Biology subjects

Liao, X.

Publications and source records attributed to Liao, X..

81 records · Page 5Linked to original sources

bioRxiv2019

Knowledge-guided analysis of ‘omics’ data using the KnowEnG cloud platform

We present KnowEnG, a free-to-use computational system for analysis of genomics data sets, designed to accelerate biomedical discovery. It includes tools for popular bioinformatics tasks such as gene prioritization, sample clustering, gene set analysis and expression signature analysis. The system offers knowledge-guided data-mining and machine learning algorithms, where user-provided data are analyzed in light of prior information about genes, aggregated from numerous knowledge-bases and encoded in a massive Knowledge Network. KnowEnG adheres to FAIR principles: its tools are easily portable to diverse computing environments, run on the cloud for scalable and cost-effective execution of compute-intensive and data-intensive algorithms, and are interoperable with other computing platforms. They are made available through multiple access modes including a web-portal, and include specialized visualization modules. We present use cases and re-analysis of published cancer data sets using KnowEnG tools and demonstrate its potential value in democratization of advanced tools for the modern genomics era.

cancer biology↗

bioRxiv2019

Transcriptional Signatures of the Hierarchical Chronnectome Organization in the Human Brain

The chronnectome of the human brain represents the dynamics of functional organization in interacting regions, but its organizational principle and the underlying molecular mechanisms remain unclear. Using task-free fMRI and postmortem gene expression data, we conduct a transcriptome-chronnectome association study to investigate the spatial configurations of dynamic brain networks and their associations with transcriptional signatures. We reveal a spatial layout of network dynamics in the human brain chronnectome that reflects the cortical hierarchy and myelin content spanning from primary to transmodal areas. We further identify the transcriptional signature of this layout, with the top-related genes enriched for the ion channel and mitochondria terms. Moreover, the expression of these genes significantly predicts brain dynamics-behavior coupling. These findings highlight the hierarchical organizing principle and underlying molecular basis of the spatial configurations of dynamic brain networks, thereby contributing to our understanding of the associations among gene expression, network dynamics, and behaviors.

neuroscience↗

bioRxiv2019

Coloring Single Nanoparticle Trajectory on Live Cell Membrane with its Own History: a Presuppositionless Approach

Analyzing single particle trajectories is a prominent issue in understanding complex dynamics such as nanoparticle-cell interactions. Existing methods treat data points as isolated \"atoms\" and use predefined mechanical models to \"frame\" their complicated relationship. Herein, we propose a \"historical evolution\" based model-free strategy. It allows spatiotemporal heterogeneity embedded in a trajectory to self-emerge as consecutive colored segments before any model assumption, provide both an overall picture and local state transitions on the particle movement with minimum information loss, and inspire further model-based investigation. We demonstrate with simulations and experiments that the underlying mechanisms of various time-series and motion states of single nanoparticles on live cell membranes could all be revealed successfully. Since complexity studies at different levels of molecules, particles, cells, human beings, vehicles, and even stars could all be reduced to analyzing spatiotemporal trajectories of \"single particles\", this presuppositionless approach will help fundamental researches on many important systems.\n\nImpact StatementA preprocessing strategy for single particle trajectory analysis is established by providing an intuitive global pattern from \"historical experiences\" of the particle without predefining any mechanical models.

biophysics↗

bioRxiv2019

Comparative analysis of mitochondrial genome between UG93A and UG93B reveal common feature of 5’-end heterogeneity in mitochondrial genes of kenaf

Plant cytoplasmic male sterility (CMS) being maternal phenomenon trait that result from pollen abortion and closely linked with mitochondrial DNA rearrangement in many crops including kenaf. However, the molecular mechanism in kenaf is poorly known. In present work, we described the mitochondrial genome in isonuclear CMS line UG93A and its maintainer line UG93B. Findings of the current study revealed that a total of 398 SNPs and 230 InDels were identified in UG93A mtDNA. Total of 26 SNPs variations and three InDels were identified in the coding region of atp6, indicating its active role in mitochondrial genome re-arrangement. Northern blot analysis showed that the transcripts of atp1, atp4, atp6, cox3 and sdh4 in F1 were consistent with UG93A but different for UG93B. The transcript of atp9 was found similar between UG93B and F1 while different for UG93A, which depict that atp9 may be regulated by nuclear genes in F1 hybrid. The expression of atp9 in UG93A was substantially lower compared with UG93B, suggesting its key role for energy supplying in microspore development of kenaf. Circularized RNA (CR)-RT-PCR revealed that mitochondrial RNAs with heterogeneous 5-ends but uniform 3 - ends are common feature in kenaf mitochondrial genes, and the promoter architecture analysis showed that the promoter sequences in kenaf mitochondrial genome are highly diverged in comparison to those in other plants. Our data highlight that the translation of mitochondrial genes in kenaf is closely associated with heterogeneity of the 5-end of plant mRNA. The present result provides the basic information in understanding the transcription of kenaf mitochondrial genome and can be used as reference in other plants.

