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Biology subjects

Schneider, F.

Publications and source records attributed to Schneider, F..

At least 19 recordsLinked to original sources

Universal oligo adapters for high-efficiency DNA-barcoded antibody panel generation

DNA-barcoded antibodies are central to a broad range of spatial and dissociative assays and applications, including multiplexed imaging, single-cell profiling, and proximity detection. Direct modification of primary antibodies with defined DNA barcodes enables flexible panel design for multiplexed labeling of proteins. However, conventional antibody-oligonucleotide conjugation methods are inefficient, low-throughput, and prone to batch variability, limiting the reliable generation of orthogonally barcoded antibody panels. These challenges are particularly acute during initial panel development, where lengthy protocols, conjugation failures, large antibody input requirements, and the need for custom antibody formulations increase experimental cost and effort. Site-specific conjugation strategies based on antibody Fc-domain binders offer a promising alternative. We streamlined this foundational approach to establish its compatibility with multiplexed imaging in cells and tissues; however, generating a full barcoded library is still resource-intensive. This is because every unique DNA barcode must first be chemically linked to a separate binder before it can be attached to an antibody. To overcome the prominent bottleneck of rapidly and reliably generating DNA-barcoded antibody panels, we introduce the universal oligo adapter (UnO) strategy. UnO fundamentally changes the workflow from barcode-specific conjugation to universal barcode conversion. We build on the established photoreactive protein G binder and combine it with a universal oligonucleotide carrying a second ultrafast photocrosslinking group, 3-cyanovinylcarbazole (cnvK). This creates a dual-functional adapter: one photoreactive group enables covalent attachment to the antibody, while the cnvK-containing universal oligo simultaneously captures a user-defined DNA barcode through hybridization and UV crosslinking in a single step. Rather than preparing separate conjugation reactions for dozens of barcodes, UnO acts as a single reagent that covalently couples any desired barcode onto small quantities of off-the-shelf primary antibodies in minutes. We validate the generalizability and modularity of this approach across subcellular Immuno-SABER and tissue-based CODEX workflows for multiplex immunostaining. By converting antibody barcoding into a modular, one-step nucleic-acid adapter workflow, UnO reduces the cost, time, and complexity of generating DNA-barcoded antibody panels and provides an efficient, accessible solution to a central bottleneck in DNA-enabled multiplexed protein detection.

bioengineering↗

The Influence of Prior Precision on the Inference of Hidden Causes

Perception is widely understood as Bayesian inference, integrating prior expectations with sensory evidence to infer the most probable latent cause of a signal. A common assumption holds that precise priors dominate perception by pulling it strongly toward their mean. However, in hierarchically structured contexts where multiple latent causes compete, Bayesian inference predicts the opposite: imprecise priors can dominate perception under sensory uncertainty. We show that human observers exhibit this counterintuitive bias in an ecologically valid scenario of voice recognition: when classifying ambiguous utterances, observers preferentially attributed them to lower-precision (higher-variance) voice priors. This bias was strongest under high sensory ambiguity and increased with explicit knowledge of prior variance. Computational modeling revealed stable, idiosyncratic prior distributions, suggesting inference operates over hierarchically structured representations of voice identity. These findings identify prior precision as a key determinant of perceptual inference under competing priors.

neuroscience↗

Bright Probes, Blurred Metabolism: Navigating Fluorescent Protein Cross-Excitation in NADH FLIM

