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Search indexed bioRxiv preprints in genomics, neuroscience, cell biology and bioinformatics. Read source abstracts and check manuscript versions; preprints are not peer reviewed.

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At least 55 records · Page 3Linked to original sources

Notebook-based alignment of human and agentic reasoning in single-cell biology

Agentic AI is increasingly deployed on complex problems, often using chain-of-thought prompting to ground predictions in stepwise reasoning. In biomedical research, assistive agents could make this reasoning accessible to human scientists: for example, intermediate conclusions could be critically evaluated based on shared reasoning and sycophancy - the tendency to affirm a users claims regardless of their validity - could be mitigated. However, this interaction requires an alignment of reasoning between agents and humans that is difficult when multiple data modalities are considered, for example in single-cell biology, where human scientists reason through computational notebooks that contain code, results, and text. To address this issue, we developed kai, an agentic AI that iteratively generates analyses in computational notebooks. We find that kai can flexibly use multiple tools in sequence to solve complex cell type annotation problems. Compared with one-shot generation, kai demonstrates improved robustness against code errors and sycophancy, improved reasoning, and the ability to formulate and address questions on data. kais design is model-agnostic and, therefore, scales directly with advancements in large language models.

bioinformatics↗

Studentsourcing - aggregating and re-using data from a practical cell biology course

Practical courses mimic experimental research and may generate valuable data. Yet, data that is generated by students during a course is often lost as there is no centrally organized collection and storage of the data. The loss of data prevents its re-use. To provide access to these data, I present an approach that I call studentsourcing. It collects, aggregates and reuses data that is generated by students in a practical course on cell biology. The course runs annually, and I have recorded the data that was generated by >100 students over 3 years. Two use cases illustrate how the data can be aggregated and re-used either for the scientific record or for teaching. As the data is obtained by different students, in different groups, over different years, it is an excellent opportunity to discuss experimental design and modern data visualization methods such as the superplot. The first use case demonstrates how the data can be presented as an online, interactive dashboard, providing real-time data of the measurements. The second use case shows how central data storage provides a unique opportunity to get precise quantitative data due to the large sample size. Both use cases illustrate how data can be effectively aggregated and re-used. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=169 SRC="FIGDIR/small/561479v2_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@13c8973org.highwire.dtl.DTLVardef@1641e47org.highwire.dtl.DTLVardef@1fff83eorg.highwire.dtl.DTLVardef@2c1ef_HPS_FORMAT_FIGEXP M_FIG C_FIG

scientific communication and education↗

Pharmacological modulation of the cytosolic oscillator affects glioblastoma cell biology

The circadian system is a conserved time-keeping machinery that regulates a wide range of processes such as sleep/wake, feeding/fasting, and activity/rest cycles to coordinate behavior and physiology. Circadian disruption can be a contributing factor in the development of metabolic diseases, inflammatory disorders, and higher risk of cancer. Glioblastoma (GBM) is a highly aggressive grade 4 brain tumor that is resistant to conventional therapies and has a poor prognosis after diagnosis, with a median survival of only 12-15 months. GBM cells kept in culture were shown to contain a functional circadian oscillator. In seeking more efficient therapies with lower side effects, we evaluated the pharmacological modulation of the circadian clock by targeting the cytosolic kinases glycogen synthase kinase-3 (GSK-3) and casein kinase {varepsilon}/{delta} (CK1{varepsilon}/{delta}) with specific inhibitors (CHIR99022 and PF670462, respectively), the cryptochrome protein stabilizer (KL001), or circadian disruption after Per2 knockdown expression in GBM-derived cells. CHIR99022-treated cells had a significant effect on cell viability, clock protein expression, migration, and cell cycle distribution. Moreover, cultures exhibited higher levels of reactive oxygen species and alterations in lipid droplet content after GSK-3 inhibition as compared with control cells. The combined treatment of CHIR99022 with temozolomide was found to improve the effect on cell viability compared to temozolomide therapy alone. Per2 disruption affected both GBM migration and cell cycle progression. Overall, our results suggest that pharmacological modulation or molecular clock disruption severely affects glioblastoma cell biology.

cancer biology↗

Neural crest cell biology shapes lizard skull evolution across evolutionary time scales

