Biological Science: Research Developments and Innovations Vol. 3

Structure, Function and Dynamics of the Eukaryotic Cell: A Critical Narrative Review of Mesoscale Organisation and the Methods that Define It

Shakib Uzzaman — 2026-09-17

Cell biology has undergone a conceptual reorientation over the past decade. The textbook picture of the cell as a set of stable, membrane-delimited compartments linked by vesicular traffic has been supplemented, and in places displaced, by a picture of graded, dynamic and physically heterogeneous organisation in which membraneless assemblies, persistent inter-organelle contacts, mechanical force transmission and continuous molecular turnover are treated as primary organising principles. This review examines the strength of the evidence underlying that reorientation. Peer-reviewed literature on eukaryotic subcellular organisation was identified through structured searching of biomedical and multidisciplinary scholarly sources, supplemented by citation tracking and by consultation of methodological and consensus statements, with an emphasis on work that tests rather than assumes the prevailing framework. The synthesis is organised around five themes: the physical environment of the cytoplasm and the vocabulary used to describe subcellular order; membraneless compartmentalisation and the contested status of liquid–liquid phase separation as an in-cell mechanism; the reconceptualisation of organelles as an interacting system defined by contact sites and shared lipid and ion fluxes; mechanical continuity between the extracellular environment, the cytoskeleton and the nucleus; and the measurement technologies that generate the current evidence base. Across these themes the same interpretive weakness recurs. Mechanisms established in reconstituted or strongly perturbed systems are frequently transferred to the intact cell without the demonstrations of necessity, sufficiency and physiological scaling that such transfer requires. Confidence is highest where in-cell structural observation, quantitative perturbation and independent replication converge, as for contact-site tethering, actin network mechanics and mitochondrial remodelling. Confidence is substantially lower for claims that particular condensates perform specific biochemical functions, for cell-type definitions derived from transcript abundance alone, and for causal accounts of mechanical signalling built on stiffness ranges far outside tissue physiology. Priorities for the next phase of work include the development of endogenous-level, reversible perturbations, the routine reporting of physical parameters alongside molecular ones, and the extension of in-cell structural methods beyond a narrow set of cultured mammalian lines.

Deciphering the Molecular Nexus: Phytohormone Networks and ROS Signaling in Combined Heat and Biotic Stress

Pragun Pal — 2026-09-17

Climate warming increasingly exposes plants to heat episodes while they are simultaneously challenged by pathogens and herbivores. These combinations cannot be understood as the arithmetic addition of heat and biotic stress because both perturb the same signalling infrastructure, particularly phytohormone networks and reactive oxygen species (ROS). This critical narrative review evaluates how these networks are rewired during combined heat and biotic stress, with emphasis on salicylic acid (SA), jasmonate (JA), abscisic acid (ABA), ethylene, growth-related hormones, respiratory burst oxidase homologues, calcium-dependent signalling, redox control, and temperature-sensitive immune transcriptional modules. Literature published from 2000 to 4 July 2026 was considered, with earlier seminal studies retained where mechanistically necessary. The evidence is strongest for temperature-sensitive SA immunity in Arabidopsis, where warm conditions can suppress defence-associated GBPL3 condensate formation and the CBP60g–SARD1 transcriptional module, reducing local SA production and systemic N-hydroxypipecolic acid-dependent acquired resistance. ROS emerge not as a single oxidative variable but as compartment-, amplitude-, and time-dependent signals that connect pattern recognition, intracellular immune receptors, stomatal behaviour, thermotolerance and systemic acclimation. JA and ABA illustrate consequential trade-offs: signalling that protects against herbivory or water loss can compromise transpirational cooling or temperature-sensitive resistance, depending on context. Evidence from tomato, apple and other crops also shows that warming can enhance, suppress or qualitatively redirect defence according to thermal regime, tissue exposed, attacker lifestyle, host genotype and pathogen thermophysiology. The central limitation of the field is therefore not lack of candidate components, but inadequate resolution of their spatiotemporal interactions under realistic stress sequences. Future progress requires factorial heat–biotic experiments, cell-resolved redox and hormone measurements, simultaneous host–attacker phenotyping and conditional engineering of integrator nodes rather than constitutive activation of defence.

Antimicrobial Stewardship in Dairy Production: Selective Therapy, Resistance Dynamics and One Health Strategies

Shweta Kelkar — 2026-09-17

Antimicrobial stewardship in dairy production must reconcile two legitimate objectives: timely treatment of bacterial disease to protect animal health and welfare, and reduction of avoidable antimicrobial exposure that can select for resistance within animals, herds and connected environments. This critical narrative review evaluates selective therapy, antimicrobial-resistance dynamics and One Health strategies across the dairy production system. Literature published from 1 January 2000 through 4 July 2026 was identified through live searches of scholarly databases and indexes, supplemented by citation searching and authoritative institutional sources. Evidence is strongest for selective dry-cow therapy in appropriately selected herds and for culture-guided selective treatment of non-severe clinical mastitis. Randomised trials and meta-analyses show that substantial reductions in intramammary antimicrobial use can be achieved without materially compromising udder-health outcomes when eligibility criteria are robust and, in most evidence bases, internal teat sealants protect untreated healthy quarters. The resistance consequences are less linear. Herd-level intramammary use is not consistently associated with resistance in milk-associated commensals, whereas systemic exposure has shown clearer associations with multidrug resistance in non-aureus staphylococci and faecal Escherichia coli. Preweaned calves represent a distinct amplification compartment because direct treatment, age-related microbiome dynamics and feeding of milk containing antimicrobial residues can increase carriage or shedding of resistant bacteria. Manure and farm-environment studies demonstrate persistence and movement of resistance determinants, but direct attribution of human infections to dairy-origin resistance remains difficult. Effective stewardship therefore requires more than reducing treatment counts: it depends on disease prevention, rapid diagnostics, route- and class-sensitive prescribing, calf and waste-milk management, environmental controls, comparable use and resistance metrics, veterinary oversight, worker competence and policy structures that preserve therapeutic access. The most defensible One Health strategy is consequently a risk-based system that reduces unnecessary exposure while maintaining prompt, evidence-based treatment of animals that are likely to benefit.

Beyond Colostrum: Transition Milk, Passive Immunity and Precision Nutrition in the Neonatal Dairy Calf

Eshita — 2026-09-17

The first hours of life establish a disproportionate share of the health trajectory of the dairy calf. Management has therefore centred appropriately on timely delivery of high-quality first-milking colostrum and successful transfer of passive immunity. Yet this focus has also encouraged an artificial nutritional boundary: once the first colostrum meals are completed, many calves move abruptly to whole milk or milk replacer even though mammary secretion changes progressively through transition milk before mature milk is reached. This critical narrative review evaluates the biological and practical significance of that post-colostral interval, integrating evidence on immunoglobulin transfer, transition-milk composition, intestinal development, local mucosal defence, growth, health, processing and precision feeding. Literature published from 1 January 1990 to 5 July 2026 was appraised, with earlier seminal studies retained where necessary. The evidence is strongest for a hierarchical interpretation. First-milking colostrum remains the irreplaceable intervention for systemic immunoglobulin G acquisition because absorptive efficiency declines rapidly after birth. Transition milk cannot reliably correct inadequate systemic passive immunity once macromolecular absorption has closed. Its potential value instead shifts towards nutrient density, luminal immunological activity and trophic effects on the developing intestine. Controlled studies generally support enhanced intestinal growth when colostrum-rich or transition-milk diets are extended for several days, while effects on preweaning growth and disease are less consistent and are frequently confounded by unequal energy, protein, immunoglobulin concentration, microbial exposure and comparator quality. Recent compositional work further shows that transition milk is a dynamic matrix containing changing concentrations of immunoglobulins, lactoferrin, insulin-like growth factor I, oligosaccharides, fatty acids and diverse proteins, but component abundance should not be equated with demonstrated causal benefit. A precision-nutrition framework should therefore begin with verified passive immunity, followed by measured transition-milk allocation, biosecurity and nutrient matching to calf size, environment and health. Closed-loop individualisation of transition-milk dose remains a research objective rather than an established standard. The most credible future progress will come from component-resolved, isoenergetic trials and multisite field studies that separate nutritional from bioactive effects.

