Biology subjects

Joshi, A.

Publications and source records attributed to Joshi, A..

At least 37 records · Page 2Linked to original sources

bioRxiv2025

Out of sight, out of mind: Removal of predators by fisheries alters reef fish behaviour.

Pervasive human activities have led to the extirpation of predator species in many ecosystems. Understanding the extent and mechanisms by which such predator loss influences prey behaviour is critical for predicting the ecological consequences of trophic downgrading. We investigated reef fish behaviour in response to predator presence within and outside a protected area in the South Andaman Islands, India. We used 3D printed models to simulate the presence of two different types of predators; a sit-and-wait predator, a grouper (Mycteroperca rosacea) and a wide-ranging pursuit predator, a barracuda (Sphyraena barracuda). We recorded foraging, vigilance, and movement behaviours of herbivorous and invertivorous fish encountered in each plot. Overall, we found that fish were significantly more vigilant in response to both predator models compared to a non-predator control within protected areas but not outside protected areas. Foraging behaviour was suppressed by the predator treatments; however, herbivorous and invertivorous fish responded differently within protected areas. Fish movement behaviours also differed across predator treatments, prey foraging guilds, and areas. Anti-predator responses are thus highly contingent on habitat and both predator and prey traits. We highlight how the selective removal of predators by humans alters predation risk for prey and hence their risk-sensitive behaviours.

ecology↗

bioRxiv2025

Local extraction of predatory fish may initiate behaviourally mediated trophic cascades in coral reefs in the Andaman Islands.

Humans disproportionately target predators due to their higher economic and social value. This has led to widespread declines of predators in ecosystems worldwide leading to far-reaching effects on ecosystem processes. We investigate how the loss of predators from nearshore ecosystems due to fishing affects individual prey behaviour using a gradient of protection as a natural experiment. We collected data on piscivorous predator assemblages, reef habitats and prey behaviour within and outside two marine protected areas (MPAs) in the South Andaman Islands, India. As expected, predator abundance was significantly greater within MPAs. Similarly, we found greater coral cover and reduced algal cover within MPAs. In response, prey species, which included herbivorous and invertivorous fish, exhibited reduced movement and heightened vigilance inside MPAs. Additionally, prey individuals foraged at higher rates within MPAs. Habitat complexity and resource availability had complex effects on prey behaviours that varied across guilds. Our findings suggest that fishing directly alters the seascape of fear through the removal of predators. Fishing may also shape prey behaviour and ecological interactions indirectly through habitat degradation. Overall, this study highlights the need to study both direct and indirect consequences of human interactions with wild animals to understand their combined impacts on ecosystems.

ecology↗

bioRxiv2025

Programmable DNA-Silk fibroin hydrogel scaffold with temporal mechanical reinforcement for mesenchymal stem cells differentiation and accelerated wound healing in a full-thickness skin defect mice model

DNA-based hydrogels have attracted significant attention in biomedical applications due to their programmability, biocompatibility, and tunable functionalities. However, their clinical translation is hindered by high synthesis costs, limited mechanical strength, poor stability, and complex synthesis protocols. In this work, we present a novel DNA-silk fibroin hybrid hydrogel that overcomes these limitations by combining the unique biofunctionality of DNA with the superior mechanical and chemical properties of silk fibroin. Salmon-derived DNA, an abundant and low-cost source, was incorporated with silk fibroin to form hybrid networks via a simple, scalable process. Silk fibroin served as a robust scaffold, enhancing mechanical strength, controlling degradability, and improving structural stability, while the entangled DNA-silk network reduced rapid DNA degradation. The resulting hybrid hydrogel demonstrated temporal mechanical reinforcement and prolonged stability, with in vitro studies demonstrating that the developed hybrid hydrogel enhanced the chondrogenic and osteogenic differentiation of Infrapatellar Fat Pad Mesenchymal Stem Cells (IFP-MSCs). Additionally, hemostatic and in vivo studies demonstrated the potential of DNA-silk fibroin hydrogel as a promising biomaterial for rapid hemostasis and accelerated wound healing. Overall, the developed DNA-silk fibroin hybrid hydrogel offers strong potential for mesenchymal tissue engineering, hemostatic adjuvant and wound healing.

