Biology subjects

Banerjee, S.

Publications and source records attributed to Banerjee, S..

At least 37 records · Page 2Linked to original sources

bioRxiv2026

Phenological Plasticity without Directional Change: Tropical Hornbills Track Temperature but Maintain Reproductive Stability

Climate change is altering breeding phenology in birds worldwide, yet tropical systems remain understudied despite harbouring the greatest avian diversity. We drew upon 26 years (1998-2024) of breeding phenology and reproductive success data on three sympatric Asian hornbill species (Great Hornbill Buceros bicornis, Wreathed Hornbill Rhyticeros undulatus, Oriental Pied Hornbill Anthracoceros albirostris) from a tropical forest in northeast India to examine whether trends in long-term breeding parameters reflect directional climate change or interannual variability. Over the study period, we found no significant directional trends in nest entry timing, occupancy, or breeding success over 26 years, despite modest regional warming. However, breeding parameters showed sensitivity to interannual temperature variation, with pre-breeding temperature (January-February) explaining 36-70% of variance in nest timing. Temperature sensitivity differed among species, with Wreathed Hornbill showing the strongest response (-15.9 days/{degrees}C), followed by Great Hornbill (-9.8 days/{degrees}C), and Oriental Pied Hornbill showing the weakest (-4.8 days/{degrees}C), consistent with predictions that larger, frugivorous species with extended breeding cycles would exhibit greater climatic sensitivity. The underlying mechanism appears related to a body size-phenology-thermal exposure interaction: Oriental Pied Hornbills nest later (mid-April) with shorter breeding cycles ([~]90 days), completing reproduction before peak monsoon heat (June), whereas both larger species nest earlier (mid-February) but endure thermal stress throughout extended breeding cycles ([~]130+ days) into August. Notably, annual occupancy and breeding success remained stable across years despite strong phenological responses to temperature, suggesting that phenological plasticity may help maintain reproductive performance under current climatic variation. These findings indicate that tropical cavity-nesting frugivores exhibit phenological plasticity coupled with demographic stability, though the mechanisms underlying this apparent buffering remain incompletely understood, and body size-dependent differences in thermal exposure suggest heterogeneous vulnerabilities to future warming scenarios.

ecology↗

bioRxiv2026

Breast cancer stem cells mediated CD8+ T cell exhaustion among different molecular subtypes of breast cancer regulated via NOTCH1/RBPJ/PD-L1 axis

BackgroundBreast cancer stem cells (BCSCs) contribute significantly to breast cancer (BC) mortality among women globally. It underpins tumor heterogeneity in BC by driving variations in stemness potential and altering immune microenvironment. However, how BCSCs, subpopulations of breast cancer cells from distinct molecular subtypes differentially modulate CD8 T-cell exhaustion and immune dysfunction remain unclear. MethodsWe conducted our study from patients with BC of four subtypes. MACS sorted (Lin-CD44+CD24-) BCSCs were prepared for mammosphere formation assay from mastectomies samples. Flow-cytometry was used to analyze breast cancer stem cells (BCSCs). Immunofluorescence, immunohistochemistry, Real Time and Reverse Transcriptase PCR array, Chromatin-immunoprecipitation assay, Transwell, ELISA, Western blotting, Cloning, Transfection, Knockdown, chromatin immunoprecipitation approaches were used to investigate the underlying mechanisms. ResultsHere, we report that BCSCs actively participate in tumor progression by modulating effector CD8 T-cells. Triple-negative breast cancer (TNBC), being the subtype with the most adverse outcomes, sustains the enrichment of stem cell regulating transcription factors like NANOG, OCT4 and SOX2 compared to HER2, Luminal B, and Luminal A subtypes. Tumor from TNBC patients exhibited an exhausted phenotype within CD8 T-cell infiltrates with PD1high TIM3high LAG3 high IFN{gamma}low signature. BCSCs induced increased proportion of exhausted CD8 T-cells, predominantly in the TNBC subtype. Cell-surface Notch1 expression was upregulated in BCSCs across all molecular BC subtypes, with the highest elevation observed in TNBC. Knockdown or inhibition of Notch1 downregulated stemness-associated genes and diminished CSC-mediated induction of CD8 T-cell exhaustion. Cumulatively, these findings suggest that assessment of high Notch1 and Nanog frequency within BCSCs can guide Notch1-targeted therapies and may formulate for new combinatorial treatment strategies to improve patient outcomes. Additionally, therapeutic targeting of BCSC-intrinsic NOTCH1-NANOG/NOTCH1-PD-L1 axis could represent an effective strategy to reduce stemness programs and alter BCSC-driven CD8 T-cell exhaustion, majorly in aggressive subtypes such as TNBC. ConclusionsBCSCs aggressiveness is perpetuated through Notch1-mediated axis. Targeting Notch1 would reduce stemness (majorly NANOG), survival, as well as prevent CD8 T-cell exhaustion (upregulating PD-1, TIM3, LAG3), thereby weakening tumor progression.

