Biology subjects

Bi, C.

Publications and source records attributed to Bi, C..

At least 19 recordsLinked to original sources

bioRxiv2026

Mouse behavioral genomics identifies Creld1 as a gatekeeper of somatosensation

Somatosensation enables the perception of touch, temperature, pain, and itch. These sensory modalities are mediated by primary sensory neurons in the dorsal root ganglion (DRG), which convert physical and chemical stimuli into electrical signals using specialized molecular sensors, including the touch sensor PIEZO2 (Ref1,2) and temperature sensors such as TRPV1 (Ref3,4), coupled with downstream voltage-gated sodium channels (Nav) like Nav1.7 (Ref5,6). However, the full repertoire of molecular components involved in somatosensory processing remains incompletely identified. Here, we developed an efficient postnatal CRISPR-Cas9 knockout platform to screen DRG-expressed genes via AAV9-sgRNA delivery. Combining this approach with behavioral assays of somatosensory responses, we validated the roles of PIEZO2 and TRPV1 in sensing gentle touch and noxious heat, respectively, and the broad involvement of Nav1.7 in distinct somatosensory modalities. Remarkably, a targeted screen of 20 DRG-expressed genes identified the Cysteine-rich with EGF-like domains 1 (Creld1) as a master regulator of somatosensation. Either sgRNA-mediated postnatal knockout or tamoxifen-induced Cre-mediated deletion of Creld1 in DRG neurons resulted in profound behavioral deficits in touch, temperature, pain, and itch perception, while its overexpression enhanced touch and thermal responses. Mechanistically, Creld1 functions as a novel auxiliary regulator of Nav for controlling the excitability of DRG neurons. The biochemical interaction and functional modulation of Nav by mouse Creld1 are mediated via its C-terminal transmembrane region. Notably, this domain is conserved in mouse Creld1 and some isoforms of human CRELD1, resulting in an isoform-dependent regulation of Nav1.7. Together, this work establishes a robust postnatal screening platform for somatosensory genomics and identifies Creld1 as a master regulator of somatosensory function, and provides novel therapeutic strategy for pain and itch treatment.

neuroscience↗

bioRxiv2026

Abscisic acid binds to an Arabidopsis thaliana phosphodiesterase and tunes its activity

Growing evidence suggests that plant proteomes contain numerous proteins that specifically bind abscisic acid (ABA). Many of them are complex multidomain proteins where specific ABA-binding can cause biochemical and physiological changes. Here we show that the Arabidopsis thaliana K+ transporter AtKUP5 contains both a functional cytoplasmic N-terminal adenylate cyclase (AC) enabling the synthesis of 3,5-cAMP from ATP and a C-terminal phosphodiesterase (PDE) that hydrolyses 3,5-cAMP to 5-AMP. We found that ABA binds in a ligand-specific manner to the catalytic center of the PDE thereby causing a reduction of 3,5-cAMP hydrolysis in vitro. The hydrolytic activity of the PDE is ABA concentration-dependent, biphasic and requires the presence of an intact ABA-binding site similar to the one in the canonical Pyrabactin resistance 1/PYR-like/Abscisic acid receptors, with Vmax of 1.19 pmole min{square}1 g{square}1 in the absence of ABA, increasing to 1.58 pmole min{square}1 g{square}1 at 2 nM ABA, and decreasing to 0.75 pmole min{square}1 g{square}1 at 50 nM ABA. These findings are therefore consistent with a direct role of ABA in PDE activity modulations and form a functional link between 3,5-cAMP signaling and K+ flux. Furthermore, we predict that a growing number of such receptor-like proteins that specifically and directly interact with ABA will be discovered thereby uncovering complex and ancient layers of signaling and metabolic regulation.

plant biology↗

bioRxiv2025

Functional genomics and tumor microenvironment analysis reveal prognostic biological subtypes in Mantle cell lymphoma

