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Saxena, A.

Publications and source records attributed to Saxena, A..

At least 19 recordsLinked to original sources

Astrocyte molecular rhythm disruption in nucleus accumbens promotes increased binge-like drinking in mice

Alcohol misuse is a leading cause of preventable death worldwide. Chronic alcohol is associated with disrupted circadian rhythms, yet molecular mechanisms linking circadian rhythm dysregulation and alcohol consumption are poorly understood. Current FDA-approved treatments for alcohol use disorder (AUD) do not target molecular rhythms or sleep-wake cycles. Mammalian circadian rhythms are regulated by transcription-translation feedback loops that regulate expression of 'clock genes' (e.g., Arntl encoding for BMAL1). Both human and rodent studies demonstrate associations between clock gene variants and changes in reward-seeking behavior. Evidence suggests astrocytes, non-neuronal brain cells with cell-autonomous rhythms, may regulate both circadian rhythms and reward. In the nucleus accumbens (NAc), a region responsible for modulating alcohol- and reward-related behavior, over 43% of the astrocyte transcriptome is expressed rhythmically. However, no studies to date have investigated roles of NAc astrocyte rhythmicity in regulating alcohol drinking. We used AAV8-Gfap-Cre to functionally ablate molecular rhythms in NAc astrocytes of BMAL1 floxed mice. Two-bottle choice (2BC), drinking-in-the-light (DIL), and drinking-in-the-dark (DID) assessed alcohol drinking. Behavioral assays included locomotor response to novelty, sucrose preference, and social interaction. Disrupting molecular clock function in NAc astrocytes increased binge-like drinking during both DIL and DID paradigms (d = 1.44), but not with any other drinking paradigm or behavior. This study carves out a unique role for astrocytes in controlling the temporal organization of reward circuitry and susceptibility to binge-drinking. Future studies will investigate clock-controlled astrocyte mechanisms, such as glutamate uptake and ATP release, that may underlie binge-like drinking behavior.

neuroscience↗

Interlayer Communication Integrates Genetic and Mechanical Signals for Robust Leaf Morphogenesis

Leaf development requires coordinated growth across distinct tissue layers, integrating genetic regulation with mechanical coupling to achieve proper organ shaping. However, the mechanisms coordinating differentiation and growth across layers to ensure coherent leaf morphogenesis remain poorly understood. Therefore, we investigated the role of TCP4 as a potential central regulator of interlayer communication coupling genetic and mechanical signals during Arabidopsis leaf development. Three-dimensional analyses revealed pronounced asymmetry in the expression of TCP4 and its negative regulator, MIR319C, across developing primordia, establishing spatially patterned differentiation cues. Tissue-specific perturbations demonstrated that TCP4 activity in either epidermis or subepidermis modulates cell proliferation and expansion across layers through both protein mobility and mobility-independent signalling mechanisms. Strong epidermal TCP4 induction arrested leaf development by prematurely suppressing proliferation and preventing symmetry breaking, thereby locking primordia in cylindrical states. Live imaging revealed fundamental reprogramming of growth anisotropy, with TCP4 driving cortical microtubule alignment, increasing cell wall stiffness, and establishing layer-specific pectin patterns. Together, these findings establish TCP4 as an integrator of genetic and mechanical signals across leaf tissue layers, coupling transcriptional programmes to cytoskeletal organisation, cell wall remodelling, and cross-layer mechanical feedback.

plant biology↗

Multi-Stage Graph Attention Networks for Interpretable Alzheimer's Disease Classification from Genome-Wide Association Data