bioengineering↗

bioRxiv2025

Quantum Algorithm for Metabolic Network Analysis

Biological systems, such as cellular metabolism, involve thousands of reactions that together determine how cells grow, respond to their environment, and produce energy. Modeling and analyzing these systems require solving very large mathematical problems that can quickly become computationally prohibitive. To address this challenge, we present a quantum algorithm to analyze metabolic networks, focusing on flux balance analysis as a representative case. We use a quantum interior point method consisting of a quantum subroutine for matrix inversion. Specifically, we reformulate the metabolic optimization problem for efficient execution on a quantum computer using quantum singular value transformation, enabling a rapid solution of complex systems that arise in flux balance analysis. This quantum approach offers a potential computational advantage over classical interior point methods for large and well-conditioned networks. We demonstrate the practical applicability of our method with numerical simulations on the glycolysis and tricarboxylic acid (TCA) cycle network and show that the quantum solution converges to the correct biological objective. This work represents the first application of quantum algorithms to metabolic pathway analysis, establishing a new direction for quantum computational biology and paving the way for quantum approaches to large-scale biological optimization.

systems biology↗

bioRxiv2025

Deciphering the intra-tissue specific Collagen PTMs site-specific heterogeneity in Human Adrenal extracellular-matrix

The human adrenal is one of the pivotal glands of the endocrine system. Recently, the extracellular matrix (ECM) of the adrenal capsule and cortex was explored by dividing them into two fractions: outer (OF) and inner (IF). A significant variation in the levels of ECM proteins, including collagens, was documented. During the biosynthesis of collagen, it undergoes a plethora of PTMs exhibiting crucial roles such as cell-matrix interaction, adhesion, crosslinking, stability, etc. However, the site-specific identification and characterization of collagen PTMs remained challenging and is unknown for the human adrenal gland. We applied our in-house developed proteomics pipeline to identify several PTMS in 25 collagen chains from human adrenal-ECM. In the entire collagenome, we identified a total of 963 4-hydroxyproline (4-HyP), 201 3-hydroxyproline (3-HyP), 105 hydroxylysine (HyK), 17 galactosyl-hydroxylysine (G-HyK), and 35 glucosyl galactosyl-hydroxylysine (GG-HyK) sites. Although the site-specificity of collagen PTMs (3-HyP, HyK, G/GG-HyK) across fractions is conserved, the occupancies were different in a site-specific manner. Classically, a fully 3-hydroxylated site (P1164) of COL1A1 associated with osteogenesis imperfecta was found to be approximately fully hydroxylated ([~]99%) across fractions. Similarly, we also looked at the microheterogeneity of lysine modifications on one lysine residue (K862) of COL1A1. We observed that the hydroxylation level was higher in OF, while glycosylation levels were higher in IF. This may suggest a change in the crosslinking of collagen I across both fractions. Further, our analysis revealed much higher site-specific O-glycosylation in basement membrane collagen-IV, potentially facilitating the secretion of steroids from the adrenal gland. For the first time, we have annotated the collagen PTMs, developed a COL1A1 PTM map, and quantitated site-specific PTMs in the human adrenal gland. Taken together, this work revealed that intra-tissue-specific site-specific PTM collagen heterogeneity and lay the foundation for understanding their role in region-specific functions.

biochemistry↗

bioRxiv2025

CTG clade-specific proteins of the RSC chromatin remodeling complex regulate cell cycle progression of a critical priority fungal pathogen, Candida albicans

