bioRxiv Science⌕ Search

Biology subjects

Zhuang, Q.

Publications and source records attributed to Zhuang, Q..

13 recordsLinked to original sources

Wheat MYB transcription factor TaMYB83-7B regulates seed dormancy by influencing the balance between abscisic acid and gibberellin

In wheat, weak seed dormancy (SD) is related to an increased tendency for pre-harvest sprouting (PHS), which reduces yield and quality. However, the molecular mechanism underlying SD remains elusive. Here, we identified a wheat R2R3-MYB transcription factor (TaMYB83-7B) related to SD. Expression analysis showed that TaMYB83-7B was highly expressed in wheat seeds, and was more highly expressed in strong-dormancy varieties than in weak-dormancy varieties. Sequence and association analysis indicated that T/C mutations at -907 bp and -1133 bp in the TaMYB83-7B promoter were significantly associated with wheat SD, with C at both sites related to strong dormancy. Dual-luciferase reporter assays demonstrated that the transcriptional activity of the TaMYB83-7B promoter was significantly higher in strong-dormancy varieties than in weak-dormancy varieties. Further analyses indicated that TaMYB83-7B functions as a transcriptional inhibitor. Germination experiments revealed that overexpression of TaMYB83-7B significantly enhanced SD, while its loss-of-function reduced SD. Finally, TaMYB83-7B was found to regulate SD by influencing the balance between abscisic acid (ABA) and gibberellin (GA) in wheat seeds. Overall, the results of this study enhance our understanding of the complex regulatory mechanism underlying SD, and provide gene targets and molecular markers for the genetic improvement of PHS resistance in wheat.

molecular biology↗

A functional anatomical shift from the lateral frontal pole to dorsolateral prefrontal cortex in emotion action control underpins elevated levels of anxiety: partial replication and generalization of Bramson et al., 2023

Flexible control over emotional behavior represents a promising target for novel interventions for mental disorders. Accumulating evidence has indicated a key role of the lateral frontal pole (FPl) and its connections with other cortical and subcortical systems in emotional action regulation. A recent study from Bramson et al., (2023) employed a multi-modal neuroimaging approach to demonstrate a functional-anatomical shift from FPI to dorsolateral prefrontal cortex (DLPFC) in a sample of anxious individuals during emotional action control. While these findings might represent a venue for interventions in anxiety disorders, conventional neuroimaging strategies are often limited with respect to generalizability and reproducibility. Against this background we capitalized previous large-scale fMRI data in n = 250 participants using an affective linguistic Go/NoGo paradigm to examine the robustness of the reported associations with trait social anxiety across samples, cultures and paradigms. Additionally, context-dependent functional connectivity patterns were explored to examine action control in different emotional contexts. In line with previous study, we found no difference between high- and non-anxious group on the behavioral congruency-effect. The neural results showed that non-social anxious group engaged the left FPl while the high-social anxious group specifically recruited the DLPFC, however in the absence of significant between-group differences. Importantly, the level of trait social anxiety was significantly positively related with DLPFC activity and negatively with left FPl activation across groups. Furthermore, context-dependent functional connectivity analyses revealed a negative context-specific neural shift from the sgACC-FPl to sgACC-DLPFC specifically in the high anxiety group. Together, the present study employed a different task paradigm, population and analytic methods, partially replicated the findings described by Bramson et al., (2023) and additionally determined context-specific changes in the communication with the sgACC in high anxiety. The findings provide further evidence for target-based interventions of persistent emotional control deficits in anxiety disorders.

neuroscience↗

Modulating the epigenetic state promotes the reprogramming of transformed cells to pluripotency in a line-specific manner

Somatic cell reprogramming and oncogenic transformation share surprisingly similar features, yet transformed cells are highly resistant to reprogramming. There must be barriers that block transformed cells from reprogramming, but the nature of those barriers is unclear. In this study, we generated a systematic panel of transformed mouse embryonic fibroblasts (MEFs) using a variety of oncogenic transgenes, and discovered transformed cell lines that remain compatible with reprogramming when transfected with Oct4/Sox2/Klf4/Myc. By comparing the reprogramming-capable and incapable transformed lines we identified multiple stages of failure in the reprogramming process. Some transformed lines failed very early, whilst other lines seemed to progress through a normal-looking reprogramming process. Finally, we show that MEK inhibition overcomes one critical reprogramming barrier by indirectly suppressing a hyperactive epigenetic state in some of the transformed cells. This study reveals that the barriers underlying resistance to reprogramming vary between the different transformation methods. Key findingsO_LISomatic cell reprogramming of transformed cells is context-specific C_LIO_LIInhibition of MEK converts some cell lines to reprogramming-capable C_LIO_LITransformed cell lines are characterized by a hyperactive chromatin state C_LIO_LIMEK inhibition indirectly affects chromatin to enable reprogramming C_LI

cell biology↗

The right inferior frontal gyrus as pivotal node and effective regulator of the basal ganglia-thalamocortical response inhibition circuit in humans