Crop Wild Relatives and Global Genebanks for Climate-Resilient Agriculture: From Genomic Discovery to Pre-Breeding

Ashutosh Gautam — 2026-09-17

Crop wild relatives (CWRs) retain evolutionary variation that was incompletely captured during domestication and subsequent crop improvement, making them strategically important for climate adaptation. Their value, however, depends on a chain of activities that begins with conservation and accession identity, continues through genomic and phenotypic discovery, and culminates in pre-breeding and cultivar-relevant validation. This critical narrative review evaluates that chain rather than treating conservation, genomics and breeding as separate domains. Literature published from 1997 to 5 July 2026 was examined through open scholarly indexes, agricultural and life-science databases, citation searching and authoritative institutional sources. Evidence was appraised for biological relevance, experimental design, genetic resolution, environmental realism, reproducibility and proximity to breeding deployment. The literature strongly supports the proposition that CWRs can supply alleles for stress tolerance, disease resistance, root architecture and quantitative productivity traits, but it also shows that useful diversity is unevenly conserved and often poorly connected to phenotypic evidence. Global genebanks provide indispensable long-term infrastructure, yet accession redundancy, taxonomic uncertainty, regeneration biology, incomplete passport information and uneven safety duplication can reduce practical value. Genebank-scale genotyping, pangenomics, landscape genomics and high-throughput phenotyping are improving the identification of candidate donors and adaptive loci, but reference bias, structural variation, population structure and genotype-by-environment interaction limit simple prediction from sequence to field performance. Introgression libraries and marker-assisted pre-breeding remain the most mature routes for transferring wild alleles, whereas genome editing and de novo domestication are promising but are supported mainly by proof-of-concept evidence. The central conclusion is that climate-resilient use of CWRs is constrained less by the existence of diversity than by discontinuities between conservation, data systems, phenotyping, pre-breeding and target-environment validation. The highest-value future investments are therefore those that make this entire pipeline interoperable, representative and testable under realistic climate stresses.

Climate-Driven Harmful Algal Blooms and Aquaculture: Early Warning, Fish Mortality, Exposure Mechanisms and Farm Adaptation

Sangeeta Hansda — 2026-09-17

Harmful algal blooms (HABs) are a recurrent hazard to marine and freshwater aquaculture, yet the phrase ‘climate-driven HAB’ can obscure the diversity of taxa, mechanisms and environmental pathways involved. This critical narrative review evaluates how climate variability and long-term change alter bloom opportunity, how harmful algae translate into fish mortality, how farms are exposed, and whether monitoring and adaptation measures provide actionable protection. Peer-reviewed literature published from 1 January 2000 to 4 July 2026 was considered, with older material retained only where conceptually necessary. Evidence was synthesised across climate–bloom attribution, ichthyotoxic mechanisms, operational early warning, aquaculture risk and mitigation. The strongest evidence indicates that warming can expand growth windows or geographic niches for some harmful taxa, while hydroclimatic extremes, stratification, altered flushing and nutrient delivery can trigger severe regional events. These relationships are not universal: corrected global event datasets do not support a uniform worldwide increase, and cold-adapted fish-killing taxa illustrate why species- and region-specific attribution is essential. Fish mortality is likewise mechanistically heterogeneous. Gill injury, direct contact toxicity, reactive oxygen species, lipid-derived compounds, pore-forming toxins and oxygen stress may act alone or in combination, with strong strain and host dependence. Early-warning capacity is improving through integrated microscopy, molecular assays, remote sensing, automated imaging and hydrodynamic forecasting, but technological detection is not equivalent to decision-useful warning unless thresholds, lead time and farm actions are locally validated. Evidence for farm adaptation is weaker than evidence for hazard detection: strategic siting, exposure avoidance and contingency planning are defensible, whereas reactive interventions such as clay treatment, pumping or other physical controls remain context dependent and incompletely evaluated at commercial scale. Freshwater cyanobacterial risks add chronic toxin exposure and eutrophication feedbacks to the acute fish-kill paradigm. The principal research need is therefore not a single universal HAB predictor or remedy, but validated, species-specific risk systems linking climate-sensitive hazard, exposure, fish vulnerability and feasible farm response.