamin interaction, we studied two developmental events where Drak has been earlier shown to be expressed and where Filamin also functions: early embryonic cellularization and indirect flight muscle development at pupal stages. We found partial colocalization between Drak-GFP and Filamin-mCherry during the initiation of cellularization furrow, and at the time of myotube attachment site maturation in tendon cells. However, functionally we could not show direct correlation between Filamin and Drak. Our studies reveal interesting new expression patterns of Drak during Drosophila development and provide detailed information about Filamin localization during IFM development.
Yakimovich, A.; Krause, M.; Vago, N.; Drexler, I.; Mercer, J.
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Autophagy is a catabolic process used for the degradation of organelles and proteins. Macroautophagy involves the formation of autophagosomes and subsequent fusion with lysosomes to mediate cargo degradation. It also functions as a cellular defence mechanism, known as xenophagy, during infection. Previous studies show that different viruses manipulate the autophagy pathway of the host cell to assure successful replication and/or virion assembly. Vaccinia virus (VACV), the prototypic poxvirus, replicates exclusively in the cytoplasm of host cells. It is known that VACV infection causes LC3 lipidation and prevents autophagosome formation, yet the double membrane vesicles formed during autophagy do not serve as the source of the mature VACV membrane. To date the viral protein(s) causing increased LC3 lipidation have not been identified. Here we developed an image-based screening approach based on LC3 granularity to identify candidate VACV genes affecting its lipidation. We identify several candidate viral membrane proteins as effectors of LC3 lipidation, suggesting that the interplay between VACV and autophagy is more directed than previously thought.
Yu, D.; Zhang, Q.; Cao, L.; Gu, S.; Zhang, Y.; Liu, C.; Yin, K.; Wang, J.; Pan, B.; Liu, Y.; Zhou, G.; Lan, D.; Huang, Y.; Basang, W.
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Primarily inhabiting the harsh, high-altitude environment of the Qiangtang National Nature Reserve exceeding 5,000 meters above the sea (m.a.s.l.), the golden wild yak is critically endangered, with fewer than 300 individuals remaining in the world, a situation exacerbated by the significant challenges of conducting research and conservation of their genetic resources. Somatic cell nuclear transfer (SCNT) can be an effective method for their preservation, but facing several obstacles in this context, including the hypoxic stress at high altitude that impairs embryonic development due to in vitro manipulation, and constraints of long-distance embryo transport. In the present study, the ear tissue was collected from a childhood male golden wild yak at Xizang Geye Wildlife Rescue Station (4800 m.a.s.l.) and send to Institute of Animal Science at Beijing to derive fibroblast cells. Using fibroblast cells of the golden wild yak as nuclear donors, and bovine oocytes from a local slaughterhouse at Beijing as recipients, the interspecific SCNT (iSCNT) embryos were generated and in vitro developed to blastocysts. To maintain the embryonic viability after long-distance transportation from Beijing to Xizang, iSCNT blastocysts were subjected to cryopreservation by vitrification method. Thawing of vitrified iSCNT blastocysts were completed at Xizang Dangxiong Yak Breeding Innovation Base (4200 m.a.s.l.), and transferred into the uterine horn of domestic yaks. 257 days after blastocyst transfer, a cloned golden wild yak was successfully harvested on January 10, 2026. This work demonstrates, for the first time, that interspecies somatic cell nuclear transfer can successfully produce a cloned offspring under extreme conditions, spanning 4800 m.a.s.l. donor origin, long-distance vitrified embryo transportation, and high-altitude blastocyst transfer at 4200 m.a.s.l., establishing a viable strategy for conserving critically endangered high-altitude species.
ding, y.; lu, t.; Li, y.