The involvement of specific basal ganglia-thalamocortical circuits in response inhibition has been extensively mapped in the last few decades. However, the pivotal brain nodes and directed casual regulation within this inhibitory circuit in humans remains controversial. Here, we capitalize on recent progress in robust and biologically plausible directed causal modelling (DCM-PEB) and a large fMRI response inhibition dataset (n=218) to determine key nodes, their causal regulation and modulation via biological variables (sex) and inhibitory performance in the inhibitory control circuit encompassing the right inferior frontal gyrus (rIFG), caudate nucleus (rCau), globus pallidum (rGP) and thalamus (rThal).The entire neural circuit exhibited high intrinsic connectivity and an increasing rIFG inflow and its causal regulation over the rCau and rThal during response inhibition. In addition, sex and behavioral performance influenced the architecture of the regulatory circuits such that women displayed increased rThal self-inhibition and decreased rThal to GP modulation, while better inhibitory performance was associated with stronger rThal to rIFG communication. Furthermore, control analyses did not reveal a similar key communication in a left lateralized model. Together these findings indicate a pivotal role of the rIFG as input and causal regulator of subcortical response inhibition nodes.

neuroscience↗

Intranasal vasopressin like oxytocin increases social attention by influencing top-down control, but additionally enhances bottom-up control

The respective roles of the neuropeptides arginine vasopressin (AVP) and oxytocin (OXT) in modulating social cognition and for therapeutic intervention in autism spectrum disorder have not been fully established. In particular, while numerous studies have demonstrated effects of oxytocin in promoting social attention the role of AVP has not been examined. The present study employed a randomized, double-blind, placebo (PLC)-controlled between-subject design to explore the social- and emotion-specific effects of AVP on both bottom-up and topdown attention processing with a validated emotional anti-saccade eye-tracking paradigm in 80 male subjects (PLC = 40, AVP = 40). Our findings showed that AVP increased the error rate for social (angry, fearful, happy, neutral and sad faces) but not non-social (oval shapes) stimuli during the anti-saccade condition and reduced error rates in the pro-saccade condition. Comparison of these findings with a previous study (sample size: PLC = 33, OXT = 33) using intranasal oxytocin revealed similar effects of the two peptides on anti-saccade errors but a significantly greater effect of AVP on pro-saccades. Both peptides also produced a post-task anxiolytic effect by reducing state anxiety. Together these findings suggested that both AVP and OXT decrease goal-directed top-down attention control to social salient stimuli but that AVP more potently increased bottom-up social attentional processing.

neuroscience↗

Segregating domain-general from emotional context-specific inhibitory control systems - ventral striatum and orbitofrontal cortex serve as emotion-cognition integration hubs

Inhibitory control hierarchically regulates cognitive and emotional systems in the service of adaptive goal-directed behavior across changing task demands and environments. While previous studies convergently determined the contribution of prefrontal-striatal systems to general inhibitory control, findings on the specific circuits that mediate the context-specific impact of inhibitory control remained inconclusive. Against this background we employed an evaluated emotional Go/No Go task with fMRI in a large cohort of subjects (N = 250) to segregate brain systems and circuits that mediate domain-general from emotion-specific inhibition control. Particularly during a positive emotional context, behavioral results showed a lower accuracy for No Go trials and a faster response time for Go trials. While the dorsal striatum and lateral frontal regions were involved in inhibitory control irrespective of emotional context, activity in the ventral striatum (VS) and medial orbitofrontal cortex (mOFC) varied as a function of emotional context. On the voxel-wise network level, limbic and striatal systems generally exhibited highest changes in global brain connectivity during inhibitory control, while global brain connectivity of the left mOFC was less suppressed during emotional contexts. Functional connectivity analyses moreover revealed that negative coupling between the VS with inferior frontal gyrus (IFG)/insula and mOFC varied as a function of emotional context. Together these findings indicated separable domain general systems as well emotional context-specific inhibitory brain systems which specifically encompass the VS and its connections with frontal regions.

neuroscience↗

Reverse-transcription recombinase-aided amplification assay for H5 subtype avian influenza virus