Fluorescence lifetime imaging microscopy (FLIM) of endogenous NAD(P)H enables the label-free assessment of cellular metabolic state. Although metabolic imaging is increasingly combined with fluorescent protein (FP) reporters to enhance biological specificity, the potential cross-talk between the intrinsic and extrinsic labels remain ill-defined. Here, we systematically evaluate cross-talk from FPs in metabolic FLIM using phasor analysis of two-photon fluorescence microscopy. The results clearly show that many widely used fluorescent proteins are excited under the conditions used for NADH imaging; they emit blue-shifted, short-lifetime fluorescence that can interfere with imaging NADH metabolic signatures. This overlap persists across excitation wavelengths and FP classes, posing a significant challenge for multiplexed metabolic imaging. This cautionary tale argues against unvalidated multiplexing strategies in metabolic FLIM studies. Our study aims to identify acceptable imaging partners, offer a pipeline for assaying potential cross-talk, and provide practical guidance for experimental design. SignificanceFluorescence lifetime imaging of NADH autofluorescence is a powerful, label-free approach to map cellular metabolism in living tissues. A growing number of studies combine NADH imaging with fluorescent protein (FP) reporters to simultaneously identify specific cell types or subcellular compartments. This study reveals that many FPs, spanning the visible spectrum, are unexpectedly excited under NADH conditions. Commonly used green, yellow, and red variants produce short-lifetime, blue-shifted fluorescence that directly overlaps with metabolic NADH signals. This cross-excitation can be falsely interpreted as a shift in cellular metabolic state, posing a significant risk for multiplexed metabolic imaging studies. Our studies establish a pipeline to assess and manage this risk. We identify StayGoldE138D and mNeonGreen as the most compatible FPs for co-imaging with NADH, and provide a practical framework to guide experimental design and control strategies for multiplexed metabolic FLIM.

biophysics↗

Quantitative comparison of fluorescent reporters by FCS excitation scan

Fluorescent reporters such as fluorescent proteins or chemigenetic indicators are indispensable tools for studying biological processes using light microscopy. Choosing an appropriate fluorescent tag is a crucial step in experimental design not only for imaging but also for quantitative measurements such as fluorescence fluctuation spectroscopy. Two key parameters should be considered: Fluorescent brightness and photo-bleaching. Change to fluorescence intensity due to photobleaching is relatively easy to assess in different biological environments, while brightness is more elusive. Here, we develop and employ a fluorescence correlation spectroscopy (FCS) based excitation scan assay that determines fluorescent protein performance and validate it in tissue culture and zebrafish embryos. We employ our FCS pipeline to compare a set of 10 established fluorescent proteins as well as HALO and SNAP tags for both cellular imaging and measurements of diffusion dynamics with FCS. We show that mNeonGreen outperforms mEGFP in tissue culture and zebrafish embryos. We also compare StayGold variants against other green fluorescent proteins and chemigenetic reporters in tissue culture. Overall, we present a broadly applicable approach for determining fluorescent reporter brightness in the living system of interest.

biophysics↗

Multivariate Transfer Entropy Quantifies Information Transfer Between Dyadic Partners During Real-Time Perceptual Decision-Making

1Many social behaviours unfold continuously in time, yet most studies of social influence rely on discrete, trial-based paradigms. To quantify how humans actually integrate sensory and social signals during ongoing perceptual decision-making we here apply an information-theoretic analysis to data obtained with the Continuous Perceptual Report (CPR) paradigm. In the CPR task, pairs of participants tracked a dynamic random-dot motion stimulus, continuously reporting perceived direction and their confidence. Crucially, each participant had access to their partners moment-by-moment direction and confidence reports embedded within the stimulus display. We quantified information flow between the stimulus and behavioural responses using multivariate transfer entropy, allowing us to detect whether participants acquired additional information from their partner once stimulus information had been received and integrated it into their behavioural response. We show that real-time social interactions predominantly occur within matching behavioural dimensions: partners perceptual choices influence participants own choices, and partners confidence influences participants confidence. Using both, more stimulus and social information contributed to improved task performance, and participants selectively acquired more information from better-performing partners. Crucially, information integration was flexibly modulated by stimulus reliability: as sensory evidence became noisier, participants relied more on social information, but only when interacting with a highly reliable (e.g. computer-controlled) partner. Latency analyses further revealed that participants responded faster to changes in their partners perceptual choices of direction than to changes in stimulus direction. They also responded more slowly to changes in their partners confidence than to changes in their partners choice of direction. Together, these findings demonstrate that humans dynamically and adaptively integrate social information in a time-continuous manner, and they establish multivariate information-theoretic analyses as a powerful framework for studying real-time social cognition.

animal behavior and cognition↗

Prolactin receptor localization and dynamics: Insights from quantitative imaging and mathematical modeling

