Most superconducting materials are well understood and conventional-that is, the pairs of electrons that cause the superconductivity by their condensation have the highest possible symmetry. Famous exceptions are the enigmatic high-temperature (high-Tc) cuprate superconductors1. Nodes in their superconducting gap are the fingerprint of their unconventional character and imply superconducting pairing of d-wave symmetry. Here, by using angle-resolved photoemission spectroscopy, we observe that the Weyl semimetal PtBi2 harbours nodes in its superconducting gap, implying unconventional i-wave pairing symmetry. At temperatures below 10 K, the superconductivity in PtBi2 gaps out its topological surface states, the Fermi arcs, whereas its bulk states remain normal2. The nodes in the superconducting gap that we observe are located exactly at the centre of the Fermi arcs and imply the presence of topologically protected Majorana cones around this locus in momentum space. From this, we infer theoretically that robust zero-energy Majorana flat bands emerge at surface step edges. This establishes PtBi2 surfaces not only as unconventional, topological i-wave superconductors but also as a promising material platform in the ongoing effort to generate and manipulate Majorana bound states.

Insulating nanomaterials have large energy gaps and are only electrically accessible under extreme conditions, such as high-intensity radiation and high temperature, pressure or voltage1,2. Lanthanide-doped insulating nanoparticles (LnNPs) are widely studied owing to their exceptional luminescence properties, including bright, narrow-linewidth, non-blinking and non-bleaching emission in the second near-infrared (NIR-II) range3,4. However, it has not been possible to electrically generate excited states in these insulating nanomaterials under low biases and, therefore, not possible to fabricate optoelectronic devices from these systems. Here we report an electrical excitation pathway to obtain emission from LnNPs. By forming LnNP@organic molecule nanohybrids, in which the recombination of electrically injected charges on the organic molecule is followed by efficient triplet energy transfer (TET) to the LnNP, it is possible to turn on LnNPs under a low operating bias. We demonstrate this excitation pathway in light-emitting diodes (LEDs), with low turn-on voltages of about 5 V, very narrow electroluminescence (EL) spectra and a peak external quantum efficiency (EQE) greater than 0.6% in the NIR-II window5. Our LnNP-based LEDs (LnLEDs) also allow for widely tunable EL properties, by changing the type and concentration of lanthanide dopants. These results open up a new field of hybrid optoelectronic devices and provide new opportunities for the electrically driven excitation sources based on lanthanide nanomaterials for biomedical and optoelectronic applications.

Lanthanide nanocrystals offer unique advantages for electroluminescence (EL) applications, including narrow-band emission, high colour purity and compositionally tunable output1-4. However, their insulating nature poses a challenge for carrier transport and injection, impeding their application in electrically driven optoelectronic devices5. Here we demonstrate efficient EL from insulating lanthanide fluoride nanocrystals (4 nm; NaGdF4:X; X = Tb3+, Eu3+ or Nd3+) coated with a series of functionalized 2-(diphenylphosphoryl)benzoic acids (ArPPOA). These ligands, featuring donor-phosphine oxide acceptor hybrids with carboxyl and P=O coordination sites, effectively sensitize the luminescence of lanthanide nanocrystals by modulating the intraligand charge transfer characteristics. Ultrafast spectroscopic investigations reveal that strong coupling between ArPPOA and lanthanide nanocrystals facilitates intersystem crossing (ISC; <1 ns) and highly efficient triplet energy transfer to nanocrystals (up to 96.7%). Through careful control of dopant composition and concentration in nanocrystals, we also achieve wide-ranging multicolour EL without altering the device architecture, reaching an external quantum efficiency exceeding 5.9% for Tb3+. This ligand-functionalized nanocrystal platform provides a modular strategy for exciton control in insulating nanocrystal systems, offering a pathway for spectrally precise electroluminescent materials.