The H5 subtype Avian Influenza Virus has caused huge economic losses to the poultry industry and is a threat to human health. A rapid and simple test is needed to confirm infection in suspected cases during disease outbreaks. In this study, we developed a reverse-transcription recombinase-aided amplification assay for the detection of H5 subtype avian influenza virus. Assays were performed at a single temperature (39{degrees}C), and the results were obtained within 20 min. The assay showed no cross-detection with Newcastle disease virus or infectious bronchitis virus. The analytical sensitivity was 103 RNA copies per reaction at a 95% confidence interval according to probit regression analysis, with 100% specificity. Compared with published reverse-transcription quantitative real-time polymerase chain reaction assays, the {kappa} value of the reverse transcription recombinase-aided amplification assay in 365 avian clinical samples was 0.970 (p < 0.001). The sensitivity for avian clinical sample detection was 94.44% (95%CI, 70.63% - 99.71%), and the specificity was 100% (95%CI, 98.64% - 100%). These results indicated that our reverse-transcription recombinase-aided amplification assay may be a valuable tool for detecting H5 subtype avian influenza virus.

molecular biology↗

Transposable Element-Gene Splicing Modulates the Transcriptional Landscape of Human Pluripotent Stem Cells

Transposable elements (TEs) occupy nearly 50% of mammalian genomes and are both potential dangers to genome stability and functional genetic elements. TEs can be expressed and exonised as part of a transcript, however, their full contribution to the transcript splicing remains unresolved. Here, guided by long and short read sequencing of RNAs, we show that 26% of coding and 65% of non-coding transcripts of human pluripotent stem cells (hPSCs) contain TEs. Different TE families have unique integration patterns with diverse consequences on RNA expression and function. We identify hPSC-specific splicing of endogenous retroviruses (ERVs) as well as LINE L1 elements into protein coding genes that generate TE-derived peptides. Finally, single cell RNA-seq reveals that proliferating hPSCs are dominated by ERV-containing transcripts, and subpopulations express SINE or LINE-containing transcripts. Overall, we demonstrate that TE splicing modulates the pluripotency transcriptome by enhancing and impairing transcript expression and generating novel transcripts and peptides.

genomics↗

Unveiling transposable element expression heterogeneity in cell fate regulation at the single-cell level

Transposable elements (TEs) make up a majority of a typical eukaryotes genome, and contribute to cell heterogeneity and fate in unclear ways. Single cell-sequencing technologies are powerful tools to explore cells, however analysis is typically gene-centric and TE activity has not been addressed. Here, we developed a single-cell TE processing pipeline, scTE, and report the activity of TEs in single cells in a range of biological contexts. Specific TE types were expressed in subpopulations of embryonic stem cells and were dynamically regulated during pluripotency reprogramming, differentiation, and embryogenesis. Unexpectedly, TEs were expressed in somatic cells, including human disease-specific TEs that are undetectable in bulk analyses. Finally, we applied scTE to single cell ATAC-seq data, and demonstrate that scTE can discriminate cell type using chromatin accessibly of TEs alone. Overall, our results reveal the dynamic patterns of TEs in single cells and their contributions to cell fate and heterogeneity.

bioinformatics↗

Crystal structure of steroid reductase SRD5A reveals conserved steroid reduction mechanism

Steroid hormones are essential in stress response, immune system regulation, and reproduction in mammals. Steroids with 3-oxo-{Delta}4 structure, such as testosterone, androstenedione and progesterone, could be catalyzed by steroid 5-reductases (SRD5As) to generate their corresponding 3-oxo-5 steroids, which are essential for multiple physiological and pathological processes. Abnormal activities of SRD5As will lead to benign prostatic hyperplasia, alopecia, prostatic cancer or infertility due to the poor quality of sperms. However, the detailed reduction mechanisms of SRD5As remain elusive. Here we report the crystal structure of PbSRD5A, which shares 60.6% and 51.5% sequence similarities with human SRD5A1 and -2 respectively, from Proteobacteria bacterium in complex with the cofactor NADPH at 2.0 [A] resolution. PbSRD5A exists as a monomer comprised of seven transmembrane segments (TMs). The TM1-4 enclose a hydrophobic cavity for steroids substrates binding, whereas TM5-7 coordinate with cofactor NADPH through extensive hydrogen bonds network. Homology-based structural models of HsSRD5A1 and -2, together with extensive biochemical characterizations, for the first time unveiled the substrate recognition of SRD5As and provide an important framework for further understanding of the mechanism of NADPH mediated steroids 3-oxo-{Delta}4 reduction. Based on these analyses, the design of therapeutic molecules targeting SRD5As with improved specificity and therapeutic efficacy would be possible. One Sentence SummaryStructural and biochemical characterizations decipher the evolutionarily conserved mechanism in steroid 5-reductases catalyzing NADPH mediated steroids reduction.

