Biology subjects

Lei, G.

Publications and source records attributed to Lei, G..

7 recordsLinked to original sources

bioRxiv2026

Adaptive evolution to thermal stress underpins climate resilience in a cosmopolitan arthropod

Adaptive evolution enables species to survive and thrive under changing environmental conditions. In the face of accelerating global climate change, thermal stress represents a major challenge to the persistence of terrestrial arthropods. Understanding the genetic mechanisms underlying thermal adaptation is therefore critical for predicting species evolutionary potential and future success. Here, we combine experimental evolution, phenotypic assays, and multi-omics analyses to investigate the adaptive responses of the diamondback moth (Plutella xylostella), a globally destructive pest of cruciferous crops, to contrasting thermal environments. Populations evolved under hot (32{degrees}C/27{degrees}C) and cold (15{degrees}C/10{degrees}C) regimes exhibited distinct life history and fitness traits relative to those maintained under favorable conditions (26{degrees}C). The hot strain showed accelerated development, higher fecundity, and increased survival under extreme heat, while the cold strain exhibited lower supercooling and freezing points, indicating enhanced cold hardiness. Integrated transcriptomic and metabolomic analyses revealed extensive transcriptional reprogramming and convergent metabolic adjustments, notably a reduction in lipid metabolism to conserve energy under thermal stress. Crucially, non-synonymous mutations in PxSODC enhance superoxide scavenging efficiency, enabling effective oxidative stress management at lower gene expression levels. Furthermore, we identified epigenetic regulation via DNA methylation as a key mediator of this thermal tolerance. Together, these coordinated mutational, epigenetic, and metabolic insights highlight this arthropods capacity for global dispersal and likely persistence under climate change, establishing a framework for understanding equivalent effects in other species.

evolutionary biology↗

bioRxiv2023

Viruses that 'infect' viruses: Cas12f1 and Cas9 gene drive in HSV1

Synthetic CRISPR-Cas9 gene drive has been developed as a potential tool to control harmful species. However, Cas9 gene drive faces high resistance rate and mitigation strategies developed so far are difficult to implement. Furthermore, studying the resistance to gene drive is time consuming and challenging in higher organisms. We here tackled these two challenges simultaneously by generating Cas9 and Un1Cas12f1 gene drive in a fast-replicating DNA virus, HSV1. We assessed the transmission dynamics and resistance formation through phenotypical staining and next-generation sequencing, and demonstrated that HSV1 supported fast and effective transmission of gene drives, and the Un1Cas12f1 gene drives yielded greater conversion and lower resistance than did the Cas9 gene drives. This positions the Un1Cas12f1 gene drive as a promising alternative, and HSV1 emerges as a dependable and swift platform for gene drive assessment. The gene drive viruses function like pathogens that specifically infect viruses, offering potential applications in attenuating viral infections.

microbiology↗

bioRxiv2023

An efficient peptide ligase engineered from a bamboo asparaginyl endopeptidase

In recent years, a few asparaginyl endopeptidases (AEPs) from certain higher plants have been identified as efficient peptide ligases with wide applications in protein labeling and cyclic peptide synthesis. Recently, we developed a NanoLuc Binary Technology (NanoBiT)-based peptide ligase activity assay to identify more AEP-type peptide ligases. Herein, we screened 61 bamboo species from 16 genera using this assay and detected AEP-type peptide ligase activity in the crude extract of all tested bamboo leaves. From a popular bamboo species, Bambusa multiplex, we identified a full-length AEP-type peptide ligase candidate (BmAEP1) via transcriptomic sequencing. After its zymogen was overexpressed in Escherichia coli and self-activated in vitro, BmAEP1 displayed high peptide ligase activity, but with considerable hydrolysis activity. After site-directed mutagenesis of its ligase activity determinants, the mutant zymogen of [G238V]BmAEP1 was normally overexpressed in E. coli, but failed to activate itself. To solve this problem, we developed a novel protease-assisted activation approach in which trypsin was used to cleave the mutant zymogen and was then conveniently removed via an ion-exchange chromatography. After the non-covalently bound cap domain was dissociated from the catalytic core domain under acidic conditions, the recombinant [G238V]BmAEP1 displayed high peptide ligase activity with much lower hydrolysis activity, and could efficiently catalyze inter-molecular protein ligation and intra-molecular peptide cyclization. Thus, the engineered bamboo-derived peptide ligase represents a novel tool for protein labeling and cyclic peptide synthesis.

biochemistry↗

bioRxiv2023

Actomyosin-II Proactively Shields Axons of the Central Nervous System from Mild Mechanical Stress