Signal transduction through the prolactin receptor (PRLR) is crucial in pancreatic {beta}-cell pro-liferation, impacting pancreatic homeostasis. PRLR-induced JAK/STAT signaling is dynamic, involving changes in spatial organization of signaling molecules. Thus, the spatial organization of PRLR could have strong implications on signaling output. Internalization has been shown and modeled in other signaling pathways but has not been considered in a mathematical model of PRLR signaling. Here, we use live-cell fluorescence imaging, reconstitution approaches, and fluorescence correlation spectroscopy (FCS) to inform a mathematical model of PRLR signaling. Internal PRLR localization is observed in primary pancreatic tissue and in an engineered PRLR expression system. Our imaging data indicate the presence of intracellular and plasma membrane-bound receptor populations. We use FCS to resolve the membrane-bound PRLR population. Based on our data, we include internalization dynamics within an ordinary differential equation (ODE) model of PRLR signaling. We employ the model to explore how the spatial heterogeneity of PRLR affects downstream signaling. We show that the model is more sensitive to PRLR trafficking rates and ability to promote signaling than to its initial spatial distribution. Our data underscore the versatility of a modeling-imaging framework to quantitatively understand signal transduction in and beyond {beta}-cells. Significance StatementO_LIProlactin receptor (PRLR) signal transduction impacts the growth and survival of insulin-secreting cells, making this pathway a target for building our understanding of pancreatic homeostasis and exploring potential diabetes therapeutics. C_LIO_LILive fluorescence imaging techniques applied within an engineered PRLR expression platform indicate PRLR localization patterns consistent with primary pancreatic tissue and the presence of two spatially distinct PRLR populations. These observations inform a predictive mathematical model of PRLR signaling. C_LIO_LIIntegrating experimental data tailored to computational approaches shapes our understanding of complex, multiscale systems such as signal transduction. A generalizable modeling-imaging framework enables the study of molecular dynamics beyond {beta}-cells. C_LI

cell biology↗

Sensory sharpening and semantic prediction errors unify competing models of predictive processing in communication

The human brain makes abundant predictions in speech comprehension that, in real-world conversations, depend on conversational partners. Yet, tested models of predictive processing diverge on how such predictions are integrated with incoming speech: The brain may emphasise either expected information through sharpening or unexpected information through prediction error. We reconcile these views through direct neural evidence from electroencephalography showing that both mechanisms operate at different hierarchical levels during speech perception. Across multiple experiments, participants heard identical ambiguous speech in different speaker contexts. Using speech decoding, we show that listeners learn speaker-specific semantic priors, which sharpen sensory representations by pulling them toward expected acoustic signals. In contrast, encoding models leveraging pretrained transformers reveal that prediction errors emerge at higher linguistic levels. These findings support a unified model of predictive processing, wherein sharpening and prediction errors coexist at distinct hierarchical levels to facilitate both robust perception and adaptive world models.

neuroscience↗

At the Southern Limit: The Arenal Central Site and the Guarani Occupation of the Parana Delta (Argentina)

This study analyzes the archaeological record of the Arenal Central site, a Guarani residential base located on Martin Garcia Island, within the Rio de la Plata estuary--marking the southernmost extent of this population originating from the tropical forests of South America. The results significantly advance our understanding of these Amazonian forager-horticulturalists in the region, allowing us to explore a range of strategies and material culture expressions developed in an environment suboptimal for canoe-based populations. The study also presents a new set of chronological data, substantially increasing the number of radiocarbon dates available for these groups in the area. Findings indicate that Arenal Central was occupied around 1400 CE, during the final phase of the Guarani expansion across the La Plata Basin. From this location, a vast catchment area was incorporated, including the lower Uruguay River, the Parana Delta islands, and the adjacent Uruguayan steppe. The extensive use of territory appears to have been a strategic response to the islands limited carrying capacity and the scarcity of key resources required to sustain the Guarani ecological niche. While the recovered assemblage preserves the core features of Guarani material culture, a marked decline is observed in the complexity of pictorial expressions--particularly in painted ceramics. This simplification may reflect reduced intra-ethnic interaction, likely due to the low density of Guarani populations in the surrounding area, as well as the challenges imposed by a constrained insular setting. We also compare subsistence strategies and ceramic assemblages from other sites that have been excavated and analyzed following comparable standards. Finally, the results are contextualized within the broader process of Guarani occupation of the Parana Delta and the Rio de la Plata estuary.

zoology↗

Spectral STED microscopy improves spectral sensitivity with polarity-sensitive probes and enables correlative measurements of membrane order and anomalous lipid diffusion