biochemistry↗

Comparative performance of four nucleic acid amplification tests for SARS-CoV-2 virus

Coronavirus disease 2019 (COVID-19) can be screened and diagnosed through the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by real-time reverse transcription polymerase chain reaction. SARS-CoV-2 nucleic acid amplification tests (NAATs) have been rapidly developed and quickly applied to clinical testing during the pandemic. However, studies evaluating the performance of these NAAT assays are limited. We evaluated the performance of four NAATs, which were marked by the Conformite Europeenne and widely used in China during the pandemic. Results showed that the analytical sensitivity of the four assays was significantly lower than that claimed by the NAAT manufacturers. The limit of detection (LOD) of Daan, Sansure, and Hybribio NAATs was 3000 copies/mL, whereas the LOD of Bioperfectus NAATs was 4000 copies/mL. The results of the consistency test using 46 samples showed that Daan, Sansure, and Hybribio NAATs could detect the samples with a specificity of 100% (30/30) and a sensitivity of 100% (16 /16), whereas Bioperfectus NAAT detected the samples with a specificity of 100% (30/30) and a sensitivity 81.25% (13/16). The sensitivity of Bioperfectus NAAT was lower than that of the three other NAATs; this finding was consistent with the result that Bioperfectus NAAT had a higher LOD than the three other kinds of NAATs. The four above mentioned reagents presented high specificity; however, for the detection of the samples with low virus concentration, Bioperfectus reagent had the risk of missing detection. Therefore, the LOD should be considered in the selection of SARS-CoV-2 NAATs.

molecular biology↗

Chamaeleo: a robust library for DNA storage coding schemes

Chamaeleo is currently the only collection library that focuses on adapting multiple well-established coding schemes for DNA storage. It provides a tool for researchers to study various coding schemes and apply them in practice. Chamaeleo adheres to the concept of high aggregation and low coupling for software design which will enhance the performance efficiency. Here, we describe the working pipeline of Chamaeleo, and demonstrate its advantages over the implementation of existing single coding schemes. The source code is available at https://github.com/ntpz870817/Chamaeleo, it can be also installed by the command of pip.exe, "pip install chamaeleo". Alternatively, the wheel file can be downloaded at https://pypi.org/project/Chamaeleo/. Detailed documentation is available at https://chamaeleo.readthedocs.io/en/latest/. Author SummaryDNA is now considered to be a promising candidate media for future digital information storage in order to tackle the global issue of data explosion. Transcoding between binary digital data and quanternary DNA information is one of the most important steps in the whole process of DNA digital storage. Although several coding schemes have been reported, researchers are still investigating better strategies. Moreover, the scripts of these coding schemes use different programming languages, software architectures and optimization contents. Therefore, we here introduce Chamaeleo, a library in which several classical coding schemes are collected, to reconstruct and optimize them. One of the key features of this tool is that we modulize the functions and make it feasible for more customized way of usage. Meanwhile, developers can also incorporate their new algorithms according to the framework expediently. Based on the benchmark tests we conducted, Chamaeleo shows better flexibility and expandability compared to original packages and we hope that it will help the further study and applications in DNA digital storage.

bioinformatics↗

Deconvolving multiplexed protease signatures with substrate reduction and activity clustering

Proteases are pleiotropic, promiscuous enzymes that degrade proteins and peptides, which drive important processes in health and disease. The ability to quantify the activity of protease signatures by sampling with Massively Multiplexed Activity (MMA) libraries will provide unparalleled biological information. Under such a framework, a designed library of peptide substrates is exposed to a cocktail of proteases, the cleavage velocity of each substrate is measured, and individual protease activity levels are inferred from the data. Previous studies have developed individual protease sensors, but multiplexed substrate cleavage data becomes difficult to interpret as the number of cross-cutting proteases increases. Computational methods for parsing this data to estimate individual protease activities primarily use an extensive compendium of all possible protease-substrate combinations, which require impractical amounts of training data when scaling up to MMA libraries. Here we provide a computational method for estimating protease activities efficiently by reducing the number of substrates and clustering proteases with similar cleavage activities into families. This method is scalable and will enable the future use of MMA libraries with applications spanning therapeutic and diagnostic biotechnology.

bioengineering↗