cancer biology↗

bioRxiv2026

Novel COX-2 Targeted Nanobodies for Molecular Endoscopic Imaging of Colorectal Adenomas

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality in men and women. Timely detection and diagnosis are key to management of CRC, which is under-diagnosed because colorectal aberrant crypt foci, hyperplastic polyps, and microadenomas are often missed with conventional colonoscopy. The enzyme cyclooxygenase-2 (COX-2) is overexpressed in early stages of colorectal carcinogenesis and plays an important regulatory role in the process, suggesting that it could be a valuable target for enhanced imaging of nascent disease. Thus, we have generated an alpaca-derived library of 73 COX-2-specific nanobody clones. Here, we describe one such nanobody, F9-K45Q-K77Q-ROX, in which two native lysine residues have been mutated followed by conjugation to a fluorophore at the N-terminus with retention of COX-2-selective binding. The site of fluorophore conjugation and COX-2 binding affinity of F9-K45Q-K77Q-ROX were determined by proteomic and microscale thermophoretic analyses, respectively. In cell culture studies using 1483 human head and neck squamous cell carcinoma cells, F9-K45Q-K77Q-ROX accumulated inside cells and bound to intracellular COX-2, as visualized by fluorescence microscopy. In vivo pharmacokinetic, and toxicological analyses revealed that F9-K45Q-K77Q-ROX is detectable in circulation with a plasma half-life of 17.9 min and there is no short-term toxicity associated with single injections of 10 mg/kg, 20 mg/kg, or 40 mg/kg doses at 24 h post-administration. Noninvasive in vivo fluorescence endoscopic imaging validated tumor-specific accumulation of F9-K45Q-K77Q-ROX in azoxymethane/dextran sodium sulfate-induced colorectal adenomas in mice. This work demonstrates the first COX-2-targeted nanobodies including a fluorescent derivative that offers significant promise for targeted endoscopic imaging of COX-2-expressing neoplasms. Significance StatementCurrent colorectal cancer screening procedures, such as white-light colonoscopy, chromoendoscopy, and narrow-band imaging aim to detect solid colon tumors and precursor lesions. However, these methods tend to detect only raised solid tumors and mature cancers, whereas precursor lesions, such as aberrant crypt foci, hyperplastic polyps, and small adenomas are frequently missed. To address the need for better visualization of early lesions, we developed a library of alpaca-derived nanobodies targeted to cyclooxygenase-2 (COX-2), an enzyme that is overexpressed in colorectal adenomas. COX-2-targeted nanobodies bearing a fluorescent tag accumulate and are retained in colonic adenomas, facilitating their endoscopic visualization. This novel COX-2-targeted nanobody platform may also be valuable for early detection of other neoplastic diseases in which COX-2 overexpression occurs. (Word counts 119, limit 120)

bioengineering↗

bioRxiv2026

Divergent CRD-Dependent Mechanisms Govern RAS Isoform-Selective Recruitment of CRAF and ARAF