Molecular plasma membrane organization and dynamics play an important role in cellular signalling. Advances in our understanding of the nanoscale architecture of the plasma membrane heavily rely on the development of non-invasive experimental methods, particularly of advanced fluorescence microscopy and spectroscopy techniques with high spatio-temporal resolution and sensitivity to local molecular properties. However, it remains difficult to combine several of them for a multimodal characterisation that would reduce the possibility of misinterpretations. Here, we integrated a spectral detector into a super-resolution stimulated emission depletion (STED) microscope, achieving three goals. First, we show that compared to the standard ratiometric detection using fixed bandpass filters, the spectrally resolved acquisition together with spectral fitting or phasor analysis improves the accuracy of experiments determining membrane lipid order with polarity-sensitive probes multifold. Secondly, we demonstrate that this acquisition scheme allows the use of such probes in combination with other dyes with overlapping spectra, enabling co-localisation of the membrane order maps with other cellular structures of interest, e.g. fluorescently labelled proteins. Finally, we correlate the obtained membrane lipid order with the anomalous trapped diffusion properties of a fluorescent sphingomyelin lipid analogue in the plasma membrane of living cells, as determined by STED fluorescence correlation spectroscopy, and highlight that some of the most apparent trapping sites locate at the boundaries of local ordered environments discernible by the introduced spectral STED microscopy. With additional measurements in model membranes and Monte-Carlo simulations we conclude that for sub-100 nm ordered environments uneven probe partitioning cannot by itself explain the trapping diffusion of SM in cells.

biophysics↗

Confidence over competence: Real-time integration of social information in human continuous perceptual decision-making

Human perceptual decision-making is susceptible to social influences. To determine if and how individuals opportunistically integrate real-time social information about noisy stimuli into their judgment, we tracked perceptual accuracy and confidence in social (dyadic) and non-social (solo) settings using a novel continuous perceptual report (CPR) task with peri-decision wagering. In the dyadic setting, most participants showed a higher degree of perceptual confidence. In contrast, average accuracy did not improve compared to solo performance. Underlying these net effects, partners in a dyad exhibit mutual convergence of accuracy and confidence, benefiting less competent or confident individuals, at the expense of the better-performing partner. In conclusion, real-time social information asymmetrically shapes human perceptual decision-making, with most dyads expressing more confidence without a matching gain in overall competence.

neuroscience↗

Far-red chemigenetic biosensors for multi-dimensional and super-resolved kinase activity imaging

Fluorescent biosensors revolutionized biomedical science by enabling the direct measurement of signaling activities in living cells, yet the current technology is limited in resolution and dimensionality. Here, we introduce highly sensitive chemigenetic kinase activity biosensors that combine the genetically encodable self-labeling protein tag HaloTag7 with bright far-red-emitting synthetic fluorophores. This technology enables five-color biosensor multiplexing, 4D activity imaging, and functional super-resolution imaging via stimulated emission depletion (STED) microscopy.

bioengineering↗

Single-cell phenomics reveals behavioural and mechanical heterogeneities underpinning collective migration during mouse anterior patterning

Distal Visceral Endoderm (DVE) cells show a stereotypic unidirectional migration essential for correct orientation of the anterior-posterior axis. They migrate within a simple epithelium, the Visceral Endoderm (VE). It is unknown how DVE cells negotiate their way amongst the surrounding VE cells, what determines the bounds of DVE migration within the VE, and the relative contributions of different cell behaviours to this migration. To address these questions, we used lightsheet microscopy to generate a multi-embryo, singlecell resolution, longitudinal dataset of cell behaviour and morphology. We developed a machine learning based pipeline to segment cells and a data-informed systematic computational framework to extract and compare select morphological, behavioural and molecular parameters of all VE cells in a unified coordinate space. Unbiased clustering of this single-cell phenomic dataset reveals considerable patterned phenotypic heterogeneity within the VE and a previously unknown sub-grouping within the DVE. While migrating, DVE cells retain regular morphology, do not exchange neighbours and are crowded, all hallmarks of the jammed state. In contrast, VE cells immediately ahead of them deform and undergo neighbour exchange. We show that DVE cells are characterised by higher levels of apical F-actin and elevated tension relative to the VE cells immediately ahead of them through which they migrate, but stop migrating upon reaching a region of the VE with matching elevated tension. Lefty1 mutants, known to show abnormal over-migration of DVE cells, show disruption to this patterned tension in the VE. Our findings provide novel insights into the control of cell behaviour during the remodelling of curved epithelia, indicating that the collective migration of sub-sets of cells can be circumscribed by modulating the mechanical properties of surrounding cells and that migrating cells in this context remain as a jammed solid flock, with surrounding cells facilitating their movement by becoming unjammed. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=195 HEIGHT=200 SRC="FIGDIR/small/534937v1_ufig1.gif" ALT="Figure 1"> View larger version (53K): org.highwire.dtl.DTLVardef@10a7153org.highwire.dtl.DTLVardef@963a1forg.highwire.dtl.DTLVardef@c1fcd0org.highwire.dtl.DTLVardef@1bcdded_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