BackgroundGenome-wide association studies have identified numerous variants associated with neuropsychiatric disorders. Although some significant loci can carry substantial risk, as in Alzheimers Disease, the remaining genetic variance is distributed across many small-effect loci. Polygenic risk scores (PRS) aggregate this risk but do not capture epistatic interactions, and offer limited biological interpretability and predictive accuracy. Computing gene level risk scores and integrating known or statistically validated gene-gene associations has the potential to increase interpretability and/or accuracy. Graph Neural Networks (GNNs) can leverage graph structured genetic data that models potential epistatic interactions to achieve these goals. MethodsWe developed a three-stage Graph Attention Network (GAT) classifier using individual-level GWAS data from 7,358 participants across seven Alzheimers Disease Center cohorts. Nodes were defined as genes, with risk scores from AD and 11 genetically correlated phenotypes serving as features. We evaluated two graph construction strategies: gene co-expression networks derived from hippocampal transcriptomic data and curated pathway-based graphs. Additionally, a bilinear context module was incorporated to capture global gene-gene interactions beyond the graph topology. In Stage 1, a GNN encoder was trained on the graphs; Stage 2 injected PRS for non-coding SNPs after the encoder to better capture genetic risk via transfer learning, and Stage 3 applied adversarial training with gradient reversal for ancestry debiasing. GNN predictions were ensembled with whole-genome PRS using elastic net regression. ResultsThe best-performing GNN model -- a GAT with bilinear context operating on the pathway graph -- achieved an AUROC of 0.78 (95% CI: 0.75-0.80). Ensemble models combining Stage 2 or 3 GNN logits with whole-genome PRS achieved an AUROC of 0.82 (0.79-0.84), outperforming PRS alone (0.80). GxI attribution and additional explainability analyses revealed stage-specific biological signals, some of which re-capitulated known gene-phenotype associations and others which may reflect potential new areas of inquiry. ConclusionA multi-stage GAT framework captures complementary, non-additive genetic signal that, when ensembled with PRS, improves the accuracy of AD classification. Post-hoc explainability analyses yield biologically interpretable gene networks, supporting the utility of graph-based deep learning for dissecting complex genetic architectures.

neuroscience↗

Membrane localisation and checkpoint blockade enhance xenoantigen delivery to redirect pre-existing immunity against tumours

Cancer immunotherapies often rely on the recognition of tumour antigens, which strongly limits their efficacy upon heterogeneous antigen expression or downregulation. A strategy to overcome this limitation is to redirect pre-existing antiviral immunity against tumours through the delivery of xenoantigens. While many studies have addressed this by repurposing licensed vaccines, we here investigated the underlying mechanisms of immune redirection via the delivery of non-adjuvanted xenoantigen proteins, thereby avoiding confounding adjuvant- or pathogen-specific effects. Using B16F10 melanoma cells engineered to express the model antigen OVA, we found that tumour rejection in pre-immunised mice depends on the subcellular localisation of the xenoantigen, with membrane-bound antigens eliciting stronger rejection than dose-matched soluble cytoplasmic antigens. Enhanced rejection of membrane-bound OVA expressing tumours was associated with stronger CD4+ T cell responses. In addition, pre-immunisation also increased recruitment of inflammatory monocytes and macrophages at the tumour site. To translate this concept therapeutically, we developed a membrane-targeting OVA fusion protein which, upon intratumoural delivery, redirected pre-existing immunity and made tumours responsive to anti-PD-1 therapy. Importantly, these findings were further validated using the clinically relevant varicella zoster virus (VZV) glycoprotein E (gE) antigen and the licensed varicella vaccine Varivax. Our approach provides a mechanistic and translational perspective for treating poorly immunogenic tumours, leveraging widespread pathogen-specific immune memory in combination with anti-PD1 therapy in cancer patients.

cancer biology↗

Propionate metabolism dysregulation promotes drug-tolerant persister cell survival in non-small cell lung cancer

Recent studies show that genetic sequencing can not fully explain drug resistance in non-small cell lung cancer (NSCLC), suggesting undiscovered non-genetic mechanisms that can enable cancer cell survival. Propionate metabolism is the pathway by which odd-chain fatty acids, branched chain amino acids, and cholesterol are metabolized. We have previously shown that methylmalonic acid (MMA), a byproduct of propionate metabolism that accumulates when the pathway is disrupted, can activate epithelial-to-mesenchymal transition (EMT) in cell lines. But the clinical significance of propionate metabolism in cancer patients is not known. Here we show, for the first time, that propionate metabolism is dysregulated in patients with non-small cell lung cancer. MMA is elevated in lung tumors and in the serum of patients with metastatic NSCLC. Metabolism of cobalamin associated B (MMAB), a key regulatory gene of propionate metabolism, is downregulated in NSCLC and drug-tolerant persister cells, leading to MMA accumulation and EMT activation. We show that restoring expression of MMAB in NSCLC enhances targeted therapy and suppresses TGFB signaling. These findings reveal propionate metabolism dysregulation as a non-genetic mechanism of drug resistance and highlight propionate metabolism as a potential therapeutic target.

