Faithful chromosome segregation requires the kinetochore, a macromolecular protein complex that assembles on centromeric chromatin. In vertebrates, centromere identity is epigenetically defined by the histone H3 variant CENP-A, whose nucleosomes are replenished during early G1 phase through a cell cycle-regulated deposition mechanism. The CENP-A chaperone HJURP is recruited to centromeres via the Mis18 complex to enable CENP-A incorporation (Mis18C pathway). Recent genetic analyses in chicken cells, however, revealed an additional, independent recruitment route via direct HJURP-CENP-C interaction (CENP-C pathway). Structural studies show that CENP-C and the Mis18C subunit KNL2/M18BP1 engage pre-existing CENP-A nucleosomes at different surfaces of the Constitutive Centromere-Associated Network (CCAN), constraining the spatial coordinates where new CENP-A is incorporated. This review summarizes current understanding of HJURP recruitment mechanisms for vertebrate CENP-A deposition and proposes that this structure-defined deposition geometry underlies epigenetic self-propagation of centromere positional information by maintaining proper CCAN spacing across cell divisions.

The mammalian heart is classically described as arising from two cardiac lineages, first and second. Yet, recent lineage tracing of Mesp1 mesoderm and live imaging show that cardiac progenitors are already partly biased toward specific heart regions during gastrulation, despite extensive cell mixing. We propose that cardiac fate is probabilistic, analogous to stochastic fate strategies in the retina. Epiblast cells carry probability distributions over fates that resolve during gastrulation into specific regional allocations. Reanalyzing a retrospective clonal dataset, we find that the clones do not single out one fixed lineage tree. Instead, the data permit a family of 361 distinct restriction topologies, none dominant, and only 40 of these are binary. Among the binary trees, the best-supported recover both where progenitors sit along the proximal-distal axis of the streak and the order in which they leave it, as recent prospective lineage tracing shows. Rather than replacing the first/second lineage concept, this framework shifts the focus from fixed lineage identity to fate probabilities. Testing this idea will require prospective live imaging from epiblast through heart tube formation.

Tumor evolution, from premalignant lesions to metastasis, is increasingly recognized as shaped by continuous interplay between tumor cells metabolism and their microenvironment. During tumor initiation, major oncogenic pathways drive early metabolic reprogramming of lipid, amino acid, and energy pathways to promote cell competition and clonal expansion. These metabolic changes reciprocally shape the tumor microenvironment (TME) through metabolite fluxes, extracellular matrix remodeling, and immune reprogramming, generating adaptive niches that sustain tumor progression and metastasis. Cancer cell metabolic adaptability becomes even more crucial to survive dissemination and adapt to a new, distant microenvironment. Here, we discuss these dynamic interplays and highlight the p53 pathway as an integrative hub linking oncogenic signaling, metabolic rewiring, and tumor microenvironmental adaptation throughout carcinogenesis. We will also outline how emerging technologies may redefine the TME-p53-metabolism interplay uncovering therapeutically exploitable metabolic vulnerabilities.

Homologous recombination (HR) is a DNA double-strand break repair pathway that preserves genome integrity by restoring genetic information lost through programmed or spontaneous DNA damage. As a template-directed process, HR identifies homologous DNA sequences to accurately repair broken chromosomes while minimizing inappropriate recombination events. Central to this process are the RecA-family recombinases. Most eukaryotes use Rad51 during mitosis and meiosis and Dmc1 during meiosis to locate and pair homologous DNA sequences. To ensure high-fidelity repair, eukaryotes have evolved regulatory protein networks that control recombinase filament assembly, organization, and strand exchange. Here, we review recent advances in understanding how recombinase filament length, architecture, and dynamics influence the fidelity and outcome of homologous recombination. We discuss their distinct roles in mitotic and meiotic recombination and propose how evolution has shaped filament properties to regulate interactions between donor and recipient DNA templates and promote accurate genome maintenance.

Euarthropods are characterized by segmented, sclerotized, and articulated bodies and appendages, expressed through arthrodization and arthropodization. Both are regarded as defining features of Euarthropoda and have been proposed to evolve in a specific sequence, during which arthropodization preceded arthrodization, and initiated in frontal appendages and was subsequently co-opted into other appendages. Here, we investigate their evolution across Ecdysozoa using morphological comparison, ancestral-state reconstruction (ASR), and semi-quantitative methods. Morphological comparisons and ASR reveal repeated gains, reductions, losses, and regional decoupling of segmentation, sclerotization, and articulation in both body and appendicular systems. Semi-quantitative indices indicate variable degrees of arthrodization and arthropodization across ecdysozoan lineages and do not show a progressive increase from the basal panarthropods and the stem-group euarthropods to crown-group euarthropods. Together, these results support a modular, convergent evolution of arthrodization and arthropodization in different lineages, probably through repeated modification, reduction, or redeployment of the ancestral developmental toolkit.