Deep learning for histopathological subtyping and grading of lung adenocarcinoma

The histopathological distinction of lung adenocarcinoma (LADC) subtypes is subject to high inter-observer variability, which can compromise the optimal assessment of the patient prognosis. Therefore, this study developed convolutional neural networks (CNNs) capable of distinguishing LADC subtypes and predicting disease-specific survival, according to the LADC tumour grades established recently by the International Association for the Study of Lung Cancer pathology committee. Consensus LADC ground truth histopathological images were obtained from seventeen expert pulmonary pathologists and one pathologist in training. Two deep learning models (AI-1 and AI-2) were trained with EfficientNet b3 architecture to predict eight different LADC classes (lepidic, acinar, papillary, micropapillary, solid, invasive mucinous adenocarcinoma, other carcinoma types, and no carcinoma cells). Furthermore, the trained models were tested on an independent cohort of 133 patients. The models achieved high precision, recall, and F1-scores exceeding 0.90 for most of the LADC classes. Clear stratification of the three LADC grades was reached in predicting the disease-specific survival by the two models. Moreover, the grading prediction of one of the trained models was more accurate than those of 14 out of 15 pulmonary pathologists involved in the study (p=0.0003). Both trained models showed high stability in the segmentation of each pair of predicted grades with low variation in the hazard ratio across 200 bootstrapped samples. These findings indicate that the trained CNNs improve the diagnostic accuracy of the pathologist, standardise LADC subtype recognition, and refine LADC grade assessment. Thus, the trained models are promising tools that may assist in the routine evaluation of LADC subtypes and grades in clinical practice.

pathology↗

The kinase occupancy of T-cell coreceptors reconsidered

The sensitivity of the {beta} T-cell receptor (TCR) is enhanced by the coreceptors CD4 and CD8{beta}, which are expressed primarily by cells of the helper and cytotoxic T-cell lineages, respectively. The coreceptors bind to major histocompatibility complex (MHC) molecules and associate intracellularly with the Src-family kinase Lck, which catalyzes TCR phosphorylation during receptor triggering. Although coreceptor-kinase occupancy was initially believed to be high, a recent study suggested that most coreceptors exist in an Lck-free state, and that this low occupancy helps to effect TCR antigen discrimination. Here, using the same method, we found instead that the CD4-Lck interaction was stoichiometric (~100%) and that the CD8{beta}-Lck interaction was also substantial (~60%). We confirmed our findings in live cells using fluorescence cross-correlation spectroscopy (FCCS) to measure coreceptor-Lck co-diffusion in situ. After introducing structurally guided mutations into the intracellular domain of CD4, we used FCCS to show that stoichiometric Lck coupling required an amphipathic -helix present in CD4 but not CD8. In double-positive cells expressing equal numbers of both coreceptors, but limiting amounts of kinase, CD4 out-competed CD8{beta} for Lck. In T cells, TCR signaling induced CD4-Lck oligomerization but did not affect the high levels of CD4-Lck occupancy. These findings help settle the question of kinase occupancy and suggest that the binding advantages that CD4 has over CD8 could be important when Lck levels are limiting. Significance statementCD4 and CD8{beta} are archetypal coreceptor proteins that potently enhance T-cell antigen sensitivity but how they function is still debated. A fundamental question that remains incompletely resolved is: what fractions of the coreceptors bind the signal-initiating kinase, Lck? Using in vitro assays and non-invasive fluorescence fluctuation spectroscopy in live cells, we show that most coreceptors are occupied by Lck at the surface of live cells. The structural basis for important differences in the kinase occupancy of CD4 and CD8{beta} is also identified. These results provide important context for refining current models of both TCR antigen recognition and cell fate decisions made during thymopoiesis.