cancer biology↗

Paired plus-minus sequencing is an ultra-high throughput and accurate method for dual strand sequencing of DNA molecules

Distinguishing real biological variation in the form of single-nucleotide variants (SNVs) from errors is a major challenge for genome sequencing technologies. This is particularly true in settings where SNVs are at low frequency such as cancer detection through liquid biopsy, or human somatic mosaicism. State-of-the-art molecular denoising approaches for DNA sequencing rely on duplex sequencing, where both strands of a single DNA molecule are sequenced to discern true variants from errors arising from single stranded DNA damage. However, such duplex approaches typically require massive over-sequencing to overcome low capture rates of duplex molecules. To address these challenges, we introduce paired plus-minus sequencing (ppmSeq) technology, in which both DNA strands are partitioned and clonally amplified on sequencing beads through emulsion PCR. In this reaction, both strands of a double-stranded DNA molecule contribute to a single sequencing read, allowing for a duplex yield that scales linearly with sequencing coverage across a wide range of inputs (1.8-98 ng). We benchmarked ppmSeq against current duplex sequencing technologies, demonstrating superior duplex recovery with ppmSeq, with a rate of 44%{+/-}5.5% (compared to [~]5-11% for leading duplex technologies). Using both genomic as well as cell-free DNA, we established error rates for ppmSeq, which had residual SNV detection error rates as low as 7.98x10-8 for gDNA (using an end-repair protocol with dideoxy nucleotides) and 3.5x10-7{+/-}7.5x10-8 for cell-free DNA. To test the capabilities of ppmSeq for error-corrected whole-genome sequencing (WGS) for clinical application, we assessed circulating tumor DNA (ctDNA) detection for disease monitoring in cancer patients. We demonstrated that ppmSeq enables powerful tumor-informed ctDNA detection at concentrations of 10-4 across most cancers, parts per million sensitivity in cancers with high mutation burden, and further increased sensitivity with higher sequencing depth. We then leveraged genome-wide trinucleotide mutation patterns characteristic of urothelial (APOBEC3-related and platinum exposure-related signatures) and lung (tobacco-exposure-related signatures) cancers to perform tumor-naive ctDNA detection, showing that ppmSeq can identify a disease-specific signal in plasma cell-free DNA without a matched tumor, and that this signal correlates with imaging-based disease metrics. Altogether, ppmSeq provides an error-corrected, cost-efficient and scalable approach for high-fidelity WGS that can be harnessed for challenging clinical applications and emerging frontiers in human somatic genetics where high accuracy is required for mutation identification.

genomics↗

A Spatial and Temporal Transcriptomic Atlas of Mouse Intestinal Regeneration

Background & AimsThe intestinal epithelium exhibits a remarkable capacity for regeneration following injury. However, the spatial and temporal dynamics of the injury-repair cycle remain incompletely understood. MethodsWe employ spatial transcriptomics to create an atlas of the damage and repair response to ionizing radiation in the mouse intestine. We map molecular events driving epithelial recovery over a six-day period and 23 biological samples, spanning the early apoptotic response to tissue remodeling and repair. ResultsThe datasets capture mRNA of 19,042 genes in [~]26 million bins at 2{micro}m resolution. Analysis revealed transcriptional patterns and niche signals that would remain undetected in bulk or single-cell approaches, including a non-random activation of interferon-target genes. Temporal shifts in cytokine and growth factor gene expression, particularly in the crypt and lower villus regions, corroborate published studies and reveal new predictions of the mechanisms governing intestinal healing. Global transcriptional upregulation was observed in the regenerating epithelium, suggesting hypertranscription is a hallmark of intestinal repair. Furthermore, we observe altered cellular differentiation trajectories and villus patterning at the early stages of regeneration. ConclusionsTogether, our work provides a detailed spatiotemporal map of intestinal regeneration at subcellular resolution and nearly whole-genome scale. These data lay the groundwork for future discoveries and therapeutic strategies to enhance epithelial repair in inflammatory bowel diseases and other gastrointestinal pathologies or in response to side-effects of cancer therapies.