Mantle cell lymphoma (MCL) is a genetically and clinically heterogeneous B-cell malignancy. We studied two MCL cohorts with differing treatment patterns: one enriched for immunochemotherapy, the other for chemotherapy alone. TP53 alterations were consistently associated with poor prognosis, whereas ATM mutations correlated with improved outcomes following rituximab-based chemotherapy. Based on recurrent genetic events, six clusters were identified and refined into three prognostic groups: high-risk (TP53 mutations and deletions at 17p13.3, 13q14.2, and 19p13.3), intermediate-risk (ATM and epigenetic regulator mutations, or gains at 8q/17q/15q), and low-risk (lacking TP53 alterations, rare ATM mutations without 11q deletions, gains at 3q, deletions at 6q). Transcriptomic analysis revealed enrichment of proliferation, metabolism-promoting gene signatures in high-risk; angiogenesis and NOTCH signaling in intermediate-risk; and proinflammatory-related (i.e., IFN, TNF) in low-risk MCLs. Multi-proteomic spatial profiling using imaging mass cytometry (IMC) demonstrated enrichment of CD8 T cells with high expression of exhaustion markers and dominant population of myeloid cells skewed toward an M2-like phenotype. Compared to ATM-perturbed tumors, TP53-perturbed tumors exhibited enriched SOX11 tumor cells and enhanced tumor-immune cell interactions. Functional analysis revealed that p53 represses BCR signaling through PTPN6 activation. Collectively, these findings highlight distinct molecular and immune landscapes and reveal therapeutic vulnerabilities in high-risk TP53-altered MCL.

cancer biology↗

bioRxiv2025

DeepPGDB: A Novel Paradigm for AI-Guided Interactive Plant Genomic Database

DeepPGDB (https://www.deeppgdb.chat) is the first AI-driven plant genomics database designed to lower technical barriers in multi-omics research by enabling natural language-based data access and analysis. Integrating over 50 high-quality plant genomes, DeepPGDB combines fine-tuned large language models (LLMs) with prompt engineering to interpret user queries, generate standardized bioinformatics commands, and retrieve or visualize genomic data. Key functionalities include sequence retrieval, BLAST alignment, gene localization, expression profiling, and population genetics analysis, all presented via an intuitive conversational interface. A summarization module further enhances biological reasoning, inferring insights such as haplotype differentiation or protein properties. Benchmarking revealed that Deepseek-r1:14b optimized for short pre-prompts delivers high accuracy and speed. By bridging computational and biological expertise, DeepPGDB democratizes genomic research, fostering interdisciplinary collaboration and accelerating discoveries in agriculture and biotechnology.

bioinformatics↗

bioRxiv2025

SPTnet: a deep learning framework for end-to-end single-particle tracking and motion dynamics analysis

Single-particle tracking (SPT) provides high-resolution spatial-temporal information on biomolecule dynamics. However, localization inaccuracies, limited track lengths, heterogeneous fluorescence backgrounds, and potential molecular motion blur pose significant challenges that hinder the accurate extraction of movement trajectories and their underlying motion behavior. The conventional SPT pipeline struggles to comprehensively address detection, localization, linkage, and motion parameter inference simultaneously, resulting in information loss during sequential processing. To overcome these challenges, we propose SPTnet, an end-to-end deep learning framework that leverages a Transformer-based architecture to optimize trajectory and motion parameter estimations in parallel through a global loss. SPTnet bypasses traditional SPT processes, directly inferring molecular trajectories and motion parameters from fluorescence microscopy videos with a precision approaching the statistical information limit. Our results demonstrate that SPTnet outperforms conventional methods under commonly encountered but challenging conditions such as short trajectories, low signal-to-noise ratio (SNR), heterogeneous backgrounds, motion blur, and especially when molecules exhibit non-Brownian behaviors.