The vertebrate skull originates from two embryonic lineages, the mesoderm and the neural crest, offering a unique framework to study how developmental mechanisms connect phenotypic variation and evolutionary diversification. Using 3D geometric morphometrics, we analysed skull shape variation in lacertid lizards. Mesoderm- and neural crest-derived bones formed distinct, conserved modules at both micro- and macroevolutionary scales. In the common wall lizard (Podarcis muralis), rapid evolution of skull shape under sexual selection was primarily driven by neural crest-derived bones. While the primary axis of shape divergence in P. muralis aligned with a major axis of variation across lacertids, neural crest-derived bones exhibited slower evolutionary rates and lower morphological disparity than mesodermal-derived bones. We propose that this discrepancy between the role of the neural crest for skull evolution on micro- and macroevolution reflects constraints imposed by neural crest cell biology: although developmental plasticity enables rapid, correlated responses under sexual selection, pleiotropy may limit long-term evolvability of neural crest-derived skull regions. Teaser textThe bones of the vertebrate skull come from two developmental sources: the mesoderm and the neural crest. This dual origin allows to study how development influences evolution. Using 3D models of lizard skulls--including a species with exaggerated male traits linked to the neural crest--we examined patterns of skull variation. We found that neural crest-derived bones contribute to rapid changes driven by sexual selection. However, across different species, these same skull regions evolve more slowly and show less variation. This suggests that while neural crest cells may constrain long-term evolution because of their wide influence, they can also enable fast adaptations. The developmental biology of a trait therefore shapes its evolution.

evolutionary biology↗

Four assessment methods to measure student gains in a graduate course on mathematical modeling in cell biology

The push for mathematics and quantitative skill development in biology is greater than ever before. The perceptions of these techniques are a barrier to their implementation on a grand scale. Methods to assess the efficacy of approaches to teaching quantitative skills are needed to determine if they effectively overcome social stereotypes and fears of math. In our project we study the effect of a mathematical modeling course in cell biology. We developed four assessments to understand if hands-on modeling increases student understanding of the concepts while simultaneously reducing fear of math. Two concept inventories track students learning gains both in general and specific knowledge to the course content. Two surveys quantify students quantitative confidence and opinions of the usefulness of these techniques in biology. We discuss the effectiveness of our methods and the implications for assessment development in mathematical biology education.

scientific communication and education↗

Scientific societies advancing STEM workforce diversity: Lessons and Outcomes from the Minorities Affairs Committee of the American Society for Cell Biology

Promoting diversity and inclusiveness in the STEM academic workforce remains a key challenge and national priority. Scientific societies can play a significant role in this process through the creation and implementation of programs to foster STEM academic workforce diversification, and by providing mentoring and skills development training that empower scientists from under-represented minority (URM) backgrounds to succeed in their communities of practice. In this article, we provide examples of challenges met by scientific societies in these areas and present data from the American Society for Cell Biology, highlighting the benefits received by trainees through long-term engagement with its programs. The success of these initiatives illustrates the impact of discipline-specific programming by scientific societies in supporting the development of URM scientists and an increasingly diverse and inclusive academic STEM community.

scientific communication and education↗

EXPLORING THE EFFECTS OF METABOLISM-DISRUPTING CHEMICALS ON PANCREATIC alpha-CELL BIOLOGY: A SCREENING TESTING APPROACH

Humans are constantly exposed to many environmental pollutants, some of which have been largely acknowledged as key factors in the development of metabolic disorders such as diabetes and obesity. These chemicals have been classified as endocrine-disrupting chemicals (EDCs) and, more recently, since they can interfere with metabolic functions, they have been renamed as metabolism-disrupting chemicals (MDCs). MDCs are present in many consumer products, including food packaging, personal care products, plastic bottles and containers, and detergents. The scientific literature has ever-increasingly focused on insulin-releasing pancreatic {beta}-cells as one of the main targets for MDCs. Evidence highlights that these substances may disrupt glucose homeostasis, altering pancreatic {beta}-cell physiology. However, their potential impact on glucagon-secreting pancreatic -cells remains poorly known despite the essential role that this cellular type plays in controlling glucose metabolism. In the present study, we have selected seven paradigmatic EDCs representing major toxic classes, including bisphenols, phthalates, perfluorinated compounds, metals, and pesticides. By using an in vitro cell-based model, the pancreatic -cell line TC1-9, we have explored the effects of these compounds on pancreatic -cell viability, gene expression, and secretion. Our results indicated that most of the selected chemicals studied caused functional alterations in pancreatic -cells. Moreover, we revealed, for the first time, their direct effects on key molecular aspects of pancreatic -cell biology.