molecular biology↗

What's next for Indian Ornithology? 101 key research questions

India has a rich history of ornithology, and bird research in this field has expanded considerably in recent decades, spurred by a growing number of birdwatchers and ornithologists. Despite this progress, critical gaps remain. This paper highlights key areas where further research is needed and identifies pressing questions that will shape Indian ornithology in the coming years. Drawing from diverse inputs, we present a curated list of 101 research questions spanning across the various disciplines in ornithology - Natural History, Physiology and Disease Ecology, Behaviour, Population and Community Ecology, Habitat Ecology, Macroecology and Biogeography, Population Genetics and Evolution, Applied/Economic Ornithology and Conservation. The list was compiled through a multi-stage process, starting with a public open call for questions, followed by review and curation by a smaller panel of subject specialists. Each question was independently scored by a panel of experts based on three criteria: generality, novelty, and relevance. To account for variation in scoring styles, scores were normalised using Z-scores. The top 101 research questions were then selected based on these standardised scores. Each question is accompanied by an annotation that describes the significance of the question, and highlights opportunities to address it. While our list of research questions highlights significant research priorities, it is not intended to be exhaustive. Rather, it reflects the perspectives of those involved in its curation, who deemed these questions particularly relevant and impactful towards advancing Indian ornithology. We expect these questions to spark new project ideas among students, researchers, and citizen scientists, while guiding funders, managers, and policymakers toward priority research areas.

ecology↗

microRNA-21 promotes dysregulated lipid metabolism and hepatocellular carcinoma

Backgrounds and AimsThe prevalence of hepatocellular carcinoma (HCC) is rising in parallel with increasing obesity and metabolic dysfunction-associated steatohepatitis (MASH). MicroRNAs are key post-transcriptional regulators of gene expression and are attractive targets for HCC therapy. Here we sought to identify and characterize dysregulated microRNAs in MASH-driven HCC (MASH-HCC). Approach and ResultsWe profiled microRNA expression in liver tissue from patients with MASH and/or MASH-HCC and in zebrafish HCC driven by activated {beta}-catenin (ABC), one of the most commonly mutated oncogenes in MASH-HCC. We found significant overlap between dysregulated human and zebrafish miRNAs, including miR-21, which was increasingly upregulated from normal liver to MASH to MASH-HCC. We generated transgenic zebrafish that overexpress or sponge (downregulate) miR-21. We found that miR-21 overexpression caused larval liver overgrowth and increased HCC while miR-21 sponge suppressed {beta}-catenin-driven larval liver overgrowth. By performing histologic and lipidomic analysis, we found that overexpression of miR-21, like ABC, suppressed lipid accumulation in response to a high cholesterol diet and increased accumulation of acylcarnitines. ConclusionsHere we characterize microRNA dysregulation in MASH and MASH-HCC in patients, identify miR-21 as increasingly dysregulated from MASH to MASH-HCC, and delineate the impacts of miR-21 overexpression on lipid metabolism and hepatocarcinogenesis in zebrafish {beta}-catenin-driven HCC. This study shows that miR-21, which is similarly dysregulated in human and zebrafish HCC, promotes lipid metabolic changes that may help drive hepatocarcinogenesis.

cancer biology↗

Pan-Cancer PDOs Preserve Tumor Heterogeneity and Uncover Therapeutic Vulnerabilities

