Biology subjects

Wang, N.

Publications and source records attributed to Wang, N..

At least 145 records · Page 8Linked to original sources

bioRxiv2024

A detailed analysis of 16S rRNA gene sequencing and conventional PCR-based testing for the diagnosis of bacterial pathogens and discovery of novel bacteria

This study represents the first analysis of the bacterial community in chickens affected by swollen head syndrome, utilizing 16S rRNA gene sequencing. Samples were obtained from clinical laying chickens and were examined for the presence of Avibacterium paragallinarum (APG) and Ornithobacterium rhinotracheale (ORT) using conventional polymerase chain reaction (PCR). From the samples, five APG-positive (APG) and APG-negative (N-APG) samples were chosen, along with five specific pathogen-free chickens, for 16S rRNA gene sequencing. Results showed that APG and ORT were widely detected in the chicken samples with swollen head syndrome (SHS, 9/10), while APG was detected in all five specific pathogen-free (SPF) samples. In contrast, conventional PCR sensitivity was found to be inadequate for diagnosis, with only 35.7% (5/14) and 11.1% (1/9) sensitivity for APG and ORT, respectively, based on 16S rRNA gene sequencing data. Furthermore, 16S rRNA gene sequencing was able to quantify the bacteria in the samples, revealing that the relative abundance of APG in the APG group ranged from 2.7% to 81.3%, while the relative abundance of APG in the N-APG group ranged from 0.1% to 21.0%. Notably, a low level of APG was also detected in all 5 SPF samples. The study also identified a significant number of animal and human common bacterial pathogens, including but not limited to Gallibacterium anatis, Riemerella columbina, Enterococcus cecorum, Mycoplasma synoviae, Helicobacter hepaticus, and Staphylococcus lentus. In conclusion, 16S rRNA gene sequencing is a valuable tool for bacterial pathogen diagnosis and the discovery of novel bacterial pathogens, while conventional PCR is not reliable for diagnosis.

microbiology↗

bioRxiv2024

A transcription factor quartet orchestrating bundle sheath expression in rice

C4 photosynthesis has evolved in over sixty plant lineages and improves photosynthetic efficiency by [~]50%. One unifying character of C4 plants is photosynthetic activation of a compartment such as the bundle sheath, but gene regulatory networks controlling this cell type are poorly understood. In Arabidopsis a bipartite MYC-MYB transcription factor module restricts gene expression to these cells but in grasses the regulatory logic allowing bundle sheath gene expression has not been defined. Using the global staple and C3 crop rice we identified the SULFITE REDUCTASE promoter as sufficient for strong bundle sheath expression. This promoter encodes an intricate cis-regulatory logic with multiple activators and repressors acting combinatorially. Within this landscape we identified a distal enhancer activated by a quintet of transcription factors from the WRKY, G2-like, MYB-related, IDD and bZIP families. This module is necessary and sufficient to pattern gene expression to the rice bundle sheath. Oligomerisation of the enhancer and fusion to core promoters containing Y-patches allowed activity to be increased 220-fold. This enhancer generates bundle sheath-specific expression in Arabidopsis indicating deep conservation in function between monocotyledons and dicotyledons. In summary, we identify an ancient, short, and tuneable enhancer patterning expression to the bundle sheath that we anticipate will be useful for engineering this cell type in various crop species.

plant biology↗

bioRxiv2024

Cas12a/3 crRNAs RNP transformation enables transgene-free multiplex genome editing, long deletions, and inversions in citrus chromosome in the T0 generation

Citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), is a devastating disease worldwide. Previously, we successfully generated canker-resistant Citrus sinensis cv. Hamlin lines in the T0 generation, achieving a mutation efficiency of 97.4%. This was achieved through the transformation of embryogenic protoplasts using the Cas12a/1 crRNA ribonucleoprotein (RNP) system to edit the canker susceptibility gene, CsLOB1, which led to small indels. Here, we transformed embryogenic protoplasts of Hamlin with Cas12a/3 crRNAs RNP, resulting in 100% efficiency in editing the CsLOB1 gene in the T0 generation. Among the 10 transgene-free genome-edited lines, long deletions were obtained in five lines. Additionally, inversions were observed in three of the five edited lines with long deletions, but not in any edited lines with short indel mutations, suggesting long deletions are required for inversions. Biallelic mutations were observed for each of the three target sites in 4 of the 10 edited lines when 3 crRNAs were used, demonstrating that transformation of embryogenic citrus protoplasts with Cas12a/3 crRNAs RNP can be very efficient for multiplex editing. Our analysis revealed the absence of off-target mutations in the edited lines. These cslob1 mutant lines were canker-resistant and no canker symptoms were observed after inoculation with Xcc and Xcc growth was significantly reduced in the cslob1 mutant lines compared to the wild type plants. Taken together, Cas12a/3 crRNAs RNP transformation of embryogenic protoplasts of citrus provides a promising solution for transgene-free multiplex genome editing with high efficiency and for deletion of long fragments.

plant biology↗

bioRxiv2024

Liver-like glycogen metabolism supports glycolysis in naked mole-rat heart during ischaemia

As a subterranean eusocial mammal, the naked mole-rat faces a particularly challenging environment characterised by patchily available food, low O2 and high CO2 levels. In response, naked mole-rats have evolved a suite of molecular and physiological adaptations to survive extreme hypoxia. Yet, how naked mole-rats rewire their metabolism to protect the heart has not been comprehensively addressed. Here, we performed comparative analyses of naked mole-rat and mouse organs exposed to ischaemic conditions. We show that naked mole-rats have retained features of foetal cardiac metabolism replacing fatty acid utilisation for a unique type of carbohydrate metabolism largely dependent on glycogen. We found that naked mole-rats have co-opted specialised liver-like glycogen handling mechanisms in the heart. Amongst these is the expression of liver-specific enzyme isoforms and amylase, a digestive enzyme known for starch breakdown in saliva and intestine but whose biological role in glycogen processing has not been fully recognised. We show that amylase is rapidly activated in ischaemia and hydrolyses internal glycosidic bonds for more efficