Biology subjects

Ma, J.

Publications and source records attributed to Ma, J..

At least 181 records · Page 10Linked to original sources

bioRxiv2024

MRGM: An enhanced catalog of mouse gut microbial genomes substantially broadening taxonomic and functional landscapes

Mouse gut microbiome research is pivotal for understanding the human gut microbiome, providing insights into disease modeling, host-microbe interactions, and the dietary influence on the gut microbiome. To enhance the translational value of mouse gut microbiome studies, we need detailed and high-quality catalogs of mouse gut microbial genomes. We introduce the Mouse Reference Gut Microbiome (MRGM), a comprehensive catalog with 42,245 non-redundant mouse gut bacterial genomes across 1,524 species. MRGM marks a 40% increase in the known taxonomic diversity of mouse gut microbes, capturing previously underrepresented lineages through refined genome quality assessment techniques. MRGM not only broadens the taxonomic landscape but also enriches the functional landscape of the mouse gut microbiome. Using deep learning, we have elevated the Gene Ontology annotation rate for mouse gut microbial proteins from 3.2% with orthology to 60%, marking an over 18-fold increase. MRGM supports both DNA- and marker-based taxonomic profiling by providing custom databases, surpassing previous catalogs in performance. Finally, taxonomic and functional comparisons between human and mouse gut microbiota reveal diet-driven divergences in their taxonomic composition and functional enrichment. Overall, our study highlights the value of high-quality microbial genome catalogs in advancing our understanding of the co-evolution between gut microbes and their host.

microbiology↗

bioRxiv2024

MLCK/MLCP regulates mammalian axon regeneration via the redistribution of the growth cone F-actin

Axon regrowth is a key determinant of the restoration of the biological function of the nervous system after trauma. However, mature mammalian neurons have limited capacity for axon regeneration. We have previously demonstrated that neuronal axon growth both in the central and the peripheral nervous systems is markedly enhanced when non-muscle myosin II (NMII) is inhibited with blebbistatin. The activity of NMII is primarily regulated by MLCK and MLCP via the phosphorylation and dephosphorylation of its light chain, respectively; however, the functional roles of MLCK and MLCP in mammalian axonal regeneration remain unknown. In the present study, we provide strong evidence that the inhibition of MLCK activity significantly blocks axon regeneration in mice. Conversely, the inhibition of MLCP promotes axon regrowth of both the peripheral and central nervous system. Our findings further indicate that the MLCK/MLCP regulates axon regeneration and redistributes the growth cone F-actin, and this result suggests that direct regulation of the growth cone machinery is a potential strategy to promote axon regeneration.

physiology↗

bioRxiv2024

OPUS-BFactor: Predicting protein B-factor with sequence and structure information

Protein B-factor, also known as the Debye-Waller factor, measures the fluctuation of an atom around its average position. It serves as a crucial indicator of protein flexibility and dynamics. However, accurately predicting the B-factor of C atoms remains challenging. In this work, we introduce OPUS-BFactor, a tool for predicting the normalized protein B-factor. OPUS-BFactor operates in two modes: the first mode, OPUS-BFactor-seq, uses sequence information as input, allowing predictions based solely on protein sequence; the second mode, OPUS-BFactor-struct, uses structural information, requiring the 3D structure of the target protein. Evaluation on three test sets, including recently released targets from CAMEO and CASP15, demonstrates that OPUS-BFactor significantly outperforms other B-factor prediction methods. Therefore, OPUS-BFactor is a valuable tool for predicting protein properties related to the B-factor, such as flexibility, thermal stability, and region activity.

bioinformatics↗

bioRxiv2024

Deterministic processes played more important roles than stochastic processes in driving community assembly of ectomycorrhizal fungal associated with Pinus tabuliformis - an endemic Pinaceae species in China

Pinus tabuliformis represents a typical and essential woody ectomycorrhizae (EM) host plant growing in North China. EM fungi contribute to the host healthy and the stability of the forest ecosystem. However, EM fungal community associated with this tree is less documented. We examined EM fungal diversity and composition of P. tabuliformis from three sites in Inner Mongolia, China by using Illumina MiSeq sequencing on the rDNA ITS2 region. Our results showed that a total of 105 EM fungal operational taxonomic units (OTUs) were identified from 15 composite root samples, and the dominant lineages were /suillus-rhizopogon, /tomentella-thelephora, /tricholoma, /amphinema-tylospora, /wilcoxina, /inocybe and /Sebacina. A high proportion of unique EM fungal OTUs were detected and some abundant OTUs preferred to exist in specific sites. EM fungal communities were significantly different among the sites, with soil, climatic and spatial variables being responsible for the community variations. The EM fungal community assembly was mainly governed by deterministic processes. These findings suggest that this endemic Pinaceae species in China also harbored a rich and distinctive EM fungal community and deterministic processes played more important roles than stochastic in shaping the symbiotic fungal community. Our study improves our understanding of EM fungal diversity and community structure from the perspective of a single host plant that has not been investigated exclusively before.

ecology↗

bioRxiv2024

Fat body-derived cytokine Upd2 controls disciplined migration of tracheal stem cells in Drosophila

Coordinated activation and directional migration of adult stem cells are essential for maintaining tissue homeostasis. Drosophila tracheal progenitors are adult stem cells that migrate posteriorly along the dorsal trunk to replenish degenerating branches that disperse the FGF mitogen. However, it is currently unknown how the overall anterior-to-posterior directionality of such migration is controlled. Here we show that individual progenitor cells migrate together in a concerted, disciplined manner, a behavior that is dependent on the neighboring fat body. We identify the fat body-derived cytokine, Upd2, in targeting and inducing JAK/STAT signaling in tracheal progenitors to maintain their directional migration. Perturbation of either Upd2 production in fat body or JAK/STAT signaling in trachea causes aberrant bidirectional migration of tracheal progenitors. We show that JAK/STAT signaling promotes the expression of genes involved in planar cell polarity leading to asymmetric localization of Fat in progenitor cells. We provide evidence that Upd2 transport requires Rab5- and Rab7-mediated endocytic sorting and Lbm-dependent vesicle trafficking. Our study thus uncovers an inter-organ communication in the control of disciplined migration of tracheal progenitor cells, a process that requires vesicular trafficking of fat body-derived cytokine Upd2 and JAK/STAT signaling-mediated activation of PCP genes.

developmental biology↗

bioRxiv2024

OPUS-TOMO: Deep Learning Framework for Structural Heterogeneity Analysis in Cryo-electron Tomography

Structural heterogeneity in biomolecules, arising from compositional and conformational variability, poses a major challenge for structure determination by cryo-electron tomography (cryo-ET). Here, we introduce OPUS-TOMO, a deep learning framework for resolving multiscale structural heterogeneity across the cryo-ET workflow. Our approach employs a convolutional encoder-decoder architecture and a rigid-body dynamics model to encode subtomograms into two separate low-dimensional latent spaces, realizing hierarchical modelling of compositional diversity and conformational dynamics. OPUS-TOMO adeptly resolved specie-level heterogeneity in template matching results and enabled sub-nanometer reconstructions for both Chlamydomonas reinhardtii ATP synthase dimer and Schizosaccharomyces pombe 80S ribosome, with an improvement of resolution up to 3 [A] compared to expert-annotated datasets. OPUS-TOMO also resolved in situ dynamics for these biomolecules by reconstructing functionally relevant structural continua. The software is available at https://github.com/alncat/opusTOMO.

molecular biology↗

bioRxiv2024

Combining Scalable Organ Chip Platform with Deep Learning-Based Imaging Analysis for Cancer Therapeutic Screening