RAF kinases interpret signals from the three major RAS isoforms to initiate MAPK pathway activation, yet the molecular logic that governs isoform-specific RAS recruitment and the early events that relieve RAF autoinhibition are not yet fully understood. In particular, how the modular N-terminal regulatory architecture of CRAF and ARAF, anchored by the multifunctional cysteine-rich domain (CRD), discriminates among HRAS, KRAS, and NRAS has remained a central unresolved question. Here, we combine quantitative biophysical measurements with structural and dynamic analyses to define how RAS isoform identity and CRD engagement shape the earliest steps of RAF activation. These studies reveal unexpectedly divergent modes of RAS recognition between CRAF and ARAF and expose previously unappreciated functions of the CRD in modulating RAS affinity and intramolecular regulatory contacts. We further identify a direct link between RAS binding and destabilization of RAF autoinhibition, providing mechanistic insight into how RAS initiates the transition from an inactive monomer to an activation-competent assembly. Finally, we show that emerging KRAS inhibitors variably perturb KRAS-CRAF interactions, offering insight into how these therapeutics influence early RAS-RAF signaling events. Together, this work uncovers distinct biophysical principles that govern RAS-RAF selectivity and reveals a regulatory role for the CRD that reframes our understanding of RAF activation and its dysregulation in RAS-driven cancers. SignificanceProteins in the RAS-RAF signaling pathway control cell growth and are frequently mutated in cancer. Despite their importance, how different RAS proteins selectively recruit RAF kinases has remained incompletely understood. This study reveals that the cysteine-rich regulatory region of RAF plays a central role in distinguishing RAS isoforms and controlling RAF activation. These insights clarify early steps in MAPK signaling and may guide the development of improved therapies targeting RAS-driven cancers.

biochemistry↗

bioRxiv2026

C-Terminal Domain of Mycobacterium tuberculosis Glutamate Decarboxylase determines the bacterial stress-adaptive metabolic state that steers macrophage polarisation supporting intracellular persistence

Mycobacterium tuberculosis (Mtb) adapts metabolically to survive hostile conditions within alveolar macrophages, but whether specific enzyme-driven metabolic states of Mtb link stress adaptation to host immunomodulation remains unclear. Using LC-MRM/MS metabolite profiling and metabolic modeling, we previously identified elevated {gamma}-aminobutyric acid (GABA) production via the GABA shunt during adaptation to oxidative and acidic stress. Here, we show that stress-responsive enzymatic efficiency of glutamate decarboxylase (GadB) in producing GABA, not only mitigates acidic and oxidative stress but also drives macrophage polarisation towards the M2 phenotype, extending its role beyond bioenergetics into host-pathogen cross-talk. We identify the C-terminal domain (CTD) of mycobacterial GadB as a key regulator. Enzyme kinetics and fluorescence spectroscopy revealed that CTD deletion abolishes pH-dependent regulation of catalytic efficiency (kcat/Km) and substrate affinity (Ka). Under oxidative stress, the CTD enhances catalytic efficiency without altering substrate affinity, suggesting condition-specific roles. Accordingly, in vitro, Mtb::MtbGadB with higher GABA and [~]40% lower ROS outgrew Mtb::MtbGadB{Delta}Ct under acidic and oxidative conditions. These biochemical differences influenced host immunity, wherein infection with high-GABA-producing Mtb::MtbGadB strain induced M2 polarisation, with decreased CD86, reduced RNS, limited endosomal maturation, as indicated by Rab5/Rab7 ratio and Lysotracker-based confocal microscopy, and decreased TNF-, IL-12p70, and IFN-{gamma} release compared to low-GABA-producing Mtb::MtbGadB{Delta}Ct. Consequently, Mtb::MtbGadB{Delta}Ct showed higher clearance. We conclude that by enabling pH-dependent activity of GadB, the CTD orchestrates proton consumption, ROS reduction, and GABA-mediated immunomodulation. Distinct structural features of CTDs in human versus Mtb GADs highlight the CTD as a selective drug target for pathogen-specific, host-compatible therapies. ImportanceThis work establishes a direct mechanistic link between metabolic state of Mycobacterium tuberculosis (Mtb) actively shaping host immune responses, deciding infection outcome. The study identifies the C-terminal domain (CTD) of MtbGadB in steering enzymatic efficiency, regulating intrabacterial GABA production and ROS quenching, determining the stress-responsive metabolic state of the bacteria. Infection with metabolically distinct strains had differential impacts on host immunity, wherein infection with high-GABA-producing Mtb::MtbGadB induced M2-polarisation, reduced RNS, limited endosomal maturation, and reduced proinflammatory cytokine release, compared to low-GABA-producing Mtb::MtbGadB{Delta}Ct. Consequently, Mtb::MtbGadB{Delta}Ct could be cleared, but Mtb::MtbGadB persisted, deciding the fate of the infection. Structural differences between CTDs of human and Mtb GADs, make it a therapeutically-exploitable determinant for developing pathogen-specific drugs that remain compatible with the host.

microbiology↗

bioRxiv2026

Lysosomal Alkalinization Selects for Metabolically Plastic, Motile Cancer Cells under Nutrient Stress.