We developed a tumor-matched, pan-cancer patient-derived organoid (PDO) platform comprising 220 PDOs from 190 patients across 15 cancer types to advance functional precision oncology. Our comprehensively characterized PDOs showed 93% histopathology concordance, 80% median genomic concordance for driver mutations, and a 0.85 median gene expression correlation with parent tumors. Gene expression in PDOs remained stable across [≥] 10 passages, supporting reproducibility for long-term drug screening. Even PDOs with low genomic concordance retained oncogenic drivers, supporting their use as disease models. Clonality analysis revealed that 85% of PDOs preserved dominant tumor clones. Higher genomic concordance was associated with greater clonal similarity, while lower genomic concordance was associated with clonal divergence. Functional assays showed that 58% of PDOs from a subset of patients ineligible for FDA-approved PARP inhibitors responded to Talazoparib, with sensitivity linked to alterations in DNA damage repair. Combination screens revealed drugs that effectively overcame resistance, especially in TP53-mutant PDOs. In summary, our platform supports investigation of targeted therapies, identification of molecular features linked to drug sensitivity, and translational discovery, offering insights into personalized cancer treatment beyond current biomarker guidelines.

cancer biology↗

Genetic compensation in podocalyxin-like mutants during zebrafish liver development

Hepatic stellate cells (HSCs) are critical for normal liver development and regeneration. Podocalyxin-like (podxl) is highly expressed in zebrafish HSCs, but its role in liver development is not known. Here we report that podxl knockdown using CRISPR/Cas9 (CRISPants) significantly decreased HSC number in zebrafish larvae at different time points and in two independent HSC reporter lines, supporting a role for podxl in HSC development. We generated five podxl mutants, including two mutants lacking the predicted podxl promoter region, and found that none of the mutants recapitulated the knockdown phenotype. Podxl CRISPR/Cas9 injection in mutants lacking the podxl guide RNA cut site did not affect HSC number, supporting the hypothesis that the CRISPant phenotype was specific, requiring intact podxl. Podxl mRNA levels in three podxl mutants were similar to those of wildtype controls. RNA sequencing of podxl mutants and controls showed no significant change in transcript levels of genes with sequence similarity to podxl, but it revealed upregulation of a network of extracellular matrix genes in podxl mutants. These results support a role for podxl in zebrafish liver development and suggest that upregulation of a group of functionally related genes represents the main mechanism of compensation for podxl genomic loss.

developmental biology↗

VIVIDHA: Variant Prediction and Visualization Interface for Dynamic High-throughput Analysis

Large scale genome sequencing projects have produced huge datasets that pose challenges of high processing times especially for variant calling, a significant downstream analysis step. Efficient utilization of computational resources for accurate variant prediction in a timely manner is possible using Hadoop MapReduce framework. We have developed VIVIDHA (Variant Prediction and Visualization Interface for Dynamic High-throughput Analysis), a high throughput methodology for prediction of variants based on splitting the alignment file using overlapping regions using Hadoop MapReduce framework. The size of overlap region is user-defined. Three variant callers viz. GATK, VarScan2 and BCFTools have been included to predict variants using a consensus approach. Speed-up observed provides the rationale of better performance as number of compute cores and file size are increased. VIVIDHA is available in both GUI as well as command-line modes and can be downloaded from URL: https://github.com/bioinformatics-cdac/VividhaInstaller

bioinformatics↗

Epigenetic Control of TERRA by FTSJ3 is Critical for Telomerase-Driven Cancers

Telomerase reverse transcriptase (hTERT) overexpression, a hallmark of most cancers, drives tumorigenesis by enabling limitless replicative potential. Direct targeting of hTERT is challenging, necessitating alternative strategies. Through genome-wide synthetic dosage lethality (SDL) screening in cancer models, including patient-derived organoids, we identify FTSJ3, an RNA 2-O-methyltransferase, as a critical vulnerability in hTERT-overexpressing cells. FTSJ3 methylates telomeric repeat-containing RNA (TERRA), a modification essential for recruiting SUV39H1 to telomeric ends to mediate H3K9 trimethylation and establish stable heterochromatin. Loss of FTSJ3 disrupts this cascade, impairing H3K9 trimethylation, HP1-alpha recruitment, and telomeric heterochromatin maintenance. Notably, this reveals an unexpected dependency on TERRA methylation for telomeric heterochromatin stability in hTERT-driven cancers. Non-malignant cells, lacking telomerase activity and de novo telomere repeat synthesis, are unaffected by FTSJ3 suppression. Our findings establish the FTSJ3/TERRA/SUV39H1 axis as a critical mechanism supporting telomeric heterochromatin stability in hTERT-driven cancers. This telomere-directed epigenetic strategy provides a robust framework for translational therapeutic innovation.

