Biology subjects

Dave, R.

Publications and source records attributed to Dave, R..

3 recordsLinked to original sources

bioRxiv2025

Fission or fusion: shoaling adaptations in green chromides (Etroplus suratensis) across multiple manipulations

Collective behaviour contributes towards increased fitness, however, in fission-fusion societies, the decision to participate in a group is based on cost-benefit ratio derived under a given condition. In todays world, this ratio dramatically changes due to increased challenges in degraded habitats, impacting behavioural decisions towards social grouping. In this paper, we used fish shoal as a unit of collective behaviour, and investigated variations in shoaling adaptations across a range of manipulations, mimicking challenges faced by the species under natural conditions. We used green chromides (Etroplus suratensis), a cichlid fish species, and characterised their shoaling behaviour under laboratory conditions for two group sizes, 4 and 8. We then examined the effects of different manipulations, for example, starvation and reduced space (both mimicking resource constrained conditions), and presence of hetero species including tilapia (Oreochromis sp., an alien species widespread within the habitats of E. suratensis) on their shoaling behaviour. Our results showed that E. suratensis formed shoals in both group sizes, 4 and 8. In subsequent analyses, we used group size 8 as a control and demonstrated that space reduction and starvation significantly impacted shoaling, reducing shoal splits and occurrences of solitary fish, while increasing incidences of single, cohesive shoals comprising all individuals. E. suratensis also formed mixed-species shoals with alien Oreochromis spp., but exhibited a large percentage (in absolute terms) of shoal splits. Overall, E. suratensis exhibited plasticity in their shoaling behaviour, and increased fusion of shoals under challenging conditions, which was in contrast to showing more fission in presence of the alien hetero species.

animal behavior and cognition↗

bioRxiv2024

Pathophysiological Implications of Nucleotide Self-Assembly: Adenine-Derived Nucleotides Aggregation in Disease Mechanisms

Adenine nucleotides, including adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate, play pivotal roles in cellular bioenergetics, nucleic acid metabolism, and signal transduction. However, their propensity to undergo self-assembly and form supramolecular aggregates under certain conditions is not well-characterized. In this study, we examined the self-assembly, aggregation, and cytotoxicity of AMP, ADP, and ATP in both fresh and aged conditions. Utilizing advanced microscopy techniques, Thioflavin T (ThT) fluorescence assays, and cross-seeding experiments, we identified oligomer formation in freshly prepared nucleotide solutions, which progressed to larger, more stable aggregates over time. The cytotoxic potential of these nucleotide aggregates was assessed using in vitro models, including human retinal pigment epithelial (RPE-1) and colorectal carcinoma (HCT-116) cell lines. Our findings demonstrate that nucleotide aggregation induces significant cytotoxic effects, particularly in aged conditions. Further investigations into bacterial toxicity models revealed similar deleterious impacts, indicating a broad-spectrum biological stress response to nucleotide aggregates. These results suggest that nucleotide self-assembly and aggregation may contribute to cellular dysfunction, offering new insights into their non-canonical roles in disease pathophysiology, potentially analogous to protein misfolding disorders.

bioengineering↗

bioRxiv2024

Assembly of branched chain amino acid (BCAA) to toxic fibrils may be related to pathogenesis of Maple syrup urine disease (MSUD)

Inborn errors of metabolism (IEMs) are a group of diseases caused by mutations in single genes, leading to the buildup of metabolites that are typically toxic or disrupt normal cellular function. The etiological relation of metabolic disorders has been uncovered through the study of metabolite amyloids. Various metabolites that accumulate in IEMs have been reported to self-assemble into organized structures. These structures exhibit similar physicochemical properties as proteinaceous amyloid fibrils. In this context, our study illustrated the aggregation properties of Branched chain amino acid (BCAA) i.e. Isoleucine, Leucine and Valine that accumulate in Maple syrup urine disease (MSUD) to investigate their propensities to assemble into amyloid-like fibrils. The structural morphologies of BCAA were studied via. microscopic techniques like Scanning electron microscopy (SEM), optical microscopy and phase contrast microscopy. Further, characterization techniques were employed to understand the physicochemical properties of the self-assemblies and its underlying mechanism. The amyloid-like nature of these aggregates was confirmed using Thioflavin T (ThT) and Congo Red (CR) assays, indicating a possible cytotoxic effect. The MTT assay reveals BCAAs were cytotoxic and significantly decrease cell viability. Our study plays a key role in understanding the physicochemical properties of MSUD in association to amyloid disease, possibly paving the way for the development of therapeutic solutions in the future. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=122 SRC="FIGDIR/small/616096v1_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@13f26daorg.highwire.dtl.DTLVardef@10fdef5org.highwire.dtl.DTLVardef@f6e1d7org.highwire.dtl.DTLVardef@64f608_HPS_FORMAT_FIGEXP M_FIG C_FIG The self-assembly of BCAA-Ile, Leu, Val was investigated and the findings indicate that their aggregation may follow an amyloidogenic pathway.

bioengineering↗