The RSC and the homologous chromatin remodeling complexes are known to regulate cell cycle progression in various organisms, including Saccharomyces cerevisiae, Drosophila, and Homo sapiens. In this work, we characterized the role of two novel CTG clade-specific proteins (Nri1 and Nri2) of the RSC complex in the regulation of cell cycle progression in a critical priority fungal pathogen, Candida albicans. We observed that Nri1, alone or along with Nri2, regulates cell cycle progression at multiple stages. The nri1{Delta}/{Delta} and nri1{Delta}/{Delta} nri2{Delta}/{Delta} mutants exhibited transient cell cycle arrest, defective spindle morphology, and cytokinesis. Transcriptomic analysis supported these mutant phenotypes and indicated a broad role of Nri proteins in the cell cycle. From our results, we conclude that Nri proteins are crucial for C. albicans proliferation and fitness. ImportanceThe composition of the essential RSC chromatin remodeling complex exhibits species-specific divergence, harboring unique subunits with distinct functions. In this study, we report that two fungal CTG clade-specific proteins of the C. albicans RSC complex, namely Nri1 and Nri2 can promote C. albicans fitness through regulating its cell cycle progression at multiple stages. Fitness defect along with stressor sensitivity and differential expression of the genes regulating pathogenesis in the nri mutants indicate potentiality of the Nri proteins as anti-Candida drug targets.

cell biology↗

bioRxiv2025

Heterotic Pooling Strategy for Enhanced Hybrid Performance in Bitter Gourd (Momordica charantia L.)

Bitter gourd (Momordica charantia L.), a crop of significant nutritional and medicinal renown, is experiencing a surge in global demand, particularly in Asia. To meet this demand amidst the challenge of limited agricultural land, enhancing productivity through innovative breeding is essential. Hybrid breeding, which harnesses the power of heterosis, offers a proven strategy for boosting crop yields. However, the success of any heterosis breeding program, especially in a naturally cross-pollinated and genetically variable crop like bitter gourd, is fundamentally dependent on robust methods for assessing and strategically utilizing the available genetic diversity. This study compared the efficacy of traditional morphological trait-based clustering with a modern breeding value-based method (Heterotic grouping based on Specific and General Combining Ability - HSGCA) for predicting heterosis. Eleven diverse bitter gourd inbred lines were crossed in a half-diallel fashion to generate 55 F1 hybrids. The hybrids and parents were evaluated for key yield-related traits. K-means clustering based on morphological data resulted in five groups but proved unreliable for predicting heterosis, as high heterosis was often observed within clusters. In contrast, HSGCA-based clustering organized the lines into three coherent groups, where crosses between the two main groups (Group 1 and Group 2) consistently exhibited significantly higher mid-parent (20.89%) and better-parent (7.5%) heterosis compared to intra-group crosses. The HSGCA method provides a far more reliable framework for defining heterotic groups in bitter gourd, enabling more efficient and predictive hybrid breeding programs.

plant biology↗

bioRxiv2025

Disruption of theta-timescale spiking impairs learning but spares hippocampal replay

The ability to rapidly learn and retrieve salient information about new environments is critical for survival. In mammals, the hippocampus plays a crucial role in that learning. Specialized features of hippocampal population coding, including network-level theta oscillatory activity, location-specific firing of principal cells, and reactivation of experience during immobility (replay), have been implicated in rapid storage and retrieval of spatial information. Disruptions of theta and replay jointly, or replay alone, are sufficient to impair learning; however, the specific contribution of theta-associated temporal structure during locomotion remains unknown. In this study, we manipulated hippocampal spiking activity in rats specifically during locomotion by optogenetically activating septal parvalbumin-expressing GABAergic neurons. We developed a closed-loop, theta phase-specific stimulation protocol that reliably reduced theta power shortly after stimulation onset. This manipulation preserved the place codes of individual cells but disrupted the fine temporal structure of endogenous spatio-temporal representations (i.e., theta sequences) at the pairwise and population level. Theta disruption during locomotion was also sufficient to cause pronounced deficits in learning the more cognitively challenging component of a spatial alternation task, even though disruption was applied on only [~]66% of trials. Notably, network effects accompanying theta disruption were restricted to locomotor periods; we did not observe changes in replay rate, length, or content during immobility. Together, these results demonstrate the importance of the precise temporal microstructure of locomotion-associated spatial representations in the hippocampus for learning.