cancer biology↗

Attenuated adenosine mediated immune-dampening increases natural killer cell activity in early age-related macular degeneration

Non-exudative age-related macular degeneration (AMD) involves retinal pigment epithelium (RPE) dysfunction and has been linked to altered intraocular immunity. Our investigation focuses on immune cell subsets and inflammation-associated factors in the eyes with early and intermediate AMD. We observed elevated levels of activated natural killer (NK) cells and interferon-{gamma}, concurrent with reduced myeloid-derived suppressor cells (MDSCs) and adenosine in AMD eyes. Aqueous humor from AMD patients had diminished ability to dampen NK cell activation, an effect rescued by adenosine supplementation. The Cryba1 cKO mouse model recapitulated these immune alterations, and single-cell RNA-sequencing identified NK cell-related genes and NK cell-RPE interactions. Co-culture of activated NK cells with RPE cells induced barrier dysfunction and Gasdermin-E driven pyroptosis providing a functional link relevant to AMD. These findings suggest a double-hit model where elevated immune activation and loss of immune dampening mechanisms drive AMD progression. Resetting the intraocular immune balance may be a promising therapeutic strategy for managing early and intermediate AMD. O_FIG O_LINKSMALLFIG WIDTH=198 HEIGHT=200 SRC="FIGDIR/small/634301v2_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1516bfaorg.highwire.dtl.DTLVardef@87f505org.highwire.dtl.DTLVardef@1e725caorg.highwire.dtl.DTLVardef@622717_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstractC_FLOATNO Illustra tion of pro posed mechanism underlying NK cell-RPE interaction in early AMD pathogenesis. Dysregulated NK cell communicate s with stressed RPE in early AMD immunopathology. Aberrant AMD aqueous humor and retina shows increased NK cells and NK effector molecules like IFN{gamma} with reduced MDSC and adenosine in human subjects, don or eye and animal model. Activated NK cells interaction with RPE causes dysfunction and pyroptotic cell death via Gasdermin-E pathway in AMD.. Created with BioRender.com C_FIG

immunology↗

Disruptive changes in tissue microenvironment prime oncogenic processes at different stages of carcinogenesis in lung

Carcinogenesis is characterized not only by the uncontrolled growth of malignant cells but also by the disruption of the normal balance of cellular processes and intercellular interactions in the microenvironment that overcome the constraints of tissue homeostasis and support malignant growth. We profiled benign pulmonary dysplasia, carcinoma in situ, and invasive lung carcinomas at single-cell resolution to identify composite changes in cellular processes, signaling, and interactions among tumor-immune-stromal cells in the microenvironment in progressively advanced disease stages. We developed OncoTerrain, a hyperparameter-tuned model that captured synergistic multimodal signatures of an increasingly perturbed microenvironment in malignant disease stages and identified composite microenvironmental changes that supported cancer hallmarks. Key cancer-related changes in transcriptional states, cellular processes, and intercellular interactions involving immune, fibroblast, and stromal cell types preceded tumor initiation and were often synergistic. The microenvironment of increasingly malignant tissues was characterized by immune avoidance, ECM remodeling, and altered cell mobility. There were changes in cell states in fibroblasts, macrophages, and their inter-cellular interactions with other cell types, whereas T-cell activation occurred late. The in-situ carcinomas showed variations in the composite microenvironmental states that corroborated their pathology, which was not apparent at the genome level. A subset of those harbored populations of tumor and non-tumor cells with aggressive characteristics in some but not all aspects of hallmarks of carcinogenesis in the lung. We suspect that the variation in the coordination of microenvironmental cues may influence why some but not all in-situ tumors progress to the advanced stages.

genomics↗

Highly Pathogenic Avian Influenza A (H5N1) clade 2.3.4.4b Virus detected in dairy cattle