Cancer cells exposed to nutrient deprivation activate adaptive programs to survive metabolic stress, often acquiring enhanced plasticity and motility. We have previously reported that colon cancer cell lines that survived nutrient depletion underwent partial epithelial-mesenchymal transition (pEMT), which was further exacerbated when these cells also underwent lysosomal alkalinization. Here, we have attempted to dissect the molecular mechanisms that drive the motility and shape change from cobblestone to elongated in subpopulations of cells. Using RNA-seq-based bioinformatic analyses integrated with pathway scoring, protein-protein interaction networks, probabilistic modeling and confirmatory experimental data, we have identified the coordinated activation of sublethal apoptotic signaling, fatty acid oxidation, mitochondrial ROS generation, and Ca{superscript 2}-dependent lysosomal exocytosis in the nutrient-depleted cells. Among these phenotypes, the cells undergoing starvation and lysosomal alkalinization exclusively mediated lysosomal exocytosis and cell motility. Probabilistic modeling further revealed non-linear relationships between metabolic stress signals and cell fate transitions, highlighting heterogeneous lysosomal functions as a key determinant of the altered phenotype of cells under nutrient depletion. Overall, our study has identified that aberrant lysosomal functioning in cells under nutrient depletion can specifically select for a subpopulation of cells that are highly viable, metabolically plastic and capable of motility.

cell biology↗

bioRxiv2026

Wnt stimulation and inhibition in the development and phenotype of patient-derived gallbladder organoids

Gallbladder cancer (GBC) is a highly lethal malignancy with limited experimental models to study disease biology or evaluate therapeutic responses. Although canonical Wnt activation is commonly used for patient-derived organoid (PDO) development and expansion, gallbladder PDOs has also been generated under Wnt-inhibitory conditions. No comparative assessment has determined how Wnt pathway modulation influences gallbladder PDO development, phenotype or drug response. This study systematically compared the impact of canonical Wnt activation (WNTAct medium containing CHIR99021) versus inhibition (WNTInh medium containing DKK1) on the establishment, propagation, molecular features and therapeutic responses of PDOs generated from malignant or non-malignant gallbladder tissues derived from the same patient. Both media supported successful PDO generation with comparable efficiency, preserving biliary epithelial functions and marker expression. Transcriptomic profiling confirmed selective enrichment of canonical Wnt target genes in PDOs generated in WNTAct cultures. WNTAct conditions enabled markedly superior long-term propagation, whereas WNTInh cultures more consistently retained the dysplastic features in malignant samples. Gemcitabine response assays demonstrated significantly greater drug sensitivity in PDOs grown in WNTAct medium, a phenotype reversible upon media switching but requiring extended adaptation, indicating a dynamic and context-dependent influence of Wnt signaling on chemotherapeutic vulnerability. Collectively, the findings reveal a trade-off between long-term propagation and histological fidelity in gallbladder PDOs and show that Wnt signaling modulates gemcitabine sensitivity in a reversible manner. This comparative framework provides practical guidance for selecting culture conditions for gallbladder PDO based disease modelling and precision oncology applications.

cell biology↗

bioRxiv2026

Environmental Control of Antimicrobial-to-Amyloidogenic Switching in Uperin 3.5 by Surfactant Assembly Dynamics