biophysics↗

bioRxiv2025

Interferometric Ultra-High Resolution 3D Imaging through Brain Sections

Single-molecule super-resolution microscopy allows pin-pointing individual molecular positions in cells with nanometer precision. However, achieving molecular resolution through tissues is often difficult because of optical scattering and aberrations. We introduced 4Pi single-molecule nanoscopy for brain with in-situ point spread function retrieval through opaque tissue (4Pi-BRAINSPOT), integrating 4Pi single-molecule switching nanoscopy with dynamic in-situ coherent PSF modeling, single-molecule compatible tissue clearing, light-sheet illumination, and a novel quantitative analysis pipeline utilizing the highly accurate 3D molecular coordinates. This approach enables the quantification of protein distribution with sub-15-nm resolution in all three dimensions in complex tissue specimens. We demonstrated 4Pi-BRAINSPOTs capacities in revealing the molecular arrangements in various sub-cellular organelles and resolved the membrane morphology of individual dendritic spines through 50-{micro}m transgenic mouse brain slices. This ultra-high-resolution approach allows us to decipher nanoscale organelle architecture and molecular distribution in both isolated cells and native tissue environments with precision down to a few nanometers.

neuroscience↗

bioRxiv2024

DeepSomatic: Accurate somatic small variant discovery for multiple sequencing technologies

Somatic variant detection is an integral part of cancer genomics analysis. While most methods have focused on short-read sequencing, long-read technologies now offer potential advantages in terms of repeat mapping and variant phasing. We present DeepSomatic, a deep learning method for detecting somatic SNVs and insertions and deletions (indels) from both short-read and long-read data, with modes for whole-genome and exome sequencing, and able to run on tumor-normal, tumor-only, and with FFPE-prepared samples. To help address the dearth of publicly available training and benchmarking data for somatic variant detection, we generated and make openly available a dataset of five matched tumor-normal cell line pairs sequenced with Illumina, PacBio HiFi, and Oxford Nanopore Technologies, along with benchmark variant sets. Across samples and technologies (short-read and long-read), DeepSomatic consistently outperforms existing callers, particularly for indels.

bioinformatics↗

bioRxiv2024

Bilateral integration in somatosensory cortex is controlled by behavioral relevance

Sensory perception naturally requires processing stimuli from both sides of the body. Yet, how neurons bind stimulus features across the hemispheres to create a unified perceptual experience remains unknown. To address this question, we performed large-scale recordings from neurons in both somatosensory cortices (S1) while mice shared information between their hemispheres and discriminated between two categories of bilateral stimuli. When expert mice touched stimuli associated with reward, they moved their whiskers with greater bilateral symmetry. During this period, synchronous spiking and enhanced spike-field coupling emerged between the hemispheres. This coordinated activity was absent in stimulus-matched naive animals, indicating that interhemispheric (IH) binding was controlled by a goal-directed, internal process. In S1 neurons, the addition of ipsilateral touch primarily facilitated the contralateral, principal whisker response. This facilitation primarily emerged for reward-associated stimuli and was lost on trials where expert mice failed to respond. Taken together, these results reveal a novel state-dependent logic underlying bilateral integration in S1, where stimulus binding and facilitation are controlled by behavioral relevance.

neuroscience↗

bioRxiv2024

Brain-wide functional connectome analysis of 40,000 individuals reveals brain networks that show aging effects in older adults

The functional connectome changes with aging. We systematically evaluated aging related alterations in the functional connectome using a whole-brain connectome network analysis in 39,675 participants in UK Biobank project. We used adaptive dense network discovery tools to identify networks directly associated with aging from resting-state fMRI data. We replicated our findings in 499 participants from the Lifespan Human Connectome Project in Aging study. The results consistently revealed two motor-related subnetworks (both permutation test p-values <0.001) that showed a decline in resting-state functional connectivity (rsFC) with increasing age. The first network primarily comprises sensorimotor and dorsal/ventral attention regions from precentral gyrus, postcentral gyrus, superior temporal gyrus, and insular gyrus, while the second network is exclusively composed of basal ganglia regions, namely the caudate, putamen, and globus pallidus. Path analysis indicates that white matter fractional anisotropy mediates 19.6% (p<0.001, 95% CI [7.6% 36.0%]) and 11.5% (p<0.001, 95% CI [6.3% 17.0%]) of the age-related decrease in both networks, respectively. The total volume of white matter hyperintensity mediates 32.1% (p<0.001, 95% CI [16.8% 53.0%]) of the aging-related effect on rsFC in the first subnetwork.