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Liquid-liquid phase separation (LLPS) of biomacromolecules is a key mechanism driving the formation of membraneless organelles (MLOs) within cells, playing a crucial role in fundamental biological processes such as cell proliferation and stress response. Accurately understanding and predicting the phase separation propensity of proteins is essential for unraveling the assembly mechanisms of MLOs and their functions under both physiological and pathological conditions. Traditional research methods primarily rely on biochemical experiments, which are limited by low throughput, high cost, and difficulty in systematically exploring sequence-phase transition relationships. This study proposes and implements a novel three-stage, iterative paradigm based on artificial intelligence (AI) to propel phase separation research towards systematization, predictability, and mechanistic understanding. O_LIBenchmark Model Construction: A preliminary predictive model was established based on a Multilayer Perceptron (MLP) neural network, and the driving effect of phenylalanine/tyrosine (F/Y) residue-mediated {pi}-{pi} interactions on LLPS was validated. C_LIO_LIModel Robustness Enhancement: The model was optimized through adversarial training strategies, which effectively identified and eliminated misclassifications of "highly disordered non-phase-separating" trap sequences. This significantly improved the models generalization capability and reliability when handling complex, real-world sequences. C_LIO_LIPhysical Mechanism Integration and Functional Expansion: Incorporating the Uniform Manifold Approximation and Projection (UMAP) manifold learning method and constraints from non-equilibrium thermodynamics, a "fingerprint space" capable of characterizing the thermodynamic behavior of phase separation was constructed. This space enables cluster analysis of different MLO types, and the model can output a thermodynamic stability score for protein phase separation. Based on this score, we identified 10 high-confidence candidate proteins with the potential to form novel MLOs. The paradigm established in this study upgrades phase separation prediction from the traditional "binary classification" approach to a novel research framework characterized by "physical mechanism analysis + novel MLO discovery." It provides the phase separation field with a computational tool that combines high accuracy, strong robustness, and good physical interpretability. C_LI
Merle, L.; Martin-Jaular, L.; Thery, C.; Joliot, A.
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Extracellular vesicles are key intercellular messengers that modulate the function of target cells by carrying effectors, either at their surface or in their lumen. In the latter case, their action depends on the ability to deliver their content into the cytosol of target cells. How efficiently EVs deliver their content upon interaction with their target cell is thus a central question for understanding the functional impact of this mode of action. To address this question, signal-driven bimolecular interactions between two partners located respectively in the EV lumen and the target cell cytosol have become a widely used strategy to detect the cytosolic delivery EV content. However, the detection of cytosolic delivery with these assays was often tributary to the artificial enhancement of the fusion between EV and cell membranes, through for instance VSV-G fusogenic protein expression. Here we provide a robust and quantitative LUCiferase-based complementation assay (HiBiT/LgBiT), to quantify the Internalization and cytosolic Delivery of EV content: LUCID-EV. By optimizing the signal-to-noise ratio of the assay, the method for loading HiBiT fragment into EVs (fusion to a lipid-binding domain rather than to tetraspanins), and the intracellular position of LgBiT (associated to membranes), we could quantify cytosolic delivery from various non-VSV-G-expressing EVs into target immune dendritic cells. Importantly, this delivery did not involve the acidic late endosomes environment required for VSV-G-dependent EV cytosolic delivery. The limited efficacy of the process highlights the need for highly sensitive assays like the one described here. Further development of the LUCID-EV assay could help identifying EV/target cells pairs with enhanced cytosolic delivery properties and characterize the cellular route for delivery.
Ortmann de Percin Northumberland, C.; Licheva, M.; Dabrowski, R.; Gomez-Sanchez, R.; Berkamp, S.; Schonnenbeck, P.; Graef, M.; Kraft, C.; Sachse, C.
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The autophagy core machinery mediates the enclosure of cytosolic cargo destined for degradation in the lysosome. The Atg9-Atg2-Atg18 complex coordinates phagophore expansion via directed lipid transfer until closure of the phagophore rim. Using an Atg2 variant (Atg2-PM4) as a model of decelerated autophagosome biogenesis, we visualized the morphological states prior to autophagosome closure by cryogenic correlative light and electron microscopy in S. cerevisiae. Using in situ cryo-electron tomography, we find an enlarged rim morphology of an expanding phagophore in Atg2-PM4 cells in comparison with Atg2 wildtype condition. Analysis of segmented rim membrane features as well as surrounding and attached vesicles suggest that the enlarged rims are a result of cytosolic vesicles fusing with the growing phagophore. High-resolution imaging in this study shows that, apart from the initial nucleation phase, vesicle fusion can also contribute to phagophore expansion during later stages of autophagosome biogenesis.
Sato, Y.; Hamazaki, K.
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Individual phenotypes often depend on the genotypes of other individuals within a group. These phenomena are termed indirect genetic effects (IGEs) and have been distinguished from direct genetic effects (DGEs) using quantitative genetic models. Recent studies have utilized high-resolution polymorphism data to enable genomic prediction (GP) and genome-wide association study (GWAS) of IGEs, but unified methods remain limited. Here we integrate polygenic and oligogenic IGEs using a multi-kernel mixed model incorporating two random effects with a single covariance parameter. Underlying this implementation, the Ising model of ferromagnetics enabled us to simplify locus-wise and background IGEs for GWAS and GP, respectively. Our simulations demonstrated that, while the previous and present models exhibited similar performance, the present model can infer a trade-off between DGEs and IGEs. By applying this method to three species of woody plants, we found evidence for intergenotypic competition in aspen and apple trees, but limited evidence in climbing grapevines. Based on GWAS, we also detected significant variants associated with the competitive IGEs on the apple trunk growth. Our study offers a flexible implementation for GWAS/GP of IGEs, thereby providing an effective tool to dissect the genetic architecture of group performance.