Flexible control of motor timing is crucial for behaviour1-4. Before volitional movement begins, the frontal cortex and striatum exhibit ramping spiking activity, with variable ramp slopes anticipating movement onsets5-12. This activity in the cortico-basal ganglia loop may function as an adjustable 'timer,' triggering actions at the desired timing. However, because the frontal cortex and striatum share similar ramping dynamics and are both necessary for timing behaviours, distinguishing their individual roles in this timer function remains challenging. Here, to address this, we conducted perturbation experiments combined with multi-regional electrophysiology in mice performing a flexible lick-timing task. Following transient silencing of the frontal cortex, cortical and striatal activity swiftly returned to pre-silencing levels and resumed ramping, leading to a shift in lick timing close to the silencing duration. Conversely, briefly inhibiting the striatum caused a gradual decrease in ramping activity in both regions, with ramping resuming from post-inhibition levels, shifting lick timing beyond the inhibition duration. Thus, inhibiting the frontal cortex and striatum effectively paused and rewound the timer, respectively. These findings are consistent with a model in which the striatum is part of a network that temporally integrates input from the frontal cortex and generates ramping activity that regulates motor timing.

Ribosome collisions activate the ribotoxic stress response mediated by the MAP3K ZAK, which in turn regulates cell-fate consequences through downstream phosphorylation of the MAPKs p38 and JNK1. Despite the critical role of ZAK during cellular stress, a mechanistic and structural understanding of ZAK-ribosome interactions and how these lead to activation remain elusive. Here we combine biochemistry and cryo-electron microscopy to discover distinct ZAK-ribosome interactions required for constitutive recruitment and for activation. We find that upon induction of ribosome collisions, interactions between ZAK and the ribosomal protein RACK1 enable its activation by dimerization of its SAM domains at the collision interface. Furthermore, we discover how this process is negatively regulated by the ribosome-binding protein SERBP1 to prevent constitutive ZAK activation. Characterization of novel SAM variants as well as a known pathogenic variant of the SAM domain of ZAK supports a key role of the SAM domain in regulating kinase activity on and off the ribosome, with some mutants bypassing the ribosome requirement for ZAK activation. Collectively, our data provide a mechanistic blueprint of the kinase activity of ZAK at the collided ribosome interface.

Emerging evidence suggests a correlation between CD8+ T cell-tumour cell proximity and anti-tumour immune response1,2. However, it remains unclear whether these cells exist as functional clusters that can be isolated from clinical samples. Here, using conventional and imaging flow cytometry, we show that from 21 out of 21 human melanoma metastases, we could isolate heterotypic clusters, comprising CD8+ T cells interacting with one or more tumour cells and/or antigen-presenting cells (APCs). Single-cell RNA-sequencing analysis revealed that T cells from clusters were enriched for gene signatures associated with tumour reactivity and exhaustion. Clustered T cells exhibited increased TCR clonality indicative of expansion, whereas TCR-matched T cells showed more exhaustion and co-modulation when conjugated to APCs than when conjugated to tumour cells. T cells that were expanded from clusters ex vivo exerted on average ninefold increased killing activity towards autologous melanomas, which was accompanied by enhanced cytokine production. After adoptive cell transfer into mice, T cells from clusters showed improved patient-derived melanoma control, which was associated with increased T cell infiltration and activation. Together, these results demonstrate that tumour-reactive CD8+ T cells are enriched in functional clusters with tumour cells and/or APCs and that they can be isolated and expanded from clinical samples. Typically excluded by single-cell gating in flow cytometry, these distinct heterotypic T cell clusters are a valuable source to decipher functional tumour-immune cell interactions and may also be therapeutically explored.

Most molecules of chemistry and biology are chiral, leading to mirror image variants, so called enantiomers. However, while the selective chemical synthesis of molecules where the stereogenicity arises from a carbon atom is well-established, enantioselective approaches to nitrogen-stereogenic molecules are much less common,1-3 and in case of acyclic, N-stereogenic amines, even elusive, due to their rapid pyramidal inversion. We describe here the catalytic asymmetric synthesis of stable, acyclic N-stereogenic amines by the addition of enol silanes to nitronium ions that ion pair to a confined chiral anion. In the produced so-called anomeric amines, the commonly observed isomerization is slowed down by two N-oxy-substituents, which hamper nitrogen inversion. The critical stereogenicity creating step challenges previously established stereochemical descriptors of enantiodifferentiation. Computational studies provide additional insight into the origin of the observed stereocontrol. Our work opens up a new avenue to investigate the fascinating and previously underexplored chemistry of enantiopure anomeric amines.