neuroscience↗

bioRxiv2024

Proteolytic Cleavage of the ENaC gamma Subunit: Impact Upon Na+ and K+ Handling

The ENaC gamma subunit is essential for homeostasis of Na+, K+, and body fluid. Dual subunit cleavage before and after a short inhibitory tract allows dissociation of this tract, increasing channel open probability (PO), in vitro. Cleavage proximal to the tract occurs at a furin recognition sequence (143RKRR146 in mouse). Loss of furin-mediated cleavage prevents in vitro activation of the channel by proteolysis at distal sites. We hypothesized that 143RKRR146 mutation to 143QQQQ146 (Q4) in 129/Sv mice would reduce ENaC PO, impair flow-stimulated flux of Na+ (JNa) and K+ (JK) in perfused collecting ducts, reduce colonic amiloride-sensitive short circuit current (ISC), and impair Na+, K+, and body fluid homeostasis. Immunoblot of Q4/Q4 mouse kidney lysates confirmed loss of a band consistent in size with the furin-cleaved proteolytic fragment. However, Q4/Q4 male mice on a low Na+ diet did not exhibit altered ENaC PO or flow-induced JNa, though flow-induced JK modestly decreased. Colonic amiloride-sensitive ISC in Q4/Q4 mice was not altered. Q4/Q4 males, but not females, exhibited mildly impaired fluid volume conservation when challenged with a low Na+ diet. Blood Na+ and K+ were unchanged on a regular, low Na+, or high K+ diet. These findings suggest that biochemical evidence of gamma subunit cleavage should not be used in isolation to evaluate ENaC activity. Further, factors independent of gamma subunit cleavage modulate channel PO and the influence of ENaC on Na+, K+, and fluid volume homeostasis in 129/Sv mice, in vivo.

physiology↗

bioRxiv2023

Wiskott-Aldrich Syndrome Protein Regulates Nucleolar Organization and Function in Innate Immune Response

Wiskott-Aldrich syndrome (WAS) is a primary immunodeficiency disorder caused by the dysfunction of the WAS protein (WASP). Using an isogenic macrophage model derived from genome edited induced pluripotent stem cells we demonstrated that WASP functions in the nucleolus, which plays important roles in immune regulation. The absence of WASP resulted in smaller and misshapen nucleoli, decreased fibrillar center territory, and impaired ribosomal RNA (rRNA) transcription. The nucleolar and rRNA phenotypes were confirmed in WAS patient samples. Furthermore, WASP interacts with nucleolar proteins, including nucleophosmin 1 (NPM1) and fibrillarin (FBL). NPM1 deficiency is known to cause elevated cytokine expression following lipopolysaccharide (LPS) stimulation. Consistently, WASP deficient cells displayed lower levels of NPM1 and a heightened inflammatory cytokine response to LPS, which was rescued by overexpressing NPM1. Together, our research provides novel insights into the critical role of WASP in nucleolar function and the modulation of inflammatory cytokine production.

cell biology↗

bioRxiv2023

Resolving the unsolved: Comprehensive assessment of tandem repeats at scale

Tandem repeat (TR) variation is associated with gene expression changes and over 50 rare monogenic diseases. Recent advances in sequencing have enabled accurate, long reads that can characterize the full-length sequence and methylation profile of TRs. However, despite these advances in sequencing technology, computational methods to fully profile tandem repeats across the genome do not exist. To address this gap, we introduce tools for tandem repeat genotyping (TRGT), visualization and an accompanying TR database. TRGT accurately resolves the length and sequence composition of TR regions in the human genome. Assessing 937,122 TRs, TRGT showed a Mendelian concordance of 99.56%, allowing a single repeat unit difference. In six samples with known repeat expansions, TRGT detected all repeat expansions while also identifying methylation signals, mosaicism, and providing finer resolution of repeat length. Additionally, we release a database with allele sequences and methylation levels for 937,122 TRs across 100 genomes.