Tetard, M.; Lin, T.; Peterson, N. A.; Gullberg, R. C.; Le Guen, Y.; Doench, J. G.; Egan, E. S.
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Terminal erythroid differentiation involves dramatic cellular remodeling that culminates in the expulsion of the nucleus, a process known as enucleation. While enucleation is conserved across mammals and is crucial for the generation of fully functional erythrocytes, the mechanisms governing this process have remained largely unknown, in part because the absence of genetic material in mature, enucleated red blood cells hinders genetic experimentation. Here, we performed a pooled, forward-genetic CRISPR-Cas9 screen in enucleated red blood cells derived from primary human hematopoietic stem cells to identify genes required for enucleation. We found that Chloride Intracellular Channel 3 (CLIC3) and Vesicle-associated membrane protein 8 (VAMP8) are both necessary for terminal erythroid differentiation, yet likely act through different mechanisms. Knockdown of CLIC3 led to a delay in erythroblast differentiation, culminating in impaired enucleation. We found that the knockdown cells had increased p53 and p21 and exhibited cell cycle alterations, suggesting CLIC3 plays a crucial role in coordinating cell cycle progression during erythropoiesis. In comparison, VAMP8-depleted cells initially appear to undergo accelerated differentiation but then display a specific defect in enucleation. Transcriptional analysis of the VAMP8-knockdown cells suggested dysregulation of pathways for vesicle trafficking and actin binding, and imaging of late-stage erythroblasts revealed impaired nuclear polarization and disorganized actin. This work provides a new approach for functional genomics in enucleated cells and reveals novel factors important for terminal erythroid differentiation and enucleation. Key pointsO_LIA CROPseq-based CRISPR-Cas9 screen enables functional genomics in enucleated primary human red blood cells. C_LIO_LIChloride Intracellular Channel 3 (CLIC3) and Vesicle Associated Membrane Protein 8 (VAMP8) were identified as critical for terminal erythroid differentiation and enucleation, likely acting through two distinct mechanisms. C_LI
Tahmaz, I.; Borghi, F. F.; Milan, J. L.; Kunemann, P.; Petithory, T.; Bendimerad, M.; Luchnikov, V.; Anselme, K.; Pieuchot, L.
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Cells dynamically integrate biochemical and mechanical signals arising from their surrounding microenvironment to regulate morphology and behavior. Mechanical cues like matrix stiffness, surface topography, and other physical perturbations modify biophysical signals. Surface topography, particularly curvature regime acts as any important mediator of mechanotransduction by coordinating cytoskeletal organization, focal adhesion dynamics, and nuclear architecture. Curvature response has been demonstrated at broader length scales and influences nucleus shape change, chromatin organization, and gene regulation, positioning the nucleus as an active mechanosensitive hub. Bone tissue consists of a curvature-rich microenvironment defined by a trabecular architecture at tissue scale and by resorption cavities such as Howships lacunae at cellular scale. While these geometries are essential for homeostasis, their role in pathological context remains poorly understood. Osteosarcoma develops within this mechanically complex multiscale architecture, but how bone-inspired curvature regulates nuclear behavior and signaling in osteosarcoma cells remains unclear. Here, we engineered three-dimensional (3D) concave hemispherical substrates that recapitulate nucleus-scale bone micro-curvature and assessed their effects on human SaOS-2 osteosarcoma cells. In comparison with flat surfaces, concave confinement resulted in pronounced nuclear rounding and softening, accompanied by Lamin A/C reorganization and increased heterochromatin compaction marked by H3K9me3. Curvature-driven nuclear remodeling selectively modulated Hippo pathway main effectors YAP/TAZ without activating NF-{kappa}B mediated canonical inflammatory responses. Furthermore, cells maintained overall viability without elevated pathological DNA damage or apoptotic signaling, suggesting an adaptive, damage-tolerant nuclear response. Overall, these findings indicate nucleus-scale curvature as a critical regulator within the bone microenvironment that governs nuclear modelling and mechanosensitive signaling in osteosarcoma cells. Incorporating physiologically relevant geometry into in vitro models establishes new insight into cancer microenvironment crosstalk and highlights nuclear interior and outer architecture as a key regulator of tumor cell behavior.
Vijay, A.; Bhagavatheeswaran, S.; Balakrishnan, A.