All spoken languages are produced by the human vocal tract, which defines the limited set of possible speech sounds. Despite this constraint, however, there exists incredible diversity in the world's 7,000 spoken languages, each of which is learned through extensive experience hearing speech in language-specific contexts1. It remains unknown which elements of speech processing in the brain depend on daily language experience and which do not. In this study, we recorded high-density cortical activity from adult participants with diverse language backgrounds as they listened to speech in their native language and an unfamiliar foreign language. We found that, regardless of language experience, both native and foreign languages elicited similar cortical responses in the superior temporal gyrus (STG), associated with shared acoustic-phonetic processing of foundational speech sound features2,3, such as vowels and consonants. However, only during native language listening did we observe enhanced neural encoding in the STG for word boundaries, word frequency and language-specific sound sequence statistics. In a separate cohort of bilingual participants, this encoding of word- and sequence-level information appeared for both familiar languages in the same individual and in the same STG neural populations. These results indicate that experience-dependent language processing involves dynamic integration of both shared acoustic-phonetic and language-specific sequence- and word-level information in the STG.

Generative genomic models can design increasingly complex biological systems1. However, controlling these models to generate novel sequences with desired functions remains challenging. Here, we show that Evo, a genomic language model, can leverage genomic context to perform function-guided design that accesses novel regions of sequence space. By learning semantic relationships across prokaryotic genes2, Evo enables a genomic 'autocomplete' in which a DNA prompt encoding genomic context for a function of interest guides the generation of novel sequences enriched for related functions, which we refer to as 'semantic design'. We validate this approach by experimentally testing the activity of generated anti-CRISPR proteins and type II and III toxin-antitoxin systems, including de novo genes with no significant sequence similarity to natural proteins. In-context design of proteins and non-coding RNAs with Evo achieves robust activity and high experimental success rates even in the absence of structural priors, known evolutionary conservation or task-specific fine-tuning. We then use Evo to complete millions of prompts to produce SynGenome, a database containing over 120 billion base pairs of artificial intelligence-generated genomic sequences that enables semantic design across many functions. More broadly, these results demonstrate that generative genomics with biological language models can extend beyond natural sequences.

Precise genome-editing technologies such as base editing1,2 and prime editing3 can correct most pathogenic gene variants, but their widespread clinical application is impeded by the need to develop new therapeutic agents for each mutation. For diseases that are caused by premature stop codons, suppressor tRNAs (sup-tRNAs) offer a more general strategy. Existing approaches to use sup-tRNAs therapeutically, however, require lifelong administration4,5 or show modest potency, necessitating potentially toxic overexpression. Here we present prime editing-mediated readthrough of premature termination codons (PERT), a strategy to rescue nonsense mutations in a disease-agnostic manner by using prime editing to permanently convert a dispensable endogenous tRNA into an optimized sup-tRNA. Iterative screening of thousands of variants of all 418 human tRNAs identified tRNAs with the strongest sup-tRNA potential. We optimized prime editing agents to install an engineered sup-tRNA at a single genomic locus without overexpression and observed efficient readthrough of premature termination codons and protein rescue in human cell models of Batten disease, Tay-Sachs disease and cystic fibrosis. In vivo delivery of a single prime editor that converts an endogenous mouse tRNA into a sup-tRNA extensively rescued disease pathology in a model of Hurler syndrome. PERT did not induce detected readthrough of natural stop codons or cause significant transcriptomic or proteomic changes. Our findings suggest the potential of disease-agnostic therapeutic genome-editing approaches that require only a single composition of matter to treat diverse genetic diseases.

Neurons exhibit extraordinary precision in selecting synaptic partners. Although cell-surface proteins (CSPs) that mediate attractive interactions between developing axons and dendrites have been shown to instruct synaptic partner matching1,2, the degree to which repulsive interactions have a role is less clear. Here, using a genetic screen guided by single-cell transcriptomes3,4, we identified three CSP pairs, Toll2-Ptp10D, Fili-Kek1 and Hbs/Sns-Kirre, that mediate repulsive interactions between non-partner olfactory receptor neuron (ORN) axons and projection neuron (PN) dendrites in the developing Drosophila olfactory circuit. Each CSP pair exhibits inverse expression patterns in the select ORN-PN partners. Loss of each CSP in ORNs led to similar synaptic partner matching deficits as the loss of its partner CSP in PNs, and mistargeting phenotypes caused by overexpressing one CSP could be suppressed by loss of its partner CSP. All CSP pairs are also differentially expressed in other brain regions. Together, our data reveal that multiple repulsive CSP pairs work together to ensure precise synaptic partner matching during development by preventing neurons from forming connections with non-cognate partners.