neuroscience↗

bioRxiv2025

Allo-defensive, multiplex base-edited, anti-CD38 CAR T cells for "off-the-shelf" Immunotherapy

Chimeric antigen receptor (CAR) T cell therapies are being widely investigated in both autologous and allogeneic settings, with gene editing providing new strategies to address barriers to mismatched cell therapies. Currently universal donor derived T cell therapies require intensive lymphodepletion and are prone to host-mediated rejection. CD38, a transmembrane glycoprotein involved in cell activation and bioenergetics, is a promising immunotherapy target for haematological malignancies. Disruption of CD38 expression using base editing prevented fratricide between T cells expressing anti-CD38 CAR (CAR38). Additional base editing enabled generation of a universal donor CAR38-T cells, devoid of endogenous TCR{beta} and Human Leukocyte Antigen (HLA) molecules after disruption of T Cell Receptor Beta Constant (TRBC), Beta-2 microglobulin (B2M), and Regulatory Factor X5 (RFX5). Removal of cell surface HLA expression enabled evasion of anti-HLA antibodies in sera from sensitised donors and reduced allo-stimulation in mixed lymphocyte cultures (MLCs), while TCR{beta} disruption prevented allo-reactivity. In MLCs, CAR38 expression enabled potent allo-defense activity against CD38+ allo-reactive cells. Multiplex-base-edited CAR38-T cells exhibited antigen-specific anti-leukemic activity against human B, T, and myeloid malignancies and inhibited disease progression in humanised murine xenograft models. CAR38-T cells offer a potent off-the-shelf strategy against CD38+ haematological malignancies and plasma cells associated with autoimmunity.

immunology↗

bioRxiv2025

The olfactory bulb reflects structural plasticity within a genetically stable olfactory network

The olfactory bulb (OB), the first central relay of the olfactory pathway, plays a critical role in odor perception and exhibits remarkable structural plasticity shaped by environmental influences. This raises a fundamental question about the extent to which the structure of the OB is genetically determined. While both OB volume and function have been implicated in a range of neurodegenerative and neuropsychiatric disorders, such as Parkinsons disease, schizophrenia, and depression, all of which involve known genetic risk factors, the heritability of the OB structure remains poorly understood. Here, we investigated the heritability of OB volume and the broader olfactory network architecture in a large sample of healthy young adults (n = 941; aged 22-35 years), including monozygotic and dizygotic twin pairs. Using a deep learning-based segmentation model, we first automatically segmented OB volumes and then employed a support vector machine framework to classify zygosity based on within-pair morphological similarity. The OB volume alone showed weak classification performance in distinguishing between monozygotic and dizygotic twins, suggesting limited heritability. However, integrating OB volume with morphometric features from olfactory-associated brain regions, including the hippocampus, parahippocampal gyrus, entorhinal cortex, and medial orbitofrontal cortices, substantially improved classification performance. This effect was specific to the olfactory network, underscoring the distributed nature of genetic influence in this system. These findings suggest that the OB, despite being a highly plastic and environmentally responsive structure, is embedded within a genetically coordinated neural network.

neuroscience↗

bioRxiv2025

Molecular identification and functional analysis of HrpZ2, a new member of harpin superfamily from Pseudomonas syringae inducing hypersensitive response in tobacco.