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Angiogenesis, the process by which new blood vessels form from existing vasculature, is fundamental to tissue repair and regeneration but also underlies pathological conditions such as cancer progression. Targeting angiogenesis has thus become a promising approach for developing novel cancer therapeutics. While various phytochemicals have demonstrated anti-angiogenic effects, the role of 2-5(H)-Furanone, a naturally occurring lactone found in various plants and marine sources with diverse biological activities, remains insufficiently explored. In this study, we systematically evaluate the anti-angiogenic potential of 2-5(H)-Furanone using Human Umbilical Vein Endothelial Cells (HUVECs) as an in vitro model and zebrafish embryos as an in vivo model. Experimental findings demonstrated that treatment of HUVECs with increasing concentrations of 2-5(H)-Furanone led to significant, dose-dependent reductions in proliferation, invasion, migration, and tube formation. Analyses of gene expression revealed marked downregulation of key pro-angiogenic mediators, VEGF, and HIF-1. Complementing these in vitro results, in vivo studies in zebrafish embryos showed robust, dose-dependent inhibition of intersegmental vessel (ISV) formation, accompanied by suppression of critical angiogenesis-related genes. Molecular docking further supported these observations by indicating stable binding of 2-5(H)-Furanone to major angiogenic targets, including VEGFR2, MMP2, HIF-1, and PIK3CA. Collectively, our data demonstrate that 2-5(H)-Furanone potently inhibits angiogenesis, as evidenced in both HUVEC and zebrafish models, through functional and molecular mechanisms. These findings support the further development of 2-5(H)-Furanone as a promising anti-angiogenic therapy candidate.
Yang, H.; Zhao, L.; Zhou, X.; Li, X.; Huang, X.; Tian, Y.
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Text abstractsLipid homeostasis is essential for organismal physiology, and its disruption contributes to metabolic disorders. Using an unbiased genetic modifier screen in Drosophila, we identified GAR1, a core component of the box H/ACA small nucleolar ribonucleoprotein complex, as a pivotal regulator of systemic lipid storage. We show that the H/ACA snoRNP complex is essential for maintaining lipid droplet morphology in adipose tissue and preventing ectopic fat accumulation. Moreover, null mutants of Gar1 or Dkc1 exhibit severe developmental defects, including reduced body size and larval lethality. RNA-seq analysis revealed that Gar1 dysfunction triggered widespread alternative splicing defects, specifically targeting key transcripts within the insulin signaling cascade, including chico, Pi3K92E, sgg, and Lip4. Furthermore, knockdown of Gar1 impaired insulin signaling, as evidenced by the reduced membrane localization of the tGPH fluorescence. Genetic epistasis further positions GAR1 upstream of the lin-28/foxo axis, as knocking down lin-28 or foxo fully rescues the lipometabolic defects in GAR1-deficient animals. These findings reveal a previously unrecognized link between the snoRNP machinery and metabolic process, establishing the box H/ACA complex as an important coordinator that integrates RNA processing with insulin-mediated nutrient sensing to ensure developmental and lipid homeostasis. Article summaryLipid metabolism is tightly controlled by multiple factors. To find new regulators, the authors performed a genetic screen and identified a small nucleolar protein GAR1 participate in fat storage and larval development. They demonstrated a critical role of box H/ACA snoRNP complex in modulating alternative splicing and balancing insulin cascade. Blocking two insulin-related genes reversed the lipid defects caused by Gar1 loss. These findings revealed the box H/ACA complex integrates RNA processing with insulin-mediated nutrient sensing to ensure developmental and lipid homeostasis, offering a perspective for understanding the metabolic regulation network.
Cierco, C.; Santos, F.; Nobrega-Pereira, S.; da Cruz e Silva, O.; Trigo, D.
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Mitochondrial membrane potential ({Delta}{Psi}m) is central to ATP production, ion homeostasis, and cell survival, reflecting the functional state of the inner mitochondrial membrane and oxidative phosphorylation. Accurate assessment of {Delta}{Psi}m is therefore essential for understanding mitochondrial physiology and dysfunction in health, ageing, and disease. Lipophilic cationic fluorescent dyes, such as TMRM and TMRE, are widely used to monitor {Delta}{Psi}m in live cells, enabling high-temporal-resolution imaging of both steady-state membrane potential and dynamic fluctuations. Beyond stable bioenergetic measurements, live-cell imaging reveals transient, reversible depolarisation events, known as mitochondrial "flickers." These events, observed across multiple cell types and imaging platforms, are often associated with brief openings of the mitochondrial permeability transition pore (mPTP) and may represent regulated mitochondrial excitability, rather than irreversible damage. While excessive or synchronised depolarisations may signal mitochondrial injury, transient flickers are increasingly viewed as potential signalling mechanisms within the mitochondrial network. This work discusses methodological considerations for {Delta}{Psi}m imaging, the biological significance of mitochondrial flickers, and the importance of distinguishing physiological events from probe- and light-induced artefacts, highlighting the emerging concept of mitochondria as dynamic and communicative bioenergetic networks.
von Heyl, T.; Pauli, T. M.; Rieblinger, B.; Schleibinger, S. T.; Liang, W.; Schmauser, A.; Arullmoli, M.; Derrer, P.; Eckstein, A.; Jagana, S.; Gatti Correa, C.; Flisikowski, K.; Flisikowska, T.; Schusser, B.