Antimicrobial peptides (AMPs) that also form functional amyloids exhibit remarkable environmental sensitivity, yet the physicochemical rules governing their structural switching remain unresolved. Here, we investigate how surfactant charge and assembly dynamics regulate the antimicrobial-amyloidogenic transition of Uperin 3.5, a 17-residue amphibian AMP with pronounced conformational plasticity. Using an integrated approach combining all-atom molecular dynamics simulations with circular dichroism and thioflavin T fluorescence assays, we systematically probe the effects of surfactant identity, concentration relative to the critical micelle concentration (CMC), peptide stoichiometry and ionic strength. We show that -helical stabilisation and antimicrobial-like behaviour scale directly with surfactant charge: anionic Sodium dodecyl sulphate (SDS) induces the highest helicity in monomeric Uperin 3.5 ({approx}80-90%), followed by zwitterionic dodecyl-phosphocholine (DPC) ({approx}35-45%), while cationic Cetyltrimethylammonium bromide (CTAB) fails to stabilise secondary structure. This charge-ordered trend is mirrored in oligomer remodelling, with SDS driving the most rapid dissociation of {beta}-sheet tetramers, DPC inducing slower partial disassembly and CTAB exhibiting minimal effect. Above the CMC, micellar environments stabilise amphipathic -helical states and efficiently dissolve amyloid assemblies. In striking contrast, under below-CMC conditions, limited SDS availability combined with peptide crowding promotes cooperative aggregation, where surfactant monomers act as dynamic scaffolds that nucleate N-terminal {beta}-sheet interactions--an effect strongly accelerated by physiological salt. Large-scale simulations reveal mixed /{beta} aggregates whose formation is governed by electrostatic screening and surfactant-mediated co-assembly. Together, these findings establish surfactant charge and assembly state as quantitative, environment-dependent regulators of functional amyloidogenesis in antimicrobial peptides. More broadly, they suggest that controlled modulation of membrane-mimetic environments can be exploited to bias peptides toward antimicrobial or amyloidogenic states, offering conceptual avenues for therapeutic strategies targeting peptide misfolding and neurodegenerative disorders.

biochemistry↗

bioRxiv2026

Meiotic cohesin paralogs govern cell survival by exhibiting flexibility in partner choice

Erroneous loading of the ring-shaped cohesin complex, especially at centromeres, cause chromosomal segregation defects in both mitosis and meiosis. Mitotic cohesin subunits of this complex, either get replaced or co-exist with their meiotic paralogs during meiosis and also in certain cancers. However, it is unclear whether meiotic paralogs can partner mitotic subunits to form hybrid complexes in somatic cells and if there are any functional consequences on cancer progression. Here, we provide a conceptual framework for the principles of cohesin complex assembly involving non-canonical subunits in proliferating Schizosaccharomyces pombe. We show that chromosome loading, segregation fidelity and cellular proliferation are critically affected by the composition of the available cohesin complexes. We find stark differences in the ability of the meiotic kleisin subunit Rec8 to support robust centromere loading, irrespective of its partner, when compared to the canonical mitotic paralog Rad21. Such variations in cellular growth can be explained by different dwell times of these cohesin complexes on the chromosomes as determined by single-molecule tracking and altered chromatin enrichment. We also discover a unique feature of Rec8, in stabilizing chromatin-bound hypomorphic cohesin mutants that aid in cell survival under restrictive conditions. Overall, we highlight the flexibility of meiotic cohesins in restoring function, albeit at a fitness cost, in the presence of inactivating cohesin mutations. Such imbalances could be exploited by cancers to aid cell survival, but at the expense of increased aneuploidy and genomic instability.

molecular biology↗

bioRxiv2026

FTO-Dependent m6A RNA Dysregulation Underlies Memory Deficits Induced by Early-Life Stress

Cognitive functions in adults are mainly attributed to experience-dependent plasticity. Nonetheless, the developmental encoding of memory deficits is still inadequately addressed. Here, we demonstrate that early-life stress (ELS) reprograms the hippocampal epitranscriptome by enhancing N6-methyladenosine (m6A) deposits during early development leading to memory deficit in adulthood. We observed a shift toward hypermethylation of transcripts including coding and non-coding RNAs (lncRNAs) following maternal separation. We also observed that these transcripts encoding proteins necessary for translational regulation, ribosome biogenesis and mitochondrial function. This epitranscriptomic change is driven by ELS-induced downregulation of the m6A demethylase FTO (Fat mass and obesity-associated protein). We observe that the overexpression of FTO in young adult mice selectively rescues memory deficits without ameliorating elevated anxiety. Further, the knockdown of FTO in primary hippocampal neuron, mimicking ELS - induced reduction of its expression, leads to reduced translation as detected by puromycin labelling. Taken together, our study demonstrated previously uncharacterized mechanism of ELS-induced epitranscriptomic change linked with memory deficit via the regulation of protein synthesis.

