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Wright, D. J.

Publications and source records attributed to Wright, D. J..

7 recordsLinked to original sources

Single-nucleus profiling of social behaviour in a mutualistic reef fish

Complex social decision-making in vertebrates relies on a conserved network within the forebrain. However, the precise neural cell populations and gene regulatory networks that orchestrate these sophisticated social behaviours remain largely unresolved. Here, we present the first single-nucleus transcriptome atlas of the telencephalon in the cleaner wrasse Labroides dimidiatus, a remarkable model for advanced social cognition. Profiling ~67,000 telencephalic nuclei, we mapped the neural architecture of the teleost forebrain and identified highly conserved cell populations including a cholinergic-GABAergic neuron population implicated in social behaviours and cells resembling mammalian striatal medium spiny neurons and hippocampal cell types. By comparing distinct behavioural states, we found that socially interacting fish expanded radial glial subclusters, and associative learning co-expression networks, whereas social observers exhibited gene expression signatures for motivation and behavioural preparedness. Ultimately, the resolved telencephalon atlas reveals the evolutionarily conserved cellular and molecular substrates that may govern complex social behaviour across vertebrates.

animal behavior and cognition↗

ZNFX1 uses two-component ubiquitin circuitry to quarantine viral RNA

The detection of viral RNA inside cells triggers a diverse range of antiviral responses, including global translation inhibition, interferon secretion and RNA sequestration. Mutations in the gene ZNFX1 cause severe paediatric immunodeficiencies, including chronic viral infection and autoinflammation. Here, we show that ZNFX1 is an RNA helicase with cryptic and unusual bifurcating E3 ubiquitin ligase activity. Nucleotide-dependent RNA binding stimulates ZNFX1 to generate complex ubiquitin chains via a two-component ubiquitin circuit wired in parallel, with ubiquitin flux occurring via either of two competing paths. One route produces K63-linked polyubiquitin that drives ZNFX1 aggregation and RNA entrapment; the other route produces K48-linked polyubiquitin that drives ZNFX1 turnover. RNA entrapment restricts RNA virus replication, and is reversible by deubiquitination. Patient ZNFX1 variants are defective for viral restriction, linking RNA entrapment to antiviral immunity in vivo.

biochemistry↗

A comparison of long-read single-cell transcriptomic approaches

Long-read sequencing enables the incorporation of isoform-level expression into single-cell transcriptomic studies, offering detail beyond those accessible with short-read methods. Although insightful, these approaches have typically been costly and yielded limited data for each individual cell. Recent advances in library preparation approaches and sequencing throughput have brought long-read single-cell studies closer to the mainstream. Here, we present a comparative analysis of commercial approaches for single-cell long-read sequencing. We have performed parallel analyses of the same cDNA material, generated using the 10X genomics platform, on Illumina short-read, and PacBio and Oxford Nanopore long-read platforms. We also demonstrate the impact of CRISPR-based depletion of libraries, to remove highly expressed transcripts, prior to long-read sequencing in these experiments. By analysing single-source cDNA libraries in parallel, we enable a direct comparison of each platform, evaluating standard metrics alongside concordance in clustering and cell type identification. While each approach generates usable gene and isoform expression data, we identify limitations common across platforms, primarily linked to cDNA synthesis inefficiencies and read filtering strategies. Our work demonstrates the increasing utility of single-cell long-read sequencing for isoform-resolved analyses, such as direct immunoglobulin chain reconstruction without additional amplification, and the detection of alternative splicing patterns across immune cell subtypes in CD45, a key gene for immune cell activation and differentiation. Our benchmarking of current platform options provides a foundation for researchers looking to adopt single-cell long-read sequencing into their transcriptomic studies, providing a framework for its integration into diverse biological questions.

cell biology↗

The effects of combined action observation and motor imagery on corticospinal excitability and movement outcomes: A meta-analysis