SummaryPan et al found that actomyosin-II-driven radial contractility underpins the resilience of central axons to mild mechanical stress by suppressing the propagation and firing of injurious Ca2+ waves. Boosting actomyosin-II activity alleviates axon degeneration in mice with traumatic brain injury. Traumatic brain injury (TBI) remains a significant and unmet health challenge. However, our understanding of how neurons, particularly their fragile axons, withstand the abrupt mechanical impacts within the central nervous system remains largely unknown. Using a microfluidic device applying discrete levels of transverse forces to axons, we identified the stress levels that most axons could resist and explored their instant responses at nanoscale resolution. Mild stress induces rapid and reversible axon beading, driven by actomyosin-II-dependent radial contraction, which restricts the spreading and bursting of stress-induced Ca2+ waves. More severe stress causes irreversible focal swelling and Ca2+ overload, ultimately leading to focal axonal swelling and degeneration. Up-regulating actomyosin-II activity prevented the progression of initial injury in vivo, protecting commissural axons from degeneration in a mice TBI model. Our study established a scalable axon injury model and uncovered the critical roles of actomyosin-II in shielding neurons against detrimental mechanical stress.

neuroscience↗

bioRxiv2023

Migratory herbivorous waterfowl couple the seed wave and the green wave during spring migration

East Asian herbivorous waterfowl intensively use farmland in spring, next to their natural habitat. Accordingly, they might have expanded their migration strategy from merely tracking the green wave of newly emerging vegetation to also incorporating the availability of post-harvest agricultural seeds (here dubbed the seed wave). However, if and how waterfowl use multiple food resources to time their seasonal migration is still unknown. We test this migration strategy using 167 spring migration tracks of five East Asian herbivorous waterfowl species and mixed-effect resource selection function models. We find all study species arrive at their core stopover sites in the Northeast China Plain after agricultural seeds become available, extend their stay after spring vegetation emerges, and arrive at breeding sites around the emergence of vegetation. Moreover, the cue used in exploiting the availability of both food resources varies in different regions and among species. At the core stopover sites, larger-bodied species use the seed wave and smaller-bodied ones adopt the green wave. At the breeding sites, the former follow the green wave, and the latter track the snow-free time. Our findings suggest that waterfowl track multiple resource waves to finetune their migration, highlighting new opportunities for conservation.

ecology↗

bioRxiv2020

Complement C3-dependent glutamatergic synapse elimination in the developing hippocampus is region- and synapse-specific

Withdrawal statementThe authors have withdrawn their manuscript owing to the results of this pre-print being based on experiments performed prior to COVID-19 shutdowns, which required a near complete culling of the mouse colony. Upon re-initiating the colony, the phenotype outlined in the pre-print could no longer be observed and as such we have decided to withdraw the pre-print. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

neuroscience↗

bioRxiv2020

Mechanistic insights into ventricular arrhythmogenesis of hydroxychloroquine and azithromycin for the treatment of COVID-19

Background: Recent reports on the use of hydroxychloroquine (HCQ) alone, or combined with azithromycin (AZM) in the management of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have raised cardiac safety concerns. Currently, there is limited mechanistic data evaluating cardiac safety with HCQ and AZM therapy. Methods: Using comprehensive In Vitro ProArrhythmia Assay (CiPA) Schema IC50 paradigms, we examined the cardiac electrophysiological effects of HCQ and HCQ/AZM. Molecular modelling explored HCQ and AZM binding properties to hERG. Langendorff-perfused guinea-pig hearts were electrically and optically mapped by multi-electrode array and voltage (RH237) and Ca2+ (Rhod-2 AM) dyes. Human action potential and ion current reconstructions were performed in silico. Results: HCQ blocked IKr and IK1 with IC50 concentrations (10+-0.6 and 34+-5.0 microM) within the therapeutic range observed clinically. HCQ also blocked INa and ICaL but at higher IC50, whilst Ito and IKs were unaffected. Contrastingly, AZM produced minor inhibition of INa, ICaL, IKs, and IKr,, with no effect on IK1 and Ito. HCQ + AZM combined inhibited IKr and IK1 with IC50s of 7.7 +- 0.8 microM and 30.4 +- 3.0 microM, but spared INa, ICaL and Ito,. Molecular modelling confirmed potential HCQ binding to hERG. Cardiac mapping and ECG studies in isolated hearts demonstrated that HCQ slowed heart rate and ventricular conduction with associated prolongation of PR, QRS and QT intervals. Optical mapping demonstrated, and prolonged, more heterogeneous, action potential durations and intracellular Ca2+ transients. These effects were accentuated with combined HCQ+AZM treatment, which elicited electrical alternans, re-entrant circuits and wave breaks. Reconstruction in a human in-silico model demonstrated that this is attributable to the integrated action of HCQ and AZM reducing IKr, IKs and IK1. Conclusions: These data provide an electrophysiological basis for recent FDA guidelines cautioning against combined HCQ/AZM administration for the treatment of Covid-19 on the grounds of potential cardiac safety. We would strongly recommend monitoring of electrocardiographic QT interval with the use of this combination of medications.Competing Interest StatementThe authors have declared no competing interest.

pharmacology and toxicology↗