Functional precision oncology represents an emerging approach to genomic approaches by testing treatment options directly on patient-derived models. Current assays, including the use of patient-derived xenograft (PDX) and patient-derived organoid (PDOs), faces major barriers in clinical use due to technical challenges, such as standardization, cost, assay time, scalability, and faithful mimicry of patient tumor microenvironment (TME). Here, we introduce an Organ Chip (OC) device constructed entirely from thermoplastic materials, free of porous membrane or other barrier structures, and optimized for high-content imaging (HCI). This automation-compatible device supports tissue-specific extracellular matrices and coculture for a wide spectrum of organ and disease types, including the TME. As a proof-of-concept, we demonstrate the growth of pancreatic, lung, and colon cancer cell lines and primary lung cancer cells and the testing of cancer drugs in these models. HCI-based phenotypic profiling enabled accurate quantification of drug response, with better performance than traditional biochemical assays. Moreover, we developed a deep-learning method for assessing drug responses using bright field images. The integration of a low-cost, scalable, and faithful OC models with automatic high-content image analysis represents a significant stride towards functional precision oncology and cancer drug discovery.

bioengineering↗

bioRxiv2024

Horizontally acquired CSP genes contribute to wheat adaptation and improvement

Although horizontal gene transfer (HGT) often facilitates environmental adaptation of recipient organisms, whether and how they might affect crop evolution and domestication is unclear. Here we show that three genes encoding cold shock proteins (CSPs) were transferred from bacteria to the last common ancestor of Triticeae, a tribe of the grass family that includes several major staple crops such as wheat, barley, and rye. The acquired CSP genes in wheat (TaCSPs) are functionally conserved with their bacterial homologs by encoding a nucleic acid binding protein. Experimental evidence indicates that TaCSP genes positively regulate drought response and improve photosynthetic efficiency under water deficit conditions, by directly targeting a type 1 metallothionein gene to increase ROS scavenging, which in turn contributed to the geographic expansion of wheat. We identified an elite CSP haplotype in Aegilops-tauschii, introduction of which to wheat significantly increased drought tolerance, photosynthetic efficiency and grain yields. These findings not only provide major insights into the role of HGT in crop adaptation and domestication, but also demonstrate that novel microbial genes introduced through HGT offer a stable and naturally optimized resource for transgenic crop breeding and improvement.

plant biology↗

bioRxiv2024

Determinants of de novo mutations in extended pedigrees of 43 dog breeds

Intensive breeding of dogs has had dramatic effects on genetic variants underlying phenotypes. To investigate whether this also affected mutation rates, we deep-sequenced pedigrees from 43 different dog breeds representing 404 trios. We find that the mutation rate is remarkably stable across breeds and is predominantly influenced by variation in parental ages. The effect of paternal age per year on mutation rates is approximately 1.5 times greater in dogs than humans, suggesting that the elevated yearly mutation rate in dogs is only partially attributed to earlier reproduction. While there is no significant effect of breeds on the overall mutation rate, larger breeds accumulate proportionally more mutations earlier in development than small breeds. Interestingly, we find a 2.6 times greater mutation rate in CG Islands (CGIs) compared to the remaining genome in dogs, unlike humans, where there is no difference. Our estimated rate of mutation by recombination in dogs is more than 10 times larger than estimates in humans. We ascribe these to the fact that canids have lost PRDM9-directed recombination and draw away recombination from CGIs. In conclusion, our study sheds light on stability of mutation processes and disparities in mutation accumulation rates reflecting the influence of differences in growth patterns among breeds, and the impact of PRDM9 gene loss on the de novo mutations of canids.

evolutionary biology↗

bioRxiv2024

Parallel Analyses by Mass Spectrometry (MS) and Reverse Phase Protein Array (RPPA) Reveal Complementary Proteomic Profiles in Triple-Negative Breast Cancer (TNBC) Patient Tissues and Cell Cultures