Oncogenic mutations in phenotypically normal tissue are common across adult organs1,2. This suggests that multiple events need to converge to drive tumorigenesis and that many processes such as tissue differentiation may protect against carcinogenesis. WNT-β-catenin signalling maintains zonal differentiation during liver homeostasis3,4. However, the CTNNB1 oncogene-encoding β-catenin-is also frequently mutated in hepatocellular carcinoma, resulting in aberrant WNT signalling that promotes cell growth5,6. Here we investigated the antagonistic interplay between WNT-driven growth and differentiation in zonal hepatocyte populations during liver tumorigenesis. We found that β-catenin mutations co-operate with exogenous MYC expression to drive a proliferative translatome. Differentiation of hepatocytes to an extreme zone 3 fate suppressed this proliferative translatome. Furthermore, a GLUL and Lgr5-positive perivenous subpopulation of zone 3 hepatocytes were refractory to WNT-induced and MYC-induced tumorigenesis. However, when mutant CTNNB1 and MYC alleles were activated sporadically across the liver lobule, a subset of mutant hepatocytes became proliferative and tumorigenic. These early lesions were characterized by reduced WNT pathway activation and elevated MAPK signalling, which suppresses zone 3 differentiation. The proliferative lesions were also dependent on IGFBP2-mTOR-cyclin D1 pathway signalling, in which inhibition of either IGFBP2 or mTOR suppressed proliferation and tumorigenesis. Therefore, we propose that zonal identity dictates hepatocyte susceptibility to WNT-driven tumorigenesis and that escaping WNT-induced differentiation is essential for liver cancer.

Proper brain function requires the precise assembly of neural circuits during development. Despite the identification of many cell-surface proteins (CSPs) that help guide axons to their targets1,2, it remains mostly unknown how multiple CSPs work together to assemble a functional circuit. Here we used synaptic partner matching in the Drosophila olfactory circuit3,4 to address this question. By systematically altering the combination of differentially expressed CSPs in a single type of olfactory receptor neuron (ORN), which senses a male pheromone that inhibits male-male courtship, we switched its connection nearly completely from its endogenous postsynaptic projection neuron (PN) type to a new PN type that promotes courtship. From this switch, we deduced a combinatorial code including CSPs that mediate both attraction between synaptic partners and repulsion between non-partners5,6. The anatomical switch changed the odour response of the new PN partner and markedly increased male-male courtship. We generalized three manipulation strategies from this rewiring-increasing repulsion with the old partner, decreasing repulsion with the new partner and matching attraction with the new partner-to successfully rewire a second ORN type to multiple distinct PN types. This work shows that manipulating a small set of CSPs is sufficient to respecify synaptic connections, paving the way to investigations of how neural systems evolve through changes of circuit connectivity.

Neural representations of information are shaped by long-range input and local network interactions. Previous studies linking neural coding and cortical connectivity have focused on input-driven activity in the sensory cortex1-3. Here we studied neural activity in the motor cortex while mice gathered rewards with multidirectional tongue reaching. This behaviour does not require training, allowing us to probe neural coding and connectivity before activity is shaped by extended learning. Motor cortex neurons were tuned to target location and reward outcome, and typically responded during and after movements. We studied the underlying network interactions in vivo by estimating causal neural connections using an all-optical method3-6. Mapping connectivity between more than 20,000,000 excitatory neuron pairs showed a multi-scale columnar architecture in layer 2/3 of the motor cortex. Neurons displayed local (less than 100 µm) like-to-like excitatory connectivity according to target-location tuning, and inhibition over longer spatial scales. Connectivity patterns comprised a continuum, with abundant sparsely connected neurons and rare densely connected neurons that function as network hubs. Hub neurons were weakly tuned to target location and reward outcome but influenced more neighbouring neurons. This network of neurons, encoding location and outcome of movements to different motor goals, may be a general substrate for rapid learning of complex, goal-directed behaviours.