In humans, the FLOWER (FWE or CACFD1) gene encodes a set of small, alternatively spliced transmembrane protein isoforms (hFWE1-4). The canonical human isoform, hFWE4, and its various orthologues, which we collectively refer to as FWE for simplicity, assumes a four transmembrane pass structure with cytosolic N- and C-termini. This topology exposes YXXΦ motifs enabling interaction with trafficking machinery and positions highly-conserved cationic residues for interaction with membrane phospholipids. While identified initially as a mediator of synaptic vesicle endocytosis in presynaptic neurons, FWE is now recognized as a critical mediator of endo-lysosome related organelle (ELRO) trafficking across diverse cell types including cytotoxic T-lymphocytes and epidermal keratinocytes. A unifying feature of FWE function appears to be elevation of cytosolic Ca[2+] levels. However, the underlying molecular mechanisms remain elusive. This review synthesizes current literature on FWE-mediated membrane trafficking, highlighting the evolutionary conservation of its coding sequence and tertiary structure. We propose new structure-compatible hypotheses for FWE-dependent cytosolic Ca[2+] elevation and subsequent ELRO trafficking, highlighting experimental strategies that may aid testing of these hypotheses. Finally, we examine the distinct localizations and potential functions of non-canonical FWE isoforms.

Single-stranded DNA (ssDNA) is an emerging nucleic acid tool with the potential to become a more efficient genetic delivery vector than traditional plasmids in prokaryotes. While conventional double-stranded DNA (dsDNA) vectors are easily recognized and attacked by bacterial defense systems, ssDNA's structural differences make it resistant to corresponding enzymatic recognition. Moreover, the presence of unpaired bases in ssDNA enables efficient binding with other molecules, allowing for regulated gene expression and targeted delivery of other nucleic acids or molecules. In this study, we investigated the natural forms of ssDNA and summarized its synthesis and introduction methods. By analyzing existing applications of ssDNA in eukaryotes, we demonstrated the strategies and advantages of applying it to genetic manipulation in prokaryotes.

A chloroplast is a subcellular organelle of photosynthesis in plant and algal cells. A chloroplast's genome encodes proteins of the photosynthetic electron transport chain along with proteins required to express them. Chloroplast-encoded photosynthetic proteins function in close contact with proteins whose precursors are encoded in the cell nucleus for cytosolic synthesis, import into the chloroplast, and subsequent processing. Protein complexes of photosynthetic electron transport thus contain polypeptides with one of two quite different sites of synthesis. Most chloroplast proteins are products of nuclear genes. Why not all? One proposal is that photosynthetic electron transport governs expression of genes for its own components: co-location of chloroplast genes with their gene products allows redox regulation of gene expression in individual organelles. Recent advances indicate that redox regulation impacts all stages of chloroplast gene expression. Here I propose that components of this regulation physically tether chloroplast DNA to the thylakoid membrane.

Recent work has expanded understanding of extracellular vesicle (EV) biology by identifying midbody remnants (MBRs) as large, translationally competent vesicles released during mitosis. MBRs contain ribosomes, mitochondria, translation factors, and selected mRNAs and small RNAs concentrated within a condensate‑like ribonucleoprotein core and can support protein synthesis after extracellular release. These features distinguish MBRs from more extensively studied exosomes and microvesicles yet also place them within a broader continuum of large EVs with organelle‑rich, cell‑like properties. This review summarizes current knowledge of MBR biogenesis, molecular organization, and translation competency; contrasts MBRs with canonical EVs and other large EVs; and discusses possible roles in development, tissue homeostasis, disease, and brain function. Particular emphasis is placed on outstanding mechanistic and physiological questions, including how MBR translation is regulated, which recipient cells interact with endogenous MBRs, and whether translation‑competent EVs offer practical advantages over existing EV platforms for therapeutic or biotechnological applications.

Prostanoids are involved in various physiological/pathophysiological functions, such as inflammation. Since persistent inflammation may cause chronic symptoms, their activation is very short and needs to be properly terminated. Due to structural similarities, some prostanoids and their metabolites may have ability to activate noncognate prostanoid receptors as biased agonists and/or blockers. However, the physiological roles of these biased activities remain unclear. This review mainly focused on prostaglandin (PG) E2 and PGD2 as well as their metabolites, and hypothesized that the physiological roles of their biased activities may be novel nongenomic immediate feedback systems strictly confined to local areas as autacoids. These nongenomic feedback systems completely differ from the genomic feedback systems used by endocrine hormones. Therefore, the biased activities of prostanoids may be newly defined and/or re-acknowledged as unique, rapid, and fine-tuned translation/transcription-free feedback systems which may be responsible for the roles of prostanoids in maintaining homeostasis as rapid-acting local-mediators, autacoids.