High-plex proteomic technologies have made substantial contributions to mechanism studies and biomarker discovery in complex diseases, particularly cancer. Despite technological advancements, inherent limitations in individual proteomic approaches persist, impeding the achievement of comprehensive quantitative insights into the proteome. In this study, we employed two widely used proteomic technologies, Mass Spectrometry (MS) and Reverse Phase Protein Array (RPPA) to analyze identical samples, aiming to systematically assess the outcomes and performance of the different technologies. Additionally, we sought to establish an integrated workflow by combining these two proteomic approaches to augment the coverage of protein targets for discovery purposes. We used fresh frozen tissue samples from triple-negative breast cancer (TNBC) and cell line samples to evaluate both technologies and implement this dual-proteomic strategy. Using a single-step protein denaturation and extraction protocol, protein samples were subjected to reverse phase chromatography (LC) followed by electrospray ionization (ESI)-mediated MS/MS for proteomic profiling. Concurrently, identical sample aliquots were analyzed by RPPA for profiling of over 300 proteins and phosphoproteins that are in key signaling pathways or druggable targets in cancer. Both proteomic methods demonstrated the expected ability to differentiate samples by groups, revealing distinct proteomic patterns under various experimental conditions, albeit with minimal overlap in identified targets. Mechanism-based analysis uncovered divergent biological processes identified with the two proteomic technologies, capitalizing on their complementary exploratory potential.

cancer biology↗

bioRxiv2024

P-cadherin mechanoactivates tumor- mesothelium metabolic coupling to promote ovarian cancer metastasis

Peritoneal metastasis exacerbates the prognosis of ovarian cancer patients. Adhesion of cancer cells to mesothelium is a rate-limiting prerequisite for this process. How metastatic cells sense and respond to the dynamic biomechanical microenvironment at the mesothelial niche to initiate metastatic lesions remains unclear. Here, the study demonstrates that highly metastatic (HM), but not non-metastatic (NM) ovarian cancer cells, selectively activate the peritoneal mesothelium. Atomic force microscopy reveals that HM cells exert increased adhesive force on mesothelial cells via P-cadherin, a cell-cell adhesion molecule abundant in late-stage tumors. Transcriptomic and molecular analyses show that mechanical induction of P-cadherin enhances lipogenic gene expression and lipid content in HM cells by SREBP1. P-cadherin activation does not affect lipogenic activity but induces glycolysis in the interacting mesothelium. Targeted lipidomic analysis reveals that lactate produced by the glycolytic mesothelium facilitates metastatic outgrowth as a direct substrate for de novo lipogenesis. Inhibiting lactate shuttling via nanodelivery of siRNA targeting P-cadherin or MCT1/4 transporters significantly suppresses metastasis in mice. The association of high fatty acid synthase in patient metastatic samples and increased P-cadherin expression supports enhanced de novo lipogenesis in the metastatic niche. The study reveals P-cadherin-mediated mechano-metabolic coupling as a promising target to restrain peritoneal metastasis.

cancer biology↗

bioRxiv2024

Genome sequencing of 'Fuji' apple clonal varieties reveals evolutionary history and genetic mechanism of the spur-type morphology

Somatic variations arising during asexual reproduction can lead to the emergence of bud sports exhibiting advantageous traits, forming the basis for bud sport breeding in perennial plants. Here, we report a near-complete, fully phased genome assembly of Fuji apple, enabling comprehensive identification of somatic variants across 74 clonally propagated Fuji varieties. Phylogenetic analysis of Fuji sport varieties indicates that the emergence of spur-type and early maturation traits results from multiple independent formation events. A number of putative functional somatic variants are identified, including one spur-type specific deletion located in the promoter of the TCP transcription factor gene MdTCP11. DNA methylation level of the deletion-associated miniature inverted-repeat transposable element is lower in the spur-type varieties compared to the standard-type varieties, while the expression of MdTCP11 is significantly higher. Overexpression of MdTCP11 in apple decreases the plant height, highlighting its important role in the development of spur-type apple varieties. This study sheds light on the 80-year cloning history of Fuji and provides valuable candidate causative mutations for apple breeding.