Motor simulation interventions involving motor imagery (MI) and action observation (AO) have received considerable interest in the behavioral sciences. A growing body of research has focused on using AO and MI simultaneously, termed combined action observation and motor imagery (AOMI). The current paper includes two meta-analyses that quantify changes in corticospinal excitability and motor skill performance for AOMI compared to AO, MI and control conditions. Specifically, the first meta-analysis collated and synthesized existing motor evoked potential (MEP) amplitude data from transcranial magnetic stimulation studies and the second meta-analysis collated and synthesized existing movement outcome data from behavioral studies. AOMI had a positive effect compared to control and AO but not MI conditions for both MEP amplitudes and movement outcomes. No methodological factors moderated the effects of AOMI, indicating a robust effect of AOMI across the two outcome variables. The results of the meta-analyses are discussed in relation to existing literature on motor simulation and skill acquisition, before providing viable directions for future research on this topic. HighlightsO_LIMotor imagery (MI) and action observation (AO) can be combined (AOMI) C_LIO_LIThis paper synthesizes neurophysiological and behavioral evidence for AOMI C_LIO_LIAOMI had increased corticospinal excitability compared to AO and control but not MI C_LIO_LIAOMI led to improved movement outcomes compared to AO and control but not MI C_LIO_LIThe reported effects of AOMI were maintained across all moderators C_LI

neuroscience↗

Long read sequencing reveals novel isoforms and insights into splicing regulation during cell state changes

Alternative splicing (AS) is a key mechanism underlying cellular differentiation and a driver of complexity in mammalian neuronal tissues. However, understanding of which isoforms are differentially used or expressed and how this affects cellular differentiation remains unclear. Long read sequencing allows full-length transcript recovery and quantification, enabling transcript-level analysis of AS processes and how these change with cell state. Here, we utilise Oxford Nanopore Technologies sequencing to produce a custom annotation of a well-studied human neuroblastoma cell line and to characterise isoform expression and usage across differentiation. We identify many previously unannotated features, including a novel transcript of the voltage-gated calcium channel subunit gene, CACNA2D2. We show differential expression and usage of transcripts during differentiation, and identify a putative molecular regulator underlying this state change. Our work highlights the potential of long read sequencing to uncover previously unknown transcript diversity and mechanisms influencing alternative splicing.

genomics↗

Need for speed: Examining protein behaviour during cryoEM grid preparation at different timescales

A host of new technologies are under development to improve the quality and reproducibility of cryoEM grid preparation. Here we have systematically investigated the preparation of three macromolecular complexes using three different vitrification devices (Vitrobot, chameleon and a time-resolved cryoEM device) on various timescales, including grids made within 6 ms, (the fastest reported to date), to interrogate particle behaviour at the air-water interface for different timepoints. Results demonstrate that different macromolecular complexes can respond to the thin film environment formed during cryoEM sample preparation in highly variable ways, shedding light on why cryoEM sample preparation can be difficult to optimise. We demonstrate that reducing time between sample application and vitrification is just one tool to improve cryoEM grid quality, but that it is unlikely to be a generic silver bullet for improving the quality of every cryoEM sample preparation.

biochemistry↗

Cryo-EM structures of human TRPC5 reveal interaction of a xanthine-based TRPC1/4/5 inhibitor with a conserved lipid binding site.

TRPC1/4/5 channels are non-specific cation channels implicated in a wide variety of diseases, and TRPC1/4/5 inhibitors have recently entered the first clinical trials. However, fundamental and translational studies require a better understanding of TRPC1/4/5 channel regulation by endogenous and exogenous factors. Although several potent and selective TRPC1/4/5 modulators have been reported, the paucity of mechanistic insights into their modes-of-action remains a barrier to the development of new chemical probes and drug candidates. The xanthine class of modulators includes the most potent and selective TRPC1/4/5 inhibitors described to date, as well as TRPC5 activators. Our previous studies suggest that xanthines interact with a, so far, elusive pocket of TRPC1/4/5 channels that is essential to channel gating. Targeting this pocket may be a promising strategy for TRPC1/4/5 drug discovery. Here we report the first structure of a small molecule-bound TRPC1/4/5 channel - human TRPC5 in complex with the xanthine Pico145 - to 3.0 [A]. We found that Pico145 binds to a conserved lipid binding site of TRPC5, where it displaces a bound phospholipid. Our findings explain the mode-of-action of xanthine-based TRPC1/4/5 modulators, and suggest a structural basis for TRPC1/4/5 modulation by endogenous factors such as (phospho)lipids and Zn2+ ions. These studies lay the foundations for the structure-based design of new generations of TRPC1/4/5 modulators.

molecular biology↗