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Pigs and chickens are not only the most important livestock species for global food production but also serve as key model organisms in various research disciplines. The pig is widely used in translational research due to its anatomical and physiological similarity to humans, providing valuable insights into immunology, metabolism, and disease mechanisms. In contrast, the chicken has become an essential model for studies related to poultry health, animal welfare, and developmental biology. Its externally developing embryo offers exceptional accessibility for experimental manipulation. Recent advances in genome editing technologies, particularly CRISPR/Cas9, have further expanded the potential of these species for functional genomic studies, although the efficient delivery of such tools remains a major challenge. By using virus-like particles (VLPs), we have been able to overcome this limitation. Here, we evaluated VLPs as delivery vehicles for genome engineering tools in pigs and chickens, two key livestock species at the human-animal interface. VLP-mediated delivery enabled efficient Cre recombination and high CRISPR/Cas9 editing rates in porcine cells, organoids, and oocytes, particularly when multiplexed. In chickens, VLPs supported robust Cre recombination and Cas9-mediated editing in cell culture, tracheal organ cultures, and in ovo. Reporter VLPs and dCas9 VLPs further demonstrated the versatility of this platform across porcine and avian systems. Together, these findings establish VLPs as an efficient and time-saving strategy for gene editing in livestock, with relevance for animal health, agricultural productivity, and translational One Health research.
Couturier, F.; Cravero, C.; Lesur, I.; Confais, J.; Belmonte, E.; Piat, L.; Marande, W.; Rellstab, C.; Valbuena, M.; Saez-Laguna, E.; Duvaux, L.
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We present a genome assembly from a specimen of Quercus canariensis (Fagaceae; Fagales; Magnoliopsida). The assembly was generated using PacBio HiFi long reads with an approximate sequencing depth of 39X and scaffolded using a reference-guided approach. The genome sequence has a total length of 816.0 megabases for haplotype 1 and 804.8 megabases for haplotype 2. The two haplotypes are each resolved into 12 chromosomal pseudomolecules, with only 3.48% and 1.36% of sequences remaining unplaced in haplotypes 1 and 2, respectively. Assembly completeness is supported by BUSCO scores of 98.3% and 98.2% complete genes for haplotypes 1 and 2, respectively. Structural annotation identified 51,882 and 46,482 protein-coding genes in haplotypes 1 and 2, respectively. This genome assembly provides the first chromosome-scale reference genome for Q. canariensis, laying the base for future genomic and evolutionary studies in this understudied species of the hybridizing white oak species complex. TaxonomyLineage cellular organisms; Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta; Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae; rosids; fabids; Fagales; Fagaceae; Quercus EBI:txid568684 Quercus canariensis Willd. 1809 (Willdenow)
Lu, Y.; Pan, M.; Jamwal, V.; Locop, J.; Ruparelia, A. A.; Currie, P. D.
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Quantitative histological analysis of skeletal muscle morphometry provides critical insights into muscle physiology but remains labor-intensive and technically demanding. While recent developments in machine-learning-based image segmentation techniques have facilitated large-scale tissue analysis, existing tools that automate muscle morphometry analysis are largely tailored to mammalian models, with limited applicability to teleosts. Moreover, there is a lack of effective tools for visualizing spatial organization and morphometric variability of teleost muscle fibers, a feature that is important for understanding hyperplastic muscle growth dynamics in teleosts. In this study, we show that cytoplasmic staining combined with deep learning-based cell segmentation offers a robust and accurate approach for automated muscle morphometry analysis in developing zebrafish. We also introduce a FIJI2 plugin, implemented in Jython, that streamlines both morphometric analysis and visualization. This tool accommodates shallow and deep learning-based segmentation techniques and incorporates novel quantification and visualization methods suited to teleost-specific muscle features, including mosaic hyperplasia dynamics. The plugin features an intuitive graphical user interface and is designed for flexibility, with minimal constraints regarding species, image quality, or staining protocol. Its modular architecture allows it to be used as a baseline for automated muscle morphometry analysis, while permitting integration with other tools and workflows.