Biology subjects

Xing, Q.

Publications and source records attributed to Xing, Q..

10 recordsLinked to original sources

bioRxiv2026

Steller: a high-resolution platform for spatial clonal tracing of mammalian brain development

Resolving both lineage history and spatial position at single-cell resolution is essential for understanding how tissue assemble, yet simultaneously interrogation of both dimensions remains technically challenging. Here, we present Steller (Spatio-temporal cell lineage tracker), an integrated experimental and computational framework that overcomes the sensitivity bottleneck limiting lineage barcode detection in high-resolution spatial transcriptomics (ST). By co-depositing capture probes alongside conventional poly(T) oligonucleotides on high-density spatial arrays, Steller achieves targeted enrichment of lineage barcodes at spatial single cell resolution. Applied to clonally labeled embryonic day 12.5 (E12.5) mouse forebrain development harvested at postnatal day 4 (P4), Steller increased the proportion of barcode-detectable cells and recovered higher clonal diversity compared with poly(T) chip. Leveraging this enhanced sensitivity, we resolved distinct spatial clonal architectures across three forebrain regions: horizontal or radial-to-horizontal transitions in hippocampal pyramidal neurons, dorsoventrally restricted yet multi-nuclei spread in thalamus, and fate-restricted spiny projection neuron lineages. Steller establishes a generalizable strategy for lineage-enhanced spatial profiling compatible with existing high-resolution spatial transcriptomics platforms and adaptable to diverse biologic process, providing a framewrok for investigating lineage-dependent tissue organization. HighlightsO_LISteller integrates targeted lineage-barcode enrichment with high-resolution spatial transcriptomics C_LIO_LISteller substantially improves clonal detection sensitivity at single-cell resolution C_LIO_LISteller reveals region-specific spatial clonal architectures across the developing mouse forebrain C_LI

Developmental Biology↗

bioRxiv2025

H3K4me1 directs H3K36me2 and H3K36me3 deposition in land plants

Monomethylation of histone H3 lysine 4 (H3K4me1) marks enhancers in mammals. However, the function of H3K4me1 in plants remains largely unclear. Here, we analyzed the genome-wide distribution of H3K4me1 in diverse species across evolution, revealing a distinctive H3K4me1 distribution pattern in land plants. To explore the function of H3K4me1 in plants, we identified an H3K4me1-specific reader protein, Early heading date 3 (Ehd3), and solved the structure of Ehd3 in complex with the H3K4me1 peptide, revealing a unique binding module differing from the previously reported PHD finger proteins. We further identified an Ehd3-binding protein, SET domain group 724 (SDG724), and the deletion of either Ehd3 or SDG724 caused similar defects in plant phenotype and changes in transcriptome and epigenome profiles. Both Ehd3 and SDG724 are enriched at chromatin regions marked by H3K4me1 but not H3K4me2 or H3K4me3. Ehd3 activates the H3K36 methyltransferase SDG724, and H3K36me2/me3 are colocalized with H3K4me1 in the genomes of land plants. Collectively, our results reveal that H3K4me1 directs the establishment of H3K36me2 and H3K36me3 in land plants.

molecular biology↗

bioRxiv2025

The bivalent epigenetic regulator ULTRAPETALA1 promotes the Arabidopsis floral transition via recruitment of Polycomb histone methyltransferases for H3K27me3 deposition at the FLC locus

Floral induction is a major transition during the plant life cycle that contributes to reproductive fitness in annual and perennial plants. Flowering occurs in response to multiple environmental and endogenous cues. In Arabidopsis thaliana, many of these cues converge on the regulation of the FLOWERING LOCUS C (FLC) gene, which encodes a MADS domain transcription factor that functions as the main floral repressor. Here we demonstrate that the bivalent epigenetic regulator ULTRAPETALA1 (ULT1) is both necessary and sufficient to promote flowering. We identify ULT1 as a novel component of the autonomous pathway (AP) and show that it accelerates flowering by directly repressing FLC transcription. We demonstrate that ULT1 physically associates with the SWINGER (SWN) and CURLY LEAF (CLF) histone methyltransferase components of Polycomb Repressive Complex 2 (PRC2) to regulate FLC transcription by altering the accumulation of H3K27me3 marks. Our data indicate that ULT1 promotes the floral transition by interacting with SWN and CLF to recruit PRC2 to the FLC locus to deposit repressive histone methylation and reduce transcription of this key floral repressor.