Most human secretory pathway proteins are N-glycosylated by oligosaccharyltransferase (OST) complexes as they enter the endoplasmic reticulum (ER)1-3. Recent work revealed a substrate-assisted mechanism by which N-glycosylation of the chaperone glucose-regulated protein 94 (GRP94) is regulated to control cell surface receptor signalling4. Here we report the structure of a natively isolated GRP94 folding intermediate tethered to a specialized CCDC134-bound translocon. Together with functional analysis, the data reveal how a conserved N-terminal extension in GRP94 inhibits OST-A and how structural rearrangements within the translocon shield the tethered nascent chain from inappropriate OST-B glycosylation. These interactions depend on a hydrophobic CCDC134 groove, which recognizes a non-native conformation of nascent GRP94. Our results define a mechanism of regulated N-glycosylation and illustrate how the nascent chain remodels the translocon to facilitate its own biogenesis.

Non-invasive skin permeation is widely used for convenient transdermal delivery of small-molecule therapeutics (less than 500 Da) with appropriate hydrophobicities1. However, it has long been deemed infeasible for large molecules-particularly polymers, proteins and peptides2,3-due to the formidable barrier posed by the skin structure. Here we show that the fast skin-permeable polyzwitterion poly[2-(N-oxide-N,N-dimethylamino)ethyl methacrylate] (OP) can efficiently penetrate the stratum corneum, viable epidermis and dermis into circulation. OP is protonated to be cationic and is therefore enriched in the acidic sebum and paracellular stratum corneum lipids containing fatty acids, and subsequently diffuses through the intercorneocyte lipid lamella. Beneath the stratum corneum, at the normal physiological pH, OP becomes a neutral polyzwitterion, 'hopping' on cell membranes, enabling its efficient migration through the epidermis and dermis and ultimately entering dermal lymphatic vessels and systemic circulation. As a result, OP-conjugated insulin efficiently permeates through the skin into the blood circulation; transdermal administration of OP-conjugated insulin at a dose of 116 U kg-1 into mice with type 1 diabetes quickly lowers their blood glucose levels to the normal range, and a transdermal dose of 29 U kg-1 normalizes the blood glucose levels of diabetic minipigs. Thus, the skin-permeable polymer may enable non-invasive transdermal delivery of insulin, relieving patients with diabetes from subcutaneous injections and potentially facilitating patient-friendly use of other protein- and peptide-based therapeutics through transdermal delivery.

Extrachromosomal DNA (ecDNA) is a prevalent and devastating form of oncogene amplification in cancer1,2. Circular megabase-sized ecDNAs lack centromeres, stochastically segregate during cell division3-6 and persist over many generations. It has been more than 40 years since ecDNAs were first observed to hitchhike on mitotic chromosomes into daughter cell nuclei, but the mechanism underlying this process remains unclear3,7. Here we identify a family of human genomic elements, termed retention elements, that tether episomes to mitotic chromosomes to increase ecDNA transmission to daughter cells. Using Retain-seq, a genome-scale assay that we developed, we reveal thousands of human retention elements that confer generational persistence to heterologous episomes. Retention elements comprise a select set of CpG-rich gene promoters and act additively. Live-cell imaging and chromosome conformation capture show that retention elements physically interact with mitotic chromosomes at regions that are mitotically bookmarked by transcription factors and chromatin proteins. This activity intermolecularly recapitulates promoter-enhancer interactions. Multiple retention elements are co-amplified with oncogenes on individual ecDNAs in human cancers and shape their sizes and structures. CpG-rich retention elements are focally hypomethylated. Targeted cytosine methylation abrogates retention activity and leads to ecDNA loss, which suggests that methylation-sensitive interactions modulate episomal DNA retention. These results highlight the DNA elements and regulatory logic of mitotic ecDNA retention. Amplifications of retention elements promote the maintenance of oncogenic ecDNA across generations of cancer cells, and reveal the principles of episome immortality intrinsic to the human genome.