genomics↗

bioRxiv2023

Antibody-mediated cell entry of SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters host cells by first engaging its cellular receptor angiotensin converting enzyme 2 (ACE2) to induce conformational changes in the virus-encoded spike protein and fusion between the viral and target cell membranes. We report here that certain monoclonal neutralizing antibodies against distinct epitopic regions of the receptor-binding domain of the spike can replace ACE2 to serve as a receptor and efficiently support membrane fusion and viral infectivity. These receptor-like antibodies can function in the form of a complex of their soluble immunoglobulin G with Fc-gamma receptor I, a chimera of their antigen-binding fragment with the transmembrane domain of ACE2 or a membrane-bound B cell receptor, indicating that ACE2 and its specific interactions with the spike protein are dispensable for SARS-CoV-2 entry. These results suggest that antibody responses against SARS-CoV-2 may expand the viral tropism to otherwise nonpermissive cell types; they have important implications for viral transmission and pathogenesis.

microbiology↗

bioRxiv2022

Modulation of the microhomology-mediated end joining pathway suppresses large deletions and enhances homology-directed repair following CRISPR-Cas9-induced DNA breaks

CRISPR-Cas9, an efficient genome editing tool, has been widely used in research and holds great promise in the clinic. However, large unintended rearrangements of the genome occur frequently after CRISPR-Cas9 editing and their potential risk cannot be ignored. In this study, we detected large deletions (LDs) induced by CRISPR-Cas9 in human embryonic stem cells (hESCs) and found the microhomology end joining (MMEJ) DNA repair pathway plays a predominant role in LD. We genetically targeted PARP1, RPA, POLQ and LIG3, which play critical roles in MMEJ, during CRISPR-Cas9 editing. By analyzing LD events in two independent gene loci, CD9 and PIGA, using flow cytometry and long-read individual molecule sequencing (IDMseq), we showed that knocking down PARP1 and LIG3 does not alter the frequency of Cas9-induced LD, while knocking down or inhibiting POLQ dramatically reduces LD. Knocking down RPA increases LD frequency, and overexpression of RPAs consistently reduces LD frequency. Interestingly, small-molecule inhibition of POLQ and delivery of recombinant RPA proteins also dramatically increase the efficiency of homology-directed repair (HDR). In conclusion, RPA and POLQ play opposite roles in Cas9-induced LD, modulation of POLQ and RPA can reduce LD and improve HDR, thus holding promise for safe and precise genome editing.

molecular biology↗

bioRxiv2022

3rd-ChimeraMiner: A pipeline for integrated analysis of whole genome amplification generated chimeric sequences using long-read sequencing

Multiple displacement amplification (MDA) has become one of the most commonly used method of whole genome amplification (WGA) due to the high processivity, strand displacement capacity and high fidelity of the phi29 DNA polymerase, MDA generate vast amount of DNA with higher molecules weight (up to 100kb) and greater genome coverage. Along with the development of the sequencing platform, it is possible to sequence the MDA-amplified DNA molecules with over 20kb by long-read sequencing. However, one of the challenges is the formation of chimeras, which exist in all MDA products, and seriously interfere with the downstream analysis of the long-read sequencing data of MDA-amplified DNA. In this study, we constructed 3rd-ChimeraMiner, a chimera detection pipeline for analyzing the long-read sequencing of MDA products, recognizing chimeras, and integrating chimeras into the downstream analysis. Five sequencing data of MDA with different magnification fold were analyzed in here, the proportions of chimeras are much higher than that of next-generation sequencing reads and increase with the increase of magnification folds, ranging from 42% to over 76%. After comparing, 99.92% of recognized chimeras have been demonstrated not to exist in original genomes. After detecting chimeras by 3rd-ChimeraMiner, the full-length mapping ratio increased, means more PacBio data could be used in downstream analysis, and mean 97.77% inversions were removed after transferred chimeras into normal reads. 3rd-ChimeraMiner revealed efficiency and accuracy in discovering chimeras from long-read sequencing data of MDA, and is promising to be widely used in single-cell sequencing.