immunology↗

Single-cell resolution unravels spatial alterations in metabolism, transcriptome and epigenome of ageing liver

Epigenetic ageing clocks have revealed that tissues within an organism can age with different velocity. However, it has not been explored whether cells of one type experience different ageing trajectories within a tissue depending on their location. Here, we employed lipidomics, spatial transcriptomics and single-cell ATAC-seq in conjunction with available single-cell RNA-seq data to address how cells in the murine liver are affected by age-related changes of the microenvironment. Integration of the datasets revealed zonation-specific and age-related changes in metabolic states, the epigenome and transcriptome. Particularly periportal hepatocytes were characterized by decreased mitochondrial function and strong alterations in the epigenetic landscape, while pericentral hepatocytes - despite accumulation of large lipid droplets - did not show apparent functional differences. In general, chromatin alterations did not correlate well with transcriptional changes, hinting at post-transcriptional processes that shape gene expression during ageing. Together, we provide evidence that changing microenvironments within a tissue exert strong influences on their resident cells that can shape epigenetic, metabolic and phenotypic outputs.

cell biology↗

Single organoid RNA-sequencing reveals high organoid-to-organoid variability

Over the last decades, organoids have been established from the majority of tissue resident stem and iPS cells. They hold great promise for our understanding of mammalian organ development, but also for the study of disease or even personalized medicine. In recent years, several reports hinted at intraculture organoid variability, but a systematic analysis of such a heterogeneity has not been performed before. Here, we used RNA-seq of individual organoids to address this question. Importantly, we find that batch-to-batch variation is very low, even when prepared by different researchers. On the other hand, there is organoid-to-organoid variability within a culture. Using differential gene expression, we did not identify specific pathways that drive this variability, pointing towards possible effects of the microenvironment within the culture condition. Taken together, our study provides a framework for organoid researchers to properly consider experimental design.

cell biology↗

Diffusion and interaction dynamics of the cytosolic peroxisomal import receptor PEX5

Measuring diffusion dynamics in living cells is essential for the understanding of molecular interactions. While various techniques have been used to explore such characteristics in the plasma membrane, this is less developed for measurements inside the cytosol. An example of cytosolic action is the import of proteins into peroxisomes, via the peroxisomal import receptor PEX5. Here, we combined advanced microscopy and spectroscopy techniques such as fluorescence correlation spectroscopy (FCS) and super-resolution STED microscopy to present a detailed characterization of the diffusion and interaction dynamics of PEX5. Among other features, we disclose a slow diffusion of PEX5, independent of aggregation or target binding, but associated with cytosolic interaction partners via its N-terminal domain. This sheds new light on the functionality of the receptor in the cytosol. Besides specific insights, our study highlights the potential of using complementary microscopy tools to decipher molecular interactions in the cytosol via studying their diffusion dynamics. SummaryThe peroxisomal import receptor PEX5 transports newly synthesized proteins from the cytosol to the peroxisomal matrix. Here the cytosolic diffusion and interaction dynamics of PEX5 are characterized by advanced microscopic spectroscopy methods, revealing a so far unknown interaction partner.

biophysics↗

rasterdiv - an Information Theory tailored R package for measuring ecosystem heterogeneity from space: to the origin and back

O_LIEcosystem heterogeneity has been widely recognized as a key ecological feature, influencing several ecological functions, since it is strictly related to several ecological functions like diversity patterns and change, metapopulation dynamics, population connectivity, or gene flow. C_LIO_LIIn this paper, we present a new R package - rasterdiv - to calculate heterogeneity indices based on remotely sensed data. We also provide an ecological application at the landscape scale and demonstrate its power in revealing potentially hidden heterogeneity patterns. C_LIO_LIThe rasterdiv package allows calculating multiple indices, robustly rooted in Information Theory, and based on reproducible open source algorithms. C_LI

ecology↗