plant biology↗

bioRxiv2024

Modeling Repertoire Behavior within the Energy-Based Framework: A Study on Cell Proliferation and Somatic Hypermutation during the Adaptive Immune Response

Monitoring and describing the adaptive immune repertoire(IR) for disease detection and diagnosis is essential in healthcare research. Many phenomenon have been observed to generalize the static property of IR, but the mathematical description of the formation and dynamic changes of IR still lacks research. Here, we present a mathematical and physical model to interpret the cell proliferation and somatic hypermutation(SHM) process in IR, difficulties to generate different clones in IR are computed, and IR distance is calculated as the minimum effort required to transform one IR distribution to another. IR distribution and distance can be detected from samples containing 104 cells. The validity of our method is confirmed by the unsupervised clustering of data from mice spleen and clinical PBMC samples including various immune stages and diseases. Our work dynamically characterize and quantify IR process, enabling a macroscopic immunoevaluation by sensitive immune fluctuation detection from minute samples.

biophysics↗

bioRxiv2024

Protease-activated receptor 2 links protease activity with calcium waves during egg activation and blastomere cleavage

Successful initiation of animal development requires activation of the egg immediately prior to fusion of gamete pronucleii. In all taxa, this is initiated by waves of calcium transients which transverse across the egg. Calcium waves also occur at cleavage furrows during later blastula cytokinesis. Calcium is released from the endoplasmic reticulum through activation of 1,4,5-trisphosphate (IP3) receptors. Only a subset of the mechanisms employed to generate IP3 during vertebrate egg activation are defined, with strong evidence that other critical mechanisms exist. Serine proteases have been long implicated in egg activation and fertilisation. Here we report that treatment of zebrafish eggs with serine protease inhibitors leads to defective calcium wave propagation and failed egg activation. We further show that mutation of zebrafish Protease-activated receptor 2a (Par2a) also results in severe disruption of egg activation, leading to failed chorion elevation and ooplasmic segregation. Milder par2a mutants progress further, but then show abnormal blastomere cleavage. We observed that par2a mutants show decreased amplitude and duration of calcium transients. Restoring Ca++ or direct injection of IP3 ligand rescues egg activation aborted by either serine protease inhibitor treatment or by mutation of Par2a. We thus show that serine protease activity is a critical regulator of IP3 and subsequent calcium wave amplification during zebrafish egg activation, and link this to intracellular calcium release via the protease receptor, Par2a. This constitutes a novel signalling pathway critical for successful fertilisation. Significance StatementBoth sperm and egg must undergo a series of important steps to become competent for successful fertilisation. Defining these steps is central to our understanding of reproductive biology and our ability to improve fertility treatments. As the process of gamete maturation and fertilisation has highly conserved principles across the animal kingdom, there are also important implications for aqua- and agriculture. One of the first signalling events of your life leads to the release of bursts of calcium in the egg. We know the importance of this for fertilisation but have only a partial picture of how this occurs. Our work here, using fish genetics, identifies a new signalling pathway regulating these first important flashes of calcium in the egg.

developmental biology↗

bioRxiv2024

Gradual labeling with fluorogenic probes for MINFLUX nanoscopy of densely packed structures

Single-molecule localization in densely packed structures represents a formidable challenge in nanoscopy. Here we develop a gradual labeling method with fluorogenic probes for MINFLUX nanoscopy (GLF-MINFLUX), with which individual proteins in packed structures can be sequential illuminated and quantitatively localized at the nanoscale solely by adjusting probe concentration. With a 1.7-fold localization precision improvement and 2.2-fold faster acquisition, GLF-MINFLUX enables dual-channel nanoscale imaging of densely neuronal microtubules and microfilaments, and three-dimensional quantitative mapping of individual TOM20 proteins in mitochondrial clusters.

biophysics↗

bioRxiv2024

Metabolic enzymes moonlight as selective autophagy receptors to protect plants against viral-induced cellular damage