plant biology↗

bioRxiv2023

In vivo Ontogeny of human forebrain neural progenitor cell grafts in adult rats: an immunohistological study

A thorough understanding of the cell behaviors of the human neural grafts is fundamental to exploit them to achieve cell therapy for recovering brain functions. Here by using immunohistological staining, we trace the cell fate of the intrastriatal human neural progenitor cell (NPC) grafts up to 9 months in adult rats, with multiple examining time points to provide a unified working time frame for future transplantation study. Lots of Nestin+/Sox2+ human cells continuously migrate along the white matter tracts into distal brain parenchyma even long time after transplantation, providing a potential for curing diffuse brain damage. Further analysis reveals a significant heterogeneity of the long-term sustained neural stem cells (NSC)/NPCs that progressing throughout different stages, mimicking the neural development of human forebrain. More importantly, the initial GFAP expression in human grafts marks the NSC progression instead of terminal astrocyte differentiation. The distally migrating human cells continuously show the capability to produce new neurons, albeit at a low efficiency in the intact brain. Further investigations in neural disease models are needed. Such study would benefit neural cell therapy with regarding to the optimization of the transplantation strategy and choosing of acting mode by neural grafts (e.g. via cell replacement or ex vivo gene therapy).

cell biology↗

bioRxiv2023

An ULK1/2-PXN mechanotransduction complex suppresses breast cancer cell migration

The remodeling and stiffening of the extracellular matrix (ECM) associated with breast cancers is a well-recognized modulator of disease progression. However, how changes in the mechanical properties of the ECM are converted into biochemical signals that direct tumor cell migration and metastasis remains poorly characterized. Here, we describe a new role for the autophagy-inducing serine/threonine kinases ULK1 and ULK2 in mechanotransduction. We demonstrate that ULK1/2 activity inhibits the assembly of actin stress fibers and focal adhesions (FAs), and as a consequence impedes cell contraction and migration. Mechanistically, we identify PXN/paxillin, a key component of the mechanotransducing machinery, as a direct binding partner and substrate of ULK1/2. ULK-mediated phosphorylation of PXN at S32 and S119 weakens homotypic interactions and liquid-liquid phase separation of PXN, impairing FA assembly, which in turn impedes the mechanotransduction of breast cancer cells. ULK1/2 and the well characterized PXN regulator, FAK/Src, have opposing functions on mechanotransduction and compete for phosphorylation of adjacent serine and tyrosine residues. Thus, our study reveals ULK1/2 as important regulators of PXN-dependent mechanotransduction. HighlightsO_LIULK1/2 interact with PXN and phosphorylate PXN at S32 and S119 in response to mechanical stimuli C_LIO_LIULK1/2-mediated phosphorylation of PXN regulates mechanotransduction and migration of breast cancer cells C_LIO_LIULK1/2 modulate the biomaterial properties of focal adhesions through PXN phosphorylation C_LIO_LIULK1/2 and FAK/Src act antagonistically in mechanotransduction through competitive phosphorylation of PXN C_LI

cell biology↗

bioRxiv2022

PXN/Paxillin Phase Separation Promotes Focal Adhesion Assembly and Integrin Signaling

Focal adhesions (FAs) are transmembrane protein assemblies mediating cell-matrix connection. Tools to manipulate the compositionally intricate and dynamic FAs are currently limited, rendering many fundamental hypotheses untestable. Although protein liquid-liquid phase separation (LLPS) has been tied to the organization and dynamics of FAs, the underlying mechanisms remain unclear. Here, we experimentally tune the LLPS of PXN/Paxillin, an essential scaffold protein of FAs, by utilizing light-inducible Cry2 system. In addition to nucleating FA components, light-triggered PXN LLPS potently activates integrin signaling and subsequently accelerates cell spreading. PXN favors homotypic interaction-driven LLPS in vitro. In cells, PXN condensates are associated with plasma membrane, and modulated by actomyosin contraction and client proteins of FAs. Interestingly, non-specific weak inter-molecular interactions, together with specific molecular interactions, underlie the multicomponent condensation of PXN, and are efficient to promote FA assembly and integrin signaling. Thus, our data establish an active role of PXN phase transition into a condensed membrane-associated compartment in promoting assembly/maturation of FAs.