pharmacology and toxicology↗

Genetic tool development in marine protists: Emerging model organisms for experimental cell biology

Diverse microbial ecosystems underpin life in the sea. Among these microbes are many unicellular eukaryotes that span the diversity of the eukaryotic tree of life. However, genetic tractability has been limited to a few species, which do not represent eukaryotic diversity or environmentally relevant taxa. Here, we report on the development of genetic tools in a range of protists primarily from marine environments. We present evidence for foreign DNA delivery and expression in 13 species never before transformed and advancement of tools for 8 other species, as well as potential reasons for why transformation of yet another 17 species tested was not achieved. Our resource in genetic manipulation will provide insights into the ancestral eukaryotic lifeforms, general eukaryote cell biology, protein diversification and the evolution of cellular pathways.

ecology↗

Humanized mice enable in vivo evaluation of engineered plasma cell biology and therapeutic function

Engineered plasma cells (ePCs) offer a durable strategy for in vivo delivery of therapeutic antibodies, but standard immunodeficient mouse models lack human immune factors critical for plasma cell survival and function. We utilized a humanized mouse model in which NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice were engrafted with human CD34+ stem cells as recipients for infusions with autologous ePCs. In this setting, ePCs localized to plasma cell niches and stably secreted antibodies for over three months. To improve the selection of antibodies for secretion, we developed a B cell receptor surface display screen that identified candidate antibody sequences with high secretion potential. An anti-SARS-CoV-2 antibody (clone 297) selected by this method showed robust secretion both in vitro and vivo, and serum from ePC-engrafted mice potently neutralized SARS-CoV-2 pseudovirus. Together, these findings establish a physiologically relevant model for testing human ePCs, and offer a generalizable strategy for optimizing antibody selection to support long-term therapeutic delivery.

molecular biology↗

Consequences of training data composition for deep learning models in single-cell biology

Foundation models for single-cell transcriptomics have the potential to augment (or replace) purpose-built tools for a variety of common analyses, especially when data are sparse. Recent work with large language models has shown that training data composition greatly shapes performance; however, to date, single-cell foundation models have ignored this aspect, opting instead to train on the largest possible corpus. We systematically investigate the consequences of training dataset composition on the behavior of deep learning models of single-cell transcriptomics, focusing on human hematopoiesis as a tractable model system and including cells from adult and developing tissues, disease states, and perturbation atlases. We find that (1) these models generalize poorly to unseen cell types, (2) adding malignant cells to a healthy cell training corpus does not necessarily improve modeling of unseen malignant cells, and (3) including an embryonic stem cell differentiation atlas during training improves performance on out-of-distribution tasks. Our results emphasize the importance of diverse training data and suggest strategies to optimize future single-cell foundation models.

genomics↗

Cell-type-specific resolution epigenetics without the need for cell sorting or single-cell biology

High costs and technical limitations of cell sorting and single-cell techniques currently restrict the collection of large-scale, cell-type-specific DNA methylation data. This, in turn, impedes our ability to tackle key biological questions that pertain to variation within a population, such as identification of disease-associated genes at a cell-type-specific resolution. Here, we show mathematically and empirically that cell-type-specific methylation levels of an individual can be learned from its tissue-level bulk data, conceptually emulating the case where the individual has been profiled with a single-cell resolution and then signals were aggregated in each cell population separately. Provided with this unprecedented way to perform powerful large-scale epigenetic studies with cell-type-specific resolution, we revisit previous studies with tissue-level bulk methylation and reveal novel associations with leukocyte composition in blood and with rheumatoid arthritis. For the latter, we further show consistency with validation data collected from sorted leukocyte sub-types. Corresponding software is available from: https://github.com/cozygene/TCA.