AbstractRNA viruses co-opt the host endomembrane system and organelles to build replication complexes for infection. How the host responds to these membrane perturbations is poorly understood. Here, we explore the autophagic response of Arabidopsis thaliana to three viruses that hijack different cellular compartments. Autophagy is significantly induced within systemically infected tissues, its disruption rendering plants highly sensitive to infection. Contrary to being an antiviral defense mechanism as previously suggested, quantitative analyses of the viral loads established autophagy as a tolerance pathway. Further analysis of one of these viruses, the Turnip Crinkle Virus (TCV) that hijack mitochondria, showed that despite perturbing mitochondrial integrity, TCV does not trigger a typical mitophagy response. Instead, TCV and Turnip yellow mosaic virus (TYMV) infection activates a distinct selective autophagy mechanism, where oligomeric metabolic enzymes moonlight as selective autophagy receptors and degrade key executors of defense and cell death such as EDS1. Altogether, our study reveals an autophagy-regulated metabolic rheostat that gauges cellular integrity during viral infection and degrades cell death executors to avoid catastrophic amplification of immune signaling.

plant biology↗

bioRxiv2024

Investigation of the mechanism of accelerated biodegradation of Paracoccus-KDSPL-02

Paracoccus-KDSPL-02 can accelerate to degrade penicillin G under light remain poorly understood, largely due to the lack of high-throughput genome engineering tools. Firstly, this study sequenced the genome of Paracoccus-KDSPL-02 and mined the genes that might be involved, and in order to understand in detail whether the expression of the mined genes changed during light. Further, for genes with altering transcriptional levels under light, this study obtained PROKKA_01468 which a photoreceptor protein in Paracoccus-KDSPL-02. In the end, for validating the function of PROKKA_01468, this study knocked down the sequence of the PROKKA_01468 by applying gene editing system, and the knockdown strain showed significant change in the rate of degradation of phenylacetic acid, which is the intermediate product of penicillin G degradation, by light compared with darkness, so that the PROKKA_01468 is the most effective photoreceptor protein in Paracoccus-KDSPL-02. SynopsisThis research elucidates a molecular mechanism capable of accelerating penicillin G degradation in wastewater, with significant implications for environmental science.

bioengineering↗

bioRxiv2024

Sociality in spiders is an evolutionary dead-end

In cooperatively breeding social animals, a few individuals account for all reproduction. In some taxa, sociality is accompanied by a transition from outcrossing to inbreeding, in concert, these traits act to reduce effective population size, potentially rendering transitions to sociality evolutionarily dead-ends. We addressed this hypothesis in a comparative genomic study in spiders, where sociality has evolved independently at least 23 times, but social species are recent and evolutionarily short-lived. We present genomic evidence for the evolutionary dead-end hypothesis in three independent transitions to sociality in the spider genus Stegodyphus. We sequenced, assembled and annotated high-quality, chromosome-level reference genomes from three pairs of closely related social and subsocial Stegodyphus species. Genome sizes range from 2.65 Gb to 3.32 Gb with high synteny, and we identify 10,065 single-copy orthologous genes. We timed the divergence between the social and subsocial species pairs to be from 1.3 to 1.8 million years. Social evolution in spiders involves a shift from outcrossing to inbreeding and from equal to female-biased sex ratio, causing severe reductions in effective population size and decreased efficacy of selection. Based on analyses of purifying selection, we determined whether transitions to sociality co-occurred with divergence. We show that transitions to sociality only had full effect on purifying selection at 119 kya (95CI: 71 kya -169 kya), 260 kya (95CI: 231 ky - 289 kya) and 279 kya (95CI: 230 kya - 332 kya) respectively, and follow remarkably similar convergent trajectories of progressive loss of diversity and shifts to an increasingly female-biased sex ratio. This almost deterministic genomic response to sociality may explain why social spider species do not persist. What causes species extinction is not clear, but could be either selfish meiotic drive that eliminates the production of males, or an inability to retain genome integrity in the face of extremely reduced efficacy of selection.

evolutionary biology↗