Harpins belong to a group of proteins with distinctive features such as heat stability, glycine richness, and absence of cysteine, and are secreted by many Gram-negative phytopathogens via the type III secretion system. Harpins are known to trigger hypersensitive response followed by induction of systemic acquired resistance in non-host plants. However, the molecular mechanism of harpin-induced hypersensitive response remained largely unexplored, mainly because of lack of structural information. In this study, we report the cloning of a new harpin gene (hrpZ2) from Pseudomonas syringae strain MTCC-11950, belonging to the harpin superfamily. In silico analysis revealed that about 50.29% of the protein consists of alpha-helices, 48.53% are random coils, and only 1.16% are beta-sheets, and nearly half (42%) of the protein consists of intrinsically disordered regions. Based on a prokaryotic predictive model and the presence of a signal peptide on its N-terminus, the subcellular localization of harpin is predicted as extracellular. To date, no experimentally determined crystal structure of any harpin protein is available. Therefore, we built and validated a three-dimentional model (with 99% of residues in allowed/additionally allowed regions and a Z-score of -5.3) of harpin. Phylogenetic analysis and functional domain studies revealed that this new harpin belongs to the harpin superfamily. Infiltration of harpin in tobacco leaves resulted in hypersensitive response, which was associated with oxidative burst, callose deposition, localized cell death, and increased activity of defense-related enzymes such as phenylalanine ammonia-lyase and polyphenol oxidase. Furthermore, infiltration of harpin in non-host plants from different angiosperm families induced hypersensitive response, indicating broad-spectrum agricultural applicability of this new harpin protein. This study elucidates the molecular and functional properties of the new harpin protein and its ability to induce hypersensitive response across a broad range of non-host plants.

plant biology↗

bioRxiv2025

Understudied and underprotected: biodiversity and conservation challenges in the Konkan region of Maharashtra

In biodiversity hotspots, such as the Western Ghats, periodic synthesis of existing ecological research can help identify knowledge gaps and address critical threats to biodiversity. The Maharashtra part of the Konkan region, situated between the Sahyadri foothills and the west coast, with diverse tropical vegetation, harbours unique open ecosystems, such as lateritic plateaus, and supports a multitude of threatened species, including hornbills and tigers. However, the region remains relatively understudied and has not received adequate protection through state or national conservation policies and laws. The area is undergoing rapid human-driven land-use change. These activities can impact the regions biodiversity, necessitating an effort to identify knowledge gaps and critical threats. Through a combination of a literature review and focus group discussions with 44 participants from various institutions and non-governmental organisations, we synthesised existing published information on the Konkan region of Maharashtra and identified key research gaps and conservation challenges. Our review of 138 studies found that while agroforestry and human-wildlife interactions have received some research attention, the effects of climate change on the regions biodiversity remain poorly understood. Focus group discussions highlighted major threats, including land-use changes due to expanding monoculture plantations, clear-felling of forests, forest fires, environmental pollution, and rapid infrastructure development, which are leading to habitat loss and fragmentation. Some of these concerns were validated by publicly available regional data, which revealed a 30% increase in roads, a 14% expansion of cashew plantations, and associated forest loss. This synthesis offers valuable insights for government and non-governmental organisations to inform future research and conservation efforts in the region.

ecology↗

bioRxiv2025

Fitness effects of adult crowding in Drosophila: more than just overall density

Density-dependent selection has been widely studied in D. melanogaster in the context of larval crowding, revealing its impact on several life-history traits. However, the effects of adult crowding in Drosophila have not been studied in similar detail. Earlier studies on adult crowding have primarily used large flies (reared at low larval density). These gave rise to the notion that adult crowding negatively affects key fitness components such as mortality and fecundity. Earlier work from our lab showed that body size significantly alters how flies respond to a relatively short period of adult crowding. Large flies show increased mortality and decreased fecundity with increased adult density. In contrast, small flies (reared at high larval density) tolerate adult crowding better, showing increased fecundity with increased adult density. Here, we extend this line of work by investigating how air volume in a culture vial can influence the effects of adult crowding. We manipulated air volume by altering the vial diameter (thereby also the food surface area), or the height of the air column. Flies of different body sizes were generated by rearing them at low or high larval densities. We find that the surface area of food available to the adults plays a greater role in shaping the outcome of adult crowding than the height of the air column. Large flies displayed context-dependent responses to adult crowding that were driven by the surface area of food provided. Small flies consistently responded positively to adult crowding in all conditions, with low mortality and increased fecundity at high adult density. Our findings highlight the importance of considering the body size, absolute density and the food surface area available to the flies and their nuanced interactions while exploring the effects of adult crowding, and thus paves the way for a detailed examination of other factors that impact adult crowding in addition to just the overall density.