neuroscience↗

bioRxiv2026

A Complete Genome for the Common Marmoset

The common marmoset is a New World monkey (NWM) commonly used as a model organism to investigate questions in primate evolution and human disease, including Alzheimers and other neurodegenerative diseases, as well as neuropsychiatric disorders. Here we present the first telomere-to-telomere (T2T) reference genome for the common marmoset, adding over 88 Mb of sequence and resolving challenging genomic regions. An additional near-T2T assembly from a second unrelated individual yields a total of four high-quality haplotypes for analysis. The improved contiguity and accuracy of these assemblies enable unprecedented insights into complex and rapidly evolving genomic regions such as centromeres, sex chromosomes, ribosomal DNA (rDNA) structure, and the major histocompatibility complex (MHC). We fully resolved all marmoset centromeres, uncovering dimeric alpha satellites with chromosomal specificity and stratified inactive layers documenting ancestral centromere turnover. We assembled six acrocentric autosomes with gene-poor, satellite-rich short arms and provide evidence that most of them can harbor rDNA and all of them share large pseudo-homologous regions (PHRs). The Y chromosome, but not the X chromosome, carries active rDNA and PHRs, and the rDNA copy number is sexually dimorphic. Chromosomes that share PHRs also share closely related centromeric satellite DNA, supporting a model of ongoing recombinational exchange between heterologous chromosomes facilitated by rDNA. We discovered multiple novel, marmoset-specific MHC genes that are predicted to protect against pathogens encountered in its environment. Leveraging this complete reference, we further identified over 500 transcribed genes with transcript models or expansions specific to the marmoset lineage. Together with additional long-read marmoset assemblies, these genomes were used to construct a marmoset pangenome, providing a robust reference framework for short-read mapping across diverse individuals. This resource will improve the utility of the common marmoset as a biomedical model organism and fill key gaps in our understanding of primate evolution.

genomics↗

bioRxiv2026

SARS-CoV-2 PLpro Drives Epithelial Barrier Disruption Across Drosophila and Mammalian Epithelia

Severe SARS-CoV-2 infection manifests as a systemic disorder characterized by catastrophic loss of epithelial homeostasis and dysregulated host inflammation. However, which specific viral factors initiate this tissue damage in intact, living organisms remains unresolved. Using a comprehensive in vivo screen of all 25 SARS-CoV-2 nonstructural proteins (NSPs) and accessory factors (ORFs) in the Drosophila wing imaginal epithelium, here we have identified NSP5 (Main protease, Mpro) and NSP3--specifically its papain-like protease (PLpro) domain--as individual triggers of tissue injury. Focusing further on PLpro, we demonstrate that its expression initiates a self-amplifying host cell stress signaling circuit driven by metabolic overdrive, oxidative stress, and hyperactivation of Akt, JNK, and JAK-STAT signaling. However, this pathogenic loop is fragile; genetic suppression of any of the hyperactivated signaling nodes collapses this network, thereby restoring epithelial homeostasis. This organ-intrinsic, PLpro-induced epithelial vulnerability is also seen in the adult midgut and larval respiratory system. Notably, in the larval respiratory system, PLpro drives compartment-specific pathologies: it induces fibrosis-like remodeling in terminally differentiated squamous tracheal tubes, while catastrophically depleting the progenitor-competent tracheoblasts and air sac precursors (ASP). Both these defects are reversed by the genetic knockdown of PLpro-induced JAK-STAT signaling. Finally, we show that PLpro expression in mammalian MDCK epithelia similarly triggers junctional remodeling and inflammatory stress signaling. Our findings position PLpro as a central driver of COVID-19 pathogenesis through a self-amplifying epithelial stress circuit that compromises epithelial homeostasis across organs and species.

cell biology↗

bioRxiv2026

RasG12V Oncogene-Induced Epithelial Senescence and Its Relay Promotes Host Metabolic Syndrome in Drosophila