The global emergence of highly pathogenic avian influenza (HPAI) A (H5N1) clade 2.3.4.4b viruses poses a significant global public health threat. Until March 2024, no outbreaks of this virus clade had occurred in domestic cattle. We genetically characterize HPAI viruses from dairy cattle showing an abrupt drop in milk production. They share nearly identical genome sequences, forming a new genotype B3.13 within the 2.3.4.4b clade. B3.13 viruses underwent two reassortment events since 2023 and exhibit critical mutations in HA, M1, and NS genes but lack critical mutations in PB2 and PB1 genes, which enhance virulence or adaptation to mammals. The PB2 E627K mutation in a human case underscores the potential for rapid evolution post-infection, highlighting the need for continued surveillance to monitor public health threats.

microbiology↗

Evaluation Of Suitability Analysis of Gangetic Water from Upper, Middle, And Lower Ganga Rivers

This study assesses the suitability of water from distinct segments of the Ganga River in India for drinking, irrigation, and industrial purposes, utilizing various indices. Conducted in MAR-MAY 2023, water samples were collected from multiple sites along the river, and categorized into upper, middle, and lower stretches. The findings revealed differing levels of suitability for various purposes among the sampled sites within each stretch. Parameters for drinking water quality generally adhered to specified limits across all stretches, except for E. coli, emphasizing the importance of disinfection measures. Moreover, the study evaluated irrigation suitability, with most sites falling within the good to excellent range, albeit some exhibiting elevated sodium levels, particularly in the lower stretch. Analysis of major ion abundance revealed an alkaline nature dominated by sodium and potassium ions over calcium and magnesium ions across all stretches. Heavy metal concentrations were either within specified limits or absent, indicating minimal industrial pollution. However, caution is warranted regarding industrial applications due to water aggressiveness, as suggested by indices such as the Langelier saturation index and Ryznar stability index, which hint at potential corrosion issues. Water quality in the Ganga River in India exhibited variability across the upper, middle, and lower stretches, with each segment presenting unique characteristics and suitability levels. Continuous monitoring and control measures, especially concerning the most probable number (MPN) of contaminants, are imperative to ensure the sustainability of water quality and meet the diverse usage needs along the river. The evaluation of Gangetic water from the Upper, Middle, and Lower Ganga Rivers is crucial for understanding water quality in one of Indias vital river basins. This study assesses physical, chemical, and biological parameters to determine suitability for drinking, irrigation, and aquatic life. Factors like pH, dissolved oxygen, turbidity, nutrients, heavy metals, and microbial load are analyzed to reveal water quality and potential risks. Temporal and spatial variations, influenced by natural processes and human activities, are explored. The findings aid in sustainable water management and conservation in the Gangetic basin, addressing the urgent need to safeguard this critical resource.

microbiology↗

Gene expression differences associated with intrinsic hindfoot muscle loss in the jerboa, Jaculus jaculus

Vertebrate animals that run or jump across sparsely vegetated habitats, such as horses and jerboas, have reduced the number of distal limb bones, and many have lost most or all distal limb muscle. We previously showed that nascent muscles are present in the jerboa hindfoot at birth and that these myofibers are rapidly and completely lost soon after by a process that shares features with pathological skeletal muscle atrophy. Here, we apply an intra- and inter-species approach, comparing jerboa and mouse muscles, to identify gene expression differences associated with the initiation and progression of jerboa hindfoot muscle loss. We show evidence for reduced Hepatocyte Growth Factor (HGF) and Fibroblast Growth Factor (FGF) signaling and an imbalance in nitric oxide signaling; all are pathways that are necessary for skeletal muscle development and regeneration. We also find evidence for phagosome formation, which hints at how myofibers may be removed by autophagy or by non-professional phagocytes without evidence for cell death or immune cell activation. Last, we show significant overlap between genes associated with jerboa hindfoot muscle loss and genes that are differentially expressed in a variety of human muscle pathologies and rodent models of muscle loss disorders. All together, these data provide molecular insight into the mechanism of evolutionary and developmental muscle loss in jerboa hindfeet.

developmental biology↗