ecology↗

bioRxiv2025

Bigger is not always better: size-dependent fitness effects of adult crowding in Drosophila melanogaster

Density-dependent selection is an important factor shaping the evolution of life histories. In holometabolous insects, crowding in the larval and adult stages can have very different effects on key fitness components. While the nuanced effects of density-dependent selection through larval crowding in Drosophila melanogaster have been extensively studied for various life history traits, very few studies have investigated the effects of adult crowding in Drosophila. Moreover, these few studies were mostly conducted on large flies, derived from low larval density cultures, and typically treated the overall density of flies per culture container as an index of the strength of adult crowding. We hypothesized that the size of the adults should shape the impact of adult crowding, with small individuals experiencing less stress than large individuals when crowded. Consequently, the adverse fitness effects usually associated with adult crowding may not be observed for small individuals. We tested this hypothesis by subjecting flies of different sizes - regular-sized flies, and small flies derived via larval crowding or selection for rapid development to adulthood - to an episode of adult crowding and examining their mortality and fecundity. Thus, we explored the interactive effects between larval and adult crowding on key fitness components. Small body size enabled flies to handle adult crowding better, with significantly lower mortality under crowded conditions when compared to flies of large body size. Moreover, small flies showed a consistent pattern of increased fecundity upon adult crowding. This positive impact on fecundity was not observed when larger flies were crowded. It is clear from our study that the effects of adult crowding can be very nuanced and body size-specific, even to the extent of having a net beneficial effect on fitness components, contrary to previous belief.

ecology↗

bioRxiv2025

HUWE1 stimulates mTORC1 activity by enhancing Rheb interaction with mTORC1 and supports de novo pyrimidine synthesis

mTORC1 is a central regulator of cell growth that is directly activated by the small GTPase Rheb on the lysosomal membrane in response to growth factors. We recently reported that polyubiquitinated Rheb facilitates its interaction with mTORC1, leading to mTORC1 activation. However, the molecular mechanisms underlying the ubiquitination of Rheb and its interaction with mTORC1 for activation are not fully understood. In this study, we demonstrate that HUWE1, an E3 ubiquitin ligase, preferentially interacts with ubiquitinated Rheb and is essential for the interaction between Rheb and mTOR, as well as for mTORC1 activation. Additionally, HUWE1 is necessary for Rheb to interact with CAD, a crucial enzyme involved in de novo pyrimidine biosynthesis, and for its activation through the mTORC1-S6K1 pathway. Knocking down HUWE1 in cultured cells or in the liver tissues of mice inhibits mTORC1 activity without affecting the phosphorylation of Akt or TSC2, nor does it affect the lysosomal localization of TSC2 or mTORC1. Furthermore, HUWE1 specifically enhances the expression of CAD without influencing other enzymes involved in de novo pyrimidine synthesis and maintains UMP levels in the hepatocytes of liver tissues. These findings indicate that HUWE1 serves as a key organizer of the Rheb ubiquitin complex, amplifying mTORC1 activity and playing a vital role in stimulating de novo pyrimidine synthesis by enhancing CAD expression and activity. HighlightsO_LIHUWE1 and CAD preferentially interact with ubiquitinated Rheb. C_LIO_LIHUWE1 further ubiquitinates Rheb and supports Rheb interaction with mTORC1 and CAD. C_LIO_LIHUWE1 stimulates mTORC1 activity through its E3 ligase activity. C_LIO_LIHUWE1 also supports pyrimidine synthesis by enhancing CAD expression. C_LI

biochemistry↗

bioRxiv2025

GenDiS3 database: census on prevalence of protein domain superfamilies of known structure in the entire sequence database