bioinformatics↗

ISiCell: involving biologists in the design process of agent-based models in cell biology

Agent-based models are commonly used in biology to study tissue-scale phenomena by reproducing the individual behavior of the cells. They offer the possibility to study cellular biology at the individual cell scale to explore the basic behavior of cells which are responsible of the emergence of more complex phenomena at the tissue scale. Additionally, they can produce a predictive tool that will help taking decisions for biologic experiments based on in silico simulations. However these models require a good intercomprehension between the biologists and the modelers and thus it may take weeks or months to end up providing a usable prototype. To address this limitation, we propose a new methodology to facilitate the dialog between biologists and modelers and improve biologists involvement in the design of the model. For this purpose, UML diagrams, in particular, state-transition and activity diagrams, are used. They allow a better comprehension of the model for the biologists and offer a general frame for structuring models. Visualization of simulations is also used to have qualitative feedbacks from the biologist on the model. They are instrumental to validate or refine the prototype before exploring it. Alongside this methodology, we propose a web platform that enables to build state-transition and activity diagrams to describe a model and translate them into code. The generated code is then compiled on-the-fly and simulations are ready to visualize and explore. The platform also disposes of tools to directly visualize and manually explore the model. These tools allow for qualitative validation of the model and additional interaction with the biologists. Finally in this article, we show the capacity of our platform to reproduce models from the literature and to build new models starting from workshops with biologists. Its range of application is wide and includes immunology, oncology or cell biology. Author summaryWe developed a methodology based on diagrams to facilitate the dialog between computer scientists and biologists when building in silico models. The main idea is to limit misunderstandings and improve the involvement of the biologists in the prototyping process. For this purpose, we use visual methods to simplify the modeling phase. Alongside this methodology, we propose a web platform, called ISiCell, which enables to visually code thanks to diagrams that will be translated into code. The platform allows for compiling the generated code on the fly and to visualize and explore the model directly with the platform. The strong advantage of the platform is that one day workshop biologist/modeler allows to build new models. Additionally, we were able to reproduce models from the literature within the modeling platform showing the versatility of the tool. Our long-term objective is to use our methodology and platform in new contexts to develop new models. We intend the make the platform more user friendly in order to expand the community of users. Involving biologists in the conception of in silico models might improve their acceptability in the community.

systems biology↗

A transcriptional continuum links viral burden and host-cell biology in human lymphoid tissue

Human immunodeficiency virus (HIV-1) persistence in lymphoid tissue remains a major barrier to cure, yet infected cells are commonly represented using discrete categories that may obscure biologically meaningful heterogeneity. Using an ex vivo human tonsil explant model and single-cell RNA sequencing of more than 42,000 T cells, we show that HIV transcription spans a structured continuum and that viral transcriptional burden functions as an organizing axis of host-cell biology. Across the continuum, increasing HIV transcription is associated with coordinated remodeling of immune, inflammatory, metabolic, and redox-associated programs. Lower transcriptional tiers were enriched for innate sensing and inflammasome-associated responses, whereas higher tiers exhibited activation of oxidative phosphorylation and redox-buffering pathways. Antiretroviral therapy preferentially depleted highly transcriptionally active populations while preserving lower and intermediate tiers, resulting in compression rather than elimination of the continuum. Together, these findings provide a quantitative framework for interpreting HIV transcriptional heterogeneity within human lymphoid tissue and suggest that persistent viral activity reflects a spectrum of host-virus states rather than a single infected-cell population. By linking viral transcriptional burden to distinct host-cell programs, this framework may inform future strategies to reduce HIV persistence and its associated inflammatory consequences.

immunology↗

Outcome-Driven Microscopy: Closed-Loop Optogenetic Control of Cell Biology

Smart microscopy is transforming biological imaging by integrating real-time analysis with adaptive acquisition to enhance imaging efficiency. Whereas many emerging implementations are event-driven and focus on on-demand data acquisition to reduce phototoxicity, we here present outcome-driven microscopy, which combines smart microscopy with optogenetics to achieve subcellular spatiotemporal control of biology to predefined outcomes. We validate this approach using light-based control of cell migration and nucleocytoplasmic transport, and demonstrate unprecedented spatiotemporal control over cellular behaviour.