cell biology↗

bioRxiv2021

Assembly status transition offers an avenue for activity modulation of a supramolecular enzyme

Nature has evolved many supramolecular proteins assembled in certain, sometimes even seemingly oversophisticated, morphological manners. The rationale behind such evolutionary efforts is often poorly understood. Here we provide atomic-resolution insights into how the dynamic building of a structurally complex enzyme with higher-order symmetry offers amenability to intricate allosteric regulation. We have established the functional coupling between enzymatic activity and protein morphological states of glutamine synthetase (GS), an old multi-subunit enzyme essential for cellular nitrogen metabolism. Cryo-EM structure determination of GS in both the catalytically active and inactive assembly states allows us to reveal an unanticipated self-assembly-induced dynamics-driven allosteric paradigm, in which the remote interactions between two subcomplex entities significantly rigidify the otherwise structurally fluctuating active sites, thereby regulating activity. We further show in vivo evidences that how the enzyme morphology transitions could be modulated by cellular factors on demand. Collectively, our data present an example of how assembly status transition offers an avenue for allosteric modulation, and sharpens our mechanistic understanding of allostery, dynamics, cooperativity, and other complex functional and regulatory properties of supramolecular enzymes.

biochemistry↗

bioRxiv2019

Defining Essential Enhancer for Pluripotent stem cells using Features Oriented CRISPR-Cas9 Screen

Cis Regulatory Elements (CREs) regulate the expression of the genes in their genomic neighborhoods and influence cellular processes such as cell-fate maintenance and differentiation. To date, there remain major gaps in the functional characterization of CREs and the identification of its target genes in the cellular native environment. In this study, we performed a Features Oriented CRISPR Utilized Systematic (FOCUS) screen of OCT4-bound CREs using CRISPR/Cas9 to identify functional enhancers important for pluripotency maintenance in mouse ES cells. From the initial 235 candidates tested, 16 CREs were identified to be essential stem cell enhancers. Using RNA-seq and genomic 4C-seq, we further uncovered a complex network of candidate CREs and their downstream target genes, which supports the growth and self-renewal of mESCs. Notably, an essential enhancer, CRE111, and its target, Lrrc31, form the important switch to modulate the LIF-JAK1-STAT3 signaling pathway.

genomics↗

bioRxiv2019

Diversification of Reprogramming Trajectories Revealed by Parallel Single-cell Transcriptome and Chromatin Accessibility Sequencing

To unravel the mechanism of human cellular reprogramming process at single-cell resolution, we performed parallel scRNA-Seq and scATAC-Seq analysis. Our analysis reveals that the cells undergoing reprogramming proceed in an asynchronous trajectory and diversify into heterogeneous sub-populations. BDD2-C8 fluorescent probe staining and negative staining for CD13, CD44 and CD201 markers, could enrich for the GDF3+ early reprogrammed cells. Combinatory usage of the surface markers enables the fine segregation of the early-intermediate cells with diverse reprogramming propensities. scATAC-Seq analysis further uncovered the genomic partitions and transcription factors responsible for the regulatory phasing of reprogramming process. Binary choice between a FOSL1 or a TEAD4-centric regulatory network determines the outcome of a successful reprogramming. Altogether, our study illuminates the multitude of diverse routes transversed by individual reprogramming cells and presents an integrative roadmap for identifying the mechanistic part-list of the reprogramming machinery.

genomics↗

bioRxiv2019

Global analysis of epigenetic heterogeneity identifies divergent drivers of esophageal squamous cell carcinoma

Epigenetic landscapes can shape physiologic and disease phenotypes. We used integrative, high resolution multi-omics methods to characterize the oncogenic drivers of esophageal squamous cell carcinoma (ESCC). We found 98% of CpGs are hypomethylated across the ESCC genome and two-thirds occur in long non-coding (lnc)RNA regions. DNA methylation and epigenetic heterogeneity both coincide with chromosomal topological alterations. Gene body methylation, polycomb repressive complex occupancy, and CTCF binding sites associate with cancer-specific gene regulation. Epigenetically-mediated activation of non-canonical WNT signaling and the lncRNA ESCCAL-1 were validated as potential ESCC driver alterations. Gene-specific cancer driver roles of epigenetic alterations and heterogeneity are identified.

cell biology↗