Precancerous oncogenic activation in a target organ often induces senescence, a tumor-suppressive response known as oncogene-induced senescence (OIS). Clinical observations indicate a strong association of metabolic syndrome (MetS) with the precancerous and early-stage cancers. Notably, cells displaying OIS are characterized by a senescence-associated secretory phenotype (SASP), in which they secrete factors, including inflammatory cytokines. Thus, SASP from cells displaying OIS may trigger host MetS, which likely underpins its association with cancers, such as colorectal cancer (CRC). Here, we tested this hypothesis and show that, in Drosophila, the activated RasG12V oncogene, which is frequently implicated in human CRC, induces OIS in imaginal disc epithelium and systemically triggers host larval MetS via the conserved cytokine Upd1/IL6. Thus, the larval host with RasG12V-induced epithelial OIS displays MetS, characterized by obesity, increased lipid and glycogen accumulation in the fat body, and altered insulin signaling, marked by transition from hyperinsulinemia to insulin resistance--all at a precancerous stage. Further, we also noted hyperphagia and increased expression of insulin-like peptides (dILP2/3/5) in the brain of larvae displaying RasG12V-induced OIS. Notably, RasG12V-induced OIS is systemically relayed, leading to activation of a senescence-like program in the distant fat body. Genetic suppression of upd1 or pharmacological intervention with the senomorphic agent, Metformin, attenuated fat body senescence and mitigated MetS-associated phenotypes. Our findings thus identify a causal relationship between OIS and host MetS, suggesting its utility as an early biomarker for detecting cancers such as CRC and its potential as a prophylactic target.

cancer biology↗

bioRxiv2026

AI-Driven Generation of Cortisol-Binding Peptides for Non-Invasive Stress Detection

Cortisol is a primary biomarker of stress, released in sweat at concentrations that directly correlate with physiological stress levels. Detecting cortisol non-invasively offers significant potential for real-time stress monitoring and healthcare applications. Biosensors capable of binding cortisol can thus enable the development of novel diagnostic platforms for personalised health management. In our earlier work, a 38-mer peptide fragment derived from the protein 2V95 was identified as a functional binder to cortisol. In the present study, we applied generative artificial intelligence (AI) approaches to expand the sequence space and identify superior candidate peptides with improved binding affinity. By integrating sequence-based and structure-based AI models, we generated and screened a peptide library of nearly 10,000 sequences against cortisol, leading to the identification of high-affinity candidates for further evaluation.

bioengineering↗

bioRxiv2026

Climate-linked divergence in tree flowering and fruiting in an Eastern Himalayan tropical forest

PremiseLong-term phenological patterns are increasingly being examined from the perspective of climate change and its potential effects. Climatic effects on plant phenology could involve the direct responses to changes in temperature, precipitation and solar irradiance, or could be mediated by these variables through exogenous teleconnections such as the El Nino Southern Oscillation (ENSO). The effects of climatic fluctuations on inter-annual variation in tropical phenology remain understudied. MethodsWe examined long-term patterns of tree flowering and fruiting intensity in a tropical forest site in the Eastern Himalayas between 2011 and 2024. Species-specific patterns were examined for 36 species. Long-term patterns were quantified using Generalized Additive Models, and splines were visualized to infer trends. Through Generalized Linear Mixed Models, we determined if there was a lagged phenological response to ENSO and temperature, precipitation and solar irradiance, and whether ENSO effects were being mediated through the latter group of variables or plant traits. ResultsBetween 2011 and 2019, trends in flowering and fruiting were significant for 17 and 23 species respectively. Flowering increased for 7 species, while fruiting declined for 8 species. Flowering peaked during El Nino, but this association did not appear to be mediated through climate variables, whereas fruiting showed a three-month positive lagged response to solar irradiance, independent of ENSO. The peak season of reproduction was the only trait determining species-specific responses to climate variables. ConclusionOur study highlights nonlinearity in long-term patterns of reproductive phenology, and the importance of solar irradiance in determining inter-annual fruit production.

ecology↗

bioRxiv2026

Mitochondrial structural and functional defects in the Drosophila melanogaster model of PLA2G6 Associated Neurodegeneration (PLAN)