During the past decade, our understanding of eukaryotic evolution has increased immensely. Newly recognized eukaryotic supergroups have been established1-3, and most enigmatic orphan lineages have had their relationships resolved4-6. Studies on unicellular protist eukaryotes have also been key to understanding the evolution of mitochondria, the fundamental organelles of the eukaryotic cell, which originated from an alphaproteobacterial ancestor. The retention of ancestral alphaproteobacterial pathways in some protist lineages reveals that the mitochondrion of the last eukaryotic common ancestor was more metabolically versatile than are the highly derived mitochondria that are found in most modern eukaryotes7,8. Here we report the discovery of such a unicellular eukaryote, Solarion arienae gen. et sp. nov., an inconspicuous, free-living heterotrophic protist with two morphologically distinct cell types and a novel type of predatory extrusome. We assign Solarion to the new phylum Caelestes. Together with Provora, hemimastigophoreans and Meteora, they form a new eukaryotic supergroup, Disparia. Moreover, S. arienae has some noteworthy traits associated with the mitochondrial genome; in particular, the mitochondrially encoded secA gene, a remnant of an ancestral alphaproteobacterial protein secretion pathway, which has been lost almost entirely in extant mitochondria9,10. The discovery of S. arienae broadens our understanding of early eukaryotic evolution and facilitates the study of proto-mitochondrial metabolic remnants, shedding light on the complexity of ancestral eukaryotic life.

Organ shortage remains a major challenge in transplantation, and gene-edited pig organs offer a promising solution1-3. Despite gene-editing, the immune reactions following xenotransplantation can still cause transplant failure4. To understand the immunological response of a pig-to-human kidney xenotransplantation, we conducted large-scale multi-omics profiling of the xenograft and the host's blood over a 61-day procedure in a brain-dead human (decedent) recipient. Blood plasmablasts, natural killer (NK) cells, and dendritic cells increased between postoperative day (POD)10 and 28, concordant with expansion of IgG/IgA B-cell clonotypes, and subsequent biopsy-confirmed antibody-mediated rejection (AbMR) at POD33. Human T-cell frequencies increased from POD21 and peaked between POD33-49 in the blood and xenograft, coinciding with T-cell receptor diversification, expansion of a restricted TRBV2/J1 clonotype and histological evidence of a combined AbMR and cell-mediated rejection at POD49. At POD33, the most abundant human immune population in the graft was CXCL9+ macrophages, aligning with IFN-γ-driven inflammation and a Type I immune response. In addition, we see evidence of interactions between activated pig-resident macrophages and infiltrating human immune cells. Xenograft tissue showed pro-fibrotic tubular and interstitial injury, marked by S100A65, SPP16 (Osteopontin), and COLEC117, at POD21-POD33. Proteomics profiling revealed human and pig complement activation, with decreased human component after AbMR therapy with complement inhibition. Collectively, these data delineate the molecular orchestration of human immune responses to a porcine kidney, revealing potential immunomodulatory targets for improving xenograft survival.

Xenotransplantation of genetically-modified pig kidneys offers a solution to the scarcity of organs for end-stage renal disease patients.1 We performed a 61-day alpha-Gal knock-out pig kidney and thymic autograft transplant into a nephrectomized brain-dead human using clinically approved immunosuppression, without CD40 blockade or additional genetic modification. Hemodynamic and electrolyte stability and dialysis independence were achieved. Post-operative day (POD) 10 biopsies revealed glomerular IgM and IgA deposition, activation of early complement components and mesangiolysis with stable renal function without proteinuria, a phenotype not seen in allotransplantation. On POD 33, an abrupt increase in serum creatinine was associated with antibody-mediated rejection and increased donor-specific IgG. Plasma exchange, C3/C3b inhibition and rabbit anti-thymocyte globulin (rATG), completely reversed xenograft rejection. Pre-existing donor-reactive T cell clones expanded progressively in the circulation post-transplant, acquired an effector transcriptional profile and were detected in the POD 33 rejecting xenograft prior to rATG treatment. This study provides the first long-term physiologic, immunologic, and infectious disease monitoring of a pig-to-human kidney xenotransplant and indicates that pre-existing xenoreactive T cells and induced antibodies to unknown epitope(s) present a major challenge, despite significant immunosuppression. It also demonstrates that a minimally gene-edited pig kidney can support long-term life-sustaining physiologic functions in a human.