Despite the vast amount of sequence data available, a significant disparity exists between the number of protein sequences identified and the relatively few structures that have been resolved. This disparity highlights the challenge in structural biology to bridge the gap between sequence information and three-dimensional structural data, and the necessity for robust databases capable of linking distant homologues to known structures. Studies have indicated that there is a limited number of structural folds, despite the vast diversity of proteins. Hence, computational tools can enhance our ability to classify protein sequences, much before their structures are determined or their functions characterised, thereby bridging the gap between sequence and structural data. GenDiS is a repository with information on Genomic Distribution of protein domain superfamilies, involving a one-time computational exercise to search for trusted homologues of protein domains of known structures against the vast sequence database. We have updated this database employing advanced bioinformatics tools, including DELTA-BLAST for initial detection of hits and HMMSCAN for validation, significantly improving the accuracy of domain identification. Using these tools, over 151 million sequence homologues for 2060 superfamilies (SCOPe) were identified and 116 million out of them were validated as true positives. Through a case study on glycolysis-related enzymes, variations in domain architectures of these enzymes are explored, revealing evolutionary changes and functional diversity amongst these essential proteins. We present another case, LoG gene, where there one can tune-in and find significant mutations across the evolutionary lineage. The GenDiS database, GenDiS3, and the associated tools made available at https://caps.ncbs.res.in/gendis3/, offer a powerful resource for researchers in functional annotation and evolutionary studies. Database URL: https://caps.ncbs.res.in/gendis3/

bioinformatics↗

bioRxiv2025

Exploring Microbial Dynamics: The Role of Commensals in Healthy and Dandruff-Affected Scalps

The human scalp harbors a diverse microbial community that plays a crucial role in scalp health and disease. This study aimed to analyze the microbiome of both healthy and dandruff-affected scalps to elucidate microbial composition differences and potential associations with dandruff pathology. Samples were collected from three healthy and three dandruff-affected individuals, and the V4 region of the 16S rRNA gene and the ITS1 region were sequenced to characterize bacterial and fungal communities, respectively. Taxonomic analysis identified 5 dominant phyla and 31 genera within the samples, revealing a shift from Actinomycetota dominance in healthy scalps to Basidiomycota dominance in dandruff-affected scalps. Notably, the fungal phylum Ascomycota, including Malassezia, was also more abundant in dandruff-affected scalps. This transition emphasizes the intricate interactions among microbial communities and their potential impact on scalp health. These findings suggest specific microbial shifts are associated with dandruff, highlighting the potential for targeted therapeutic strategies that modulate the scalp microbiome to improve scalp health. Further research is needed to elucidate the specific interactions between these microbial groups and their impact on scalp health.

microbiology↗

bioRxiv2025

Morphological Variation and DUS Characterization in Bitter Gourd (Momordica charantia L.) collections from Eastern India for Varietal Identification and Genetic Improvement

This study investigates the morphological variation and Distinctness, Uniformity, and Stability (DUS) characterization of Momordica charantia collections from Eastern India to facilitate varietal identification and genetic improvement. Twenty-two Bitter Gourd varieties were characterized based on morphological traits to assess genetic diversity and enhance breeding program efficiency. Significant variations were observed in fruit morphology (colour, length, surface tubercles, and ridges) and seed characteristics (Colour and margin indentation) enabling effective varietal differentiation. Notably, four accessions were classified as M. charantia var. muricata due to their distinctly small fruit size, highlighting the presence of diverse morphological forms within the studied population. Additionally, admixture was detected in seven varieties, which underscores the necessity for purification processes to ensure the commercial viability of these accessions. This research emphasizes the rich genetic diversity of Bitter Gourd in Eastern India and identifies key traits that are essential for distinguishing between varieties. The findings provide valuable insights for breeders to develop improved cultivars with enhanced productivity and consumer-preferred traits. Moreover, this study supports ongoing plant breeding efforts to enhance crop quality and yield by identifying reliable morphological traits for varietal differentiation. Furthermore, it recommends additional research to refine DUS criteria by incorporating more traits that effectively differentiate between smooth-type Bitter Gourd varieties.

genetics↗