molecular biology↗

bioRxiv2019

MATRIEX Imaging: Multi-Area Two-photon Real-time In-vivo Explorer

Two-photon laser scanning microscopy, originally developed since 1990s1, has been widely applied for biomedical research in recent decades, particularly popular among neuroscientists for studying neural functions in vivo2. However, it is typically restricted to one imaging area that is orthogonal to the optical axis. Here, we demonstrate a novel multi-axis optical conjugation method that enables two-photon imaging at single-cell resolution simultaneously in multiple areas at different depths, each of which could have a view diameter of ~200 m and could be largely freely targeted within a zone up to 12-mm diameter. For example, we show simultaneous imaging of neuronal activities in the primary visual cortex (V1), the primary motor cortex (M1) and the hippocampal CA1 region of awake mice. This method can be readily implemented on a single conventional two-photon microscope to enable multi-area exploration of neuronal activities in vivo.

neuroscience↗

bioRxiv2018

Cell rounding causes genomic instability by dissociation of single-stranded DNA-binding proteins

Genomic instability can cause a wide range of diseases, including cancer and cellular senescence, which is also a major challenge in stem cell therapy. However, how a single event can cause extremely high levels of genomic instability remains unclear. Using our developed method, cell in situ electrophoresis (CISE), and models of normal, cancer, and embryonic stem cells, we found that cell rounding as a catastrophic source event ubiquitously observed in vivo and in vitro might lead to large-scale DNA deprotection, genomic instability, chromosomal shattering, cell heterogeneity, and senescent crisis by dissociation of single-stranded DNA-binding proteins (SSBs). Understanding the mechanism may facilitate the development of clinical strategies for cancer therapy, improve the safety of stem cell therapy, and prevent pathological aging.

cell biology↗

bioRxiv2018

The complete plastid genomes of two Fabaceae orphan crops from Africa

Dolichos bean (Lablab purpureus) and Bambara groundnut (Vigna subterranea) are two traditional crops from Africa with important economic values. The study of such neglected or underused crops (orphan crops) should contribute to the resolution of food shortage in Africa. Here we assembled and described the complete plastid genome of the two Fabaceae orphan crop species. The length of the complete plastomes of L. purpureus and V. subterranea are 151,753 bp and 152,015 bp, respectively. Maximum-likelihood (ML) phylogenetic analyses indicated that L. purpureus and Phaseolus vulgaris are closely related, and V. subterranea and other Vigna species are clustered in one clade, which is congruent with former studies.

genomics↗

bioRxiv2018

Unbiased Age-Appropriate Structural Brain Atlases for Chinese Pediatrics

In magnetic resonance imaging (MRI) studies of children brain development, structural brain atlases usually serve as important references of pediatric population in which individual images are spatially normalized into a common or standard stereotactic space. However, the existing popular children brain atlases (e.g., National Institutes of Health pediatric atlases, NIH-PD atlases) are made mostly based on MR images from Western populations, and are thus insufficient to characterize the brains of Chinese children due to the neuroanatomical differences that are relevant to genetic and environmental factors. By collecting high-quality T1- and T2- weighted MR images from 328 typically developing Chinese children aged from 6 to 12 years old, we created a set of age-appropriate Chinese pediatric (CHN-PD) atlases using an unbiased template construction algorithm. The CHN-PD atlases included the head/brain templates, the symmetric brain template, the gender-specific brain templates and the corresponding tissue probability atlases. Moreover, the atlases contained multiple age-specific templates with a one-year interval. A direct comparison of the CHN-PD and the NIH-PD atlases revealed remarkable anatomical differences bilaterally in the lateral frontal and parietal regions and somatosensory cortex. While applying the CHN-PD atlases to two independent Chinese pediatric datasets (N = 114 and N = 71, respectively), machine-learning regression approaches revealed higher prediction accuracy on brain ages than the usage of NIH-PD atlases. These results suggest that the CHN-PD brain atlases are necessary and important for future typical and atypical developmental studies in Chinese pediatric population. Currently, the CHN-PD atlases have been released on the NITRC website (https://www.nitrc.org/projects/chn-pd).

neuroscience↗

bioRxiv2018

WDR45 contributes to neurodegeneration through regulation of ER homeostasis and neuronal death

Mutations in the autophagy gene WDR45 cause {beta}-propeller protein-associated neurodegeneration (BPAN); however the molecular and cellular mechanism of the disease process is largely unknown. Here we generated constitutive Wdr45 knockout (KO) mice that displayed cognitive impairments, abnormal synaptic transmission and lesions in hippocampus and basal ganglia. Immunohistochemistry analysis shows loss of neurons in prefrontal cortex and basal ganglion in aged mice, and increased apoptosis in these regions, recapitulating a hallmark of neurodegeneration. Quantitative proteomic analysis shows accumulation of endoplasmic reticulum (ER) proteins in KO mouse. Furthermore, we show that a defect in autophagy results in impaired ER turnover and ER stress. The unfolded protein response (UPR) is elevated through IRE1 and possibly other kinase signaling pathways, and eventually leads to neuronal apoptosis. Suppression of ER stress, or activation of autophagy through inhibition of mTOR pathway rescues neuronal death. Thus, our study not only provides mechanistic insights for BPAN, but also suggests that a defect in macroautophagy machinery leads to impairment in selective organelle autophagy.

cell biology↗