Regulatory T cells (Tregs) are central to immune tolerance, yet antigen-specific cell therapies lag behind cytotoxic CAR-T approaches. Most CAR-Treg programs still use single-chain variable fragments (scFvs) derived from monoclonal antibodies optimized for effector function, a bias that may promote CAR clustering, tonic signaling, and lineage instability. Here, we propose a phage-first binder discovery framework for CAR-Tregs and state testable hypotheses linking phage-display selection pressures to scFv biophysical properties and Treg fate. We hypothesize that multi-parameter selection and counter-selection can enrich scFvs with moderate affinity, low polyspecificity, and improved framework stability, thereby lowering tonic signaling in defined backbone architectures and preserving FOXP3/TSDR stability under inflammatory stress. We outline a falsifiable two-phase roadmap-bench triage followed by mechanistic and preclinical validation to determine how scFv properties, expression level, and intracellular signaling domains define an optimal tonic window for durable immune regulation.

In eukaryotes, DNA is not a naked repository of genetic information but is tightly wound around histone octamers to form nucleosomes. While this packaging solves the spatial problem of fitting 2 meters of DNA into a microscopic nucleus, it creates a massive accessibility problem for DNA-templated events, including transcription, replication, and DNA repair. Here, we review how the chromodomain helicase DNA-binding (CHD) family of ATP-dependent nucleosome remodelers act as the molecular acrobats of the chromatin accessibility landscape. We highlight that the three CHD subfamilies represent a developmental division of labor: subfamily I maintains pluripotent chromatin accessibility, subfamily II drives lineage commitment through chromatin closure, and subfamily III establishes tissue-specific enhancer and promoter accessibility during organogenesis. By dynamically transforming chromatin architecture through nucleosome sliding, spacing, and ejection, CHD remodelers license the transitions between cell states, ensuring that the epigenetic landscape is reshaped for the specific needs of a stem cell today and a differentiated cell type tomorrow. We discuss how disruption of this licensing, through mutation or loss of family members, leads to severe neurodevelopmental disorders, including CHARGE syndrome, autism spectrum disorder, and intellectual disability. We close by raising outstanding questions including how CHD activity is regulated, how co-expressed paralogs coordinate their activities, and whether CHD dysfunction can be therapeutically targeted.

PH domain leucine-rich repeat protein phosphatases 1 and 2 (PHLPP1/PHLPP2) have, for more than 20 years, been described as Akt phosphatases and tumor suppressor genes. Approximately 200 PubMed-indexed articles have been published on the topic, including efforts to pharmacologically inhibit PHLPP in disease settings. A recent study, however, presents evidence that PHLPP is actually a pseudophosphatase with no catalytic activity. These observations question its reported role in cancer. The designation of PHLPP1 and PHLPP2 as pseudophosphatases necessitates both a critical examination of the literature and new hypotheses for the biological function of these ancient proteins. Here, we review the emergence of PHLPP1 and PHLPP2 as cellular signal transducers, critically examine the evidence for their reported phosphatase activity and tumor suppressor functions, and propose steps to elucidate their biological functions.

In a 2018 paper and a subsequent article published in 2023, researchers reported that mitochondria maintain temperatures 10°C-15°C higher than the surrounding cytoplasm-a finding that deviates by five to six orders of magnitude from theoretical predictions based on Fourier's law of heat conduction. In 2022, we proposed a solution to this apparent paradox. In the present perspective, we build upon that framework and introduce new ideas to further unravel how a biological membrane-whether of an organelle or a whole cell-can become significantly warmer than its environment. We propose that ion-translocating proteins embedded in the inner mitochondrial membrane (IMM) can be modeled as ratchet engines, introducing a novel, previously overlooked mode of heat transfer. This mechanism, coupled with localized heat release during the cyclical dehydration-translocation-hydration of ions through membrane proteins, may generate transient but substantial temperature spikes. The cumulative thermal occupancy of these microscopic events across the three-dimensional surface of the IMM can account for the elevated temperatures detected by molecular probes.

Human cooperation is often explained through motivations and values, but it is also a strategic and evolutionary problem: locally advantageous behavior can erode the collective arrangements on which everyone depends. Dawkins' gene-centered view remains useful here, not as a moral theory of selfish people, but as a way to track how lower-level selection can destabilize higher-level organization. I argue, however, that cooperation is stabilized by a broader repertoire than external punishment alone. Repeated interaction, partner choice, aligned incentives, and architectural constraints can all make cheating unattractive; in many settings, additional suppressors then make defection costly or unprofitable. On this view, game theory and a multilevel evolutionary lens are complementary. The Folk Theorem shows how cooperative outcomes can be sustained endogenously under patience and monitoring, while biology shows how the informational and structural conditions for such equilibria are themselves produced or maintained. The point is diagnostic rather than fatalistic: cooperation is typically conditional, costly to sustain, and shaped by trade-offs, but humans can redesign incentives and institutions, especially in digital environments where misinformation and attention now propagate with unusual speed and fidelity.