cell biology↗

Reaction-diffusion patterning of DNA-based artificial cells

Biological cells display complex internal architectures, with distinct micro environments that establish the chemical heterogeneity needed to sustain cellular functions. The continued efforts to create advanced cell mimics - artificial cells - demands strategies to construct similarly heterogeneous structures with localized functionalities. Here, we introduce a platform for constructing membrane-less artificial cells from the self-assembly of synthetic DNA nanostructures, in which internal domains can be established thanks to prescribed reaction-diffusion waves. The method, rationalized through numerical modeling, enables the formation of up to five distinct, concentric environments, in which functional moieties can be localized. As a proof-of-concept, we apply this platform to build DNA-based artificial cells in which a prototypical nucleus synthesizes fluorescent RNA aptamers, which then accumulate in a surrounding storage shell, thus demonstrating spatial segregation of functionalities reminiscent of that observed in biological cells.

synthetic biology↗

Pfcerli2, a duplicated gene in the malaria parasite Plasmodium falciparum essential for invasion of erythrocytes as revealed by phylogenetic and cell biological analysis.

Merozoite invasion of host red blood cells (RBCs) is essential for survival of the human malaria parasite Plasmodium falciparum. Proteins involved with RBC binding and invasion are secreted from dual-club shaped organelles at the apical tip of the merozoite called the rhoptries. Here we characterise P. falciparum Cytosolically Exposed Rhoptry Leaflet Interacting protein 2 (PfCERLI2), as a rhoptry bulb protein that is essential for merozoite invasion. Phylogenetic analyses show that cerli2 arose through an ancestral gene duplication of cerli1, a related cytosolically exposed rhoptry bulb protein. We show that PfCERLI2 is essential for blood-stage growth and localises to the cytosolic face of the rhoptry bulb. Inducible knockdown of PfCERLI2 led to an inhibition of merozoite invasion after tight junction formation. PfCERLI2 knockdown was associated with inhibition of rhoptry antigen processing and a significant elongation of the rhoptries, suggesting that the inability of merozoites to invade is caused by aberrant rhoptry function due to PfCERLI2 deficiency. These findings identify PfCERLI2 as a protein that has key roles in rhoptry biology during merozoite invasion.

microbiology↗

Information Theory and Stem Cell Biology

Purpose of ReviewTo outline how ideas from Information Theory may be used to analyze single cell data and better understand stem cell behaviour.\n\nRecent findingsRecent technological breakthroughs in single cell profiling have made it possible to interrogate cell-to-cell variability in a multitude of contexts, including the role it plays in stem cell dynamics. Here we review how measures from information theory are being used to extract biological meaning from the complex, high-dimensional and noisy datasets that arise from single cell profiling experiments. We also discuss how concepts linking information theory and statistical mechanics are being used to provide insight into cellular identity, variability and dynamics.\n\nSummaryWe provide a brief introduction to some basic notions from information theory and how they may be used to understand stem cell identities at the single cell level. We also discuss how work in this area might develop in the near future.

cell biology↗

Exploring new dimensions of immune cell biology in Anopheles gambiae through genetic immunophenotyping

Mosquito immune cells, or hemocytes, are integral components of the innate immune responses that define vector competence. However, the lack of genetic resources has limited their characterization and our understanding of their functional roles in immune signaling. To overcome these challenges, we engineered transgenic Anopheles gambiae that express fluorescent proteins under the control of candidate hemocyte promoters. Following the characterization of five transgenic constructs through gene expression and microscopy-based approaches, we examine mosquito immune cell populations by leveraging advanced spectral imaging flow cytometry. Our results comprehensively map the composition of mosquito hemocytes, classifying them into twelve distinct populations based on size, granularity, ploidy, phagocytic capacity, and the expression of PPO6, SPARC, and LRIM15 genetic markers. Together, our novel use of morphological properties and genetic markers provides increased resolution into our understanding of mosquito hemocytes, highlighting the complexity and plasticity of these immune cell populations, while providing the foundation for deeper investigations into their roles in immunity and pathogen transmission.

genetics↗