bioinformatics↗

bioRxiv2022

Three amphioxus reference genomes reveal gene and chromosome evolution of chordates

The slow-evolving invertebrate amphioxus has an irreplaceable role in advancing our understanding into the vertebrate origin and innovations. Here we resolve the nearly complete chromosomal genomes of three amphioxus species, one of which best recapitulates the 17 chordate ancestor linkage groups. We reconstruct the fusions, retention or rearrangements between descendants of whole genome duplications (WGDs), which gave rise to the extant microchromosomes likely existed in the vertebrate ancestor. Similar to vertebrates, the amphioxus genome gradually establishes its 3D chromatin architecture at the onset of zygotic activation, and forms two topologically associated domains at the Hox gene cluster. We find that all three amphioxus species have ZW sex chromosomes with little sequence differentiation, and their putative sex-determining regions are nonhomologous to each other. Our results illuminate the unappreciated interspecific diversity and developmental dynamics of amphioxus genomes, and provide high-quality references for understanding the mechanisms of chordate functional genome evolution.

evolutionary biology↗

bioRxiv2020

Single-cell Individual Complete mtDNA Sequencing Uncovers Hidden Mitochondrial Heterogeneity in Human and Mouse Oocytes

The ontogeny and dynamics of mtDNA heteroplasmy remain unclear due to limitations of current mtDNA sequencing methods. We developed individual Mitochondrial Genome sequencing (iMiGseq) of full-length mtDNA for ultra-sensitive variant detection, complete haplotyping, and unbiased evaluation of heteroplasmy levels, all at the individual mtDNA molecule level. iMiGseq uncovers unappreciated levels of heteroplasmic variants in single healthy human oocytes well below the current 1% detection limit, of which numerous variants are detrimental and could contribute to late-onset mitochondrial disease and cancer. Extreme mtDNA heterogeneity among oocytes of the same mouse female, and a strong selection against deleterious mutations in human oocytes are observed. iMiGseq could comprehensively characterize and haplotype single-nucleotide and structural variants of mtDNA and their genetic linkage in NARP/Leigh syndrome patient-derived cells. Therefore, iMiGseq could not only elucidate the mitochondrial etiology of diseases, but also help diagnose and prevent mitochondrial diseases with unprecedented precision.

genomics↗

bioRxiv2020

A Tumbling Magnetic Microrobot System for Biomedical Applications

A microrobot system comprised of an untethered tumbling magnetic microrobot, a two degree of freedom rotating permanent magnet, and an ultrasound imaging system has been developed for in vitro and in vivo biomedical applications. The microrobot tumbles end-over-end in a net forward motion due to applied magnetic torque from the rotating magnet. By turning the rotational axis of the magnet, two-dimensional directional control is possible and the microrobot was steered along various trajectories, including a circular path and P-shaped path. The microrobot is capable of moving over the unstructured terrain within a murine colon in in vitro, in situ, and in vivo conditions, as well as a porcine colon in ex vivo conditions. High frequency ultrasound imaging allows for real-time determination of the microrobots position while it is optically occluded by animal tissue. When coated with a fluorescein payload, the microrobot was shown to release the majority of the payload over a one hour time period in phosphate-buffered saline. Cytotoxicity tests demonstrated that the microrobots constituent materials, SU-8 and polydimethylsiloxane (PDMS), did not show a statistically significant difference in toxicity to murine fibroblasts from the negative control, even when the materials were doped with magnetic neodymium microparticles. The microrobot systems capabilities make it promising for targeted drug delivery and other in vivo biomedical applications.

bioengineering↗