PLA2G6-associated neurodegeneration (PLAN) is a rare progressive disorder caused by mutations in PLA2G6, which encodes calcium-independent phospholipase A2, an enzyme required for phospholipid remodeling and membrane lipid homeostasis through the Lands cycle. Although mitochondrial dysfunction has been implicated in PLAN, how PLA2G6 loss affects mitochondrial structure and function across tissues, age, and sex remains unclear. Here, we used homozygous null iPLA2-VIA mutant Drosophila melanogaster, a model of PLAN, to examine mitochondrial ultrastructure, abundance, function, DNA content, and mitochondrial maintenance gene expression. Transmission electron microscopy revealed severe mitochondrial abnormalities in the brain, thorax, and ovary from 7-day-old and 3-week-old mutant flies, including disrupted cristae, abnormal morphology, and compromised membrane structure. Mutants also showed reduced mitochondrial number, which became more widespread with age. MitoTracker imaging further showed reduced mitochondrial staining and abnormal clumped mitochondrial distribution in mutant brains. Consistent with mitochondrial depletion, mitochondrial DNA content was reduced in mutants, with decreased ATPase6 but unchanged nuclear ATPSynC levels. Functionally, mutants exhibited reduced ATP production across multiple tissues and at the whole-body level, while ROS levels changed in a tissue-, age-, and sex-dependent manner. Transcript analysis showed reduced mTOR and PGC-1 expression, altered expression of fusion and fission genes including Opa1, Drp1, and Fis1, age- and sex-dependent changes in Pink1, reduced Trap1 expression in aged mutants, and unchanged Sirtuin 6 expression. Together, these findings show that iPLA2-VIA is required for mitochondrial maintenance and bioenergetic integrity in vivo.

cell biology↗

bioRxiv2026

Validation of a Single Nepl15 Transcript in Oregon-R Drosophila melanogaster with Minor Coding Sequence Variation Relative to FlyBase

The Neprilysin-like 15 (Nepl15) transcript in Drosophila melanogaster displays sex and organ specific phenotypes and only has one known transcript in the fly database (FlyBase.org). Given that the Nepl15 gene is differentially expressed in a tissue-specific and sex-specific manner, we sought to identify if there were additional Nepl15 transcripts available in Oregon-R strain flies which had not been reported in the fly database by performing sequencing-based approaches. We have identified presence of different codons in the transcript different than what had been reported in FlyBase. Further experimentation is needed to determine the full effect of these changes on fly physiology.

genomics↗

bioRxiv2026

Drosophila melanogaster Nepl15 regulates lifespan, motor function, aging, heart rate, and cellular health in a sex-specific manner

Aging and obesity are characterized by comorbidities like declines in fertility, lifespan, gut barrier integrity, cardiac function, and motor activity, and an increase in oxidative stress due to altered nutrient and energy homeostasis. A study on Drosophila Neprilysin-like 15 (Nepl15) demonstrated that loss of Nepl15 gene significantly reduced glycogen and glycerolipid reserves in adult males and increased glycogen storage in adult females despite similar food consumption as controls. Therefore, we investigated the sex- and age-specific consequences of Nepl15 loss on cellular and physiological parameters associated with aging and obesity. We observed that egg production, rate of pupariation, and rate of adult fly eclosion were slightly better in the mutant flies. Interestingly, mutant females, but not males, exhibited significantly extended lifespan. Both sexes demonstrated improved locomotor performance, exercise endurance, gut barrier integrity, and preserved heart rate during progressive aging. At the cellular level, female mutants displayed reduced oxidative stress, elevated Sod2 expression, and increased ATP levels, all indicative of enhanced cellular health. Mutant males exhibited an increased mitochondrial membrane potential, indicating an enhanced capacity for rapid ATP production in response to enforced activity. Consistently, the energy-sensing kinase AMPK expression was reduced in the mutants. The lifespan extension of mutant females was supported by downregulation of mTOR and upregulation of Sirt6 expression. However, in mutant males, both mTOR and Sirt6 were downregulated, potentially contributing to improved physiological health without changing their lifespan. Collectively, our findings establish Nepl15 knockout mutation promotes anti-aging and anti-obesity health benefits, with stronger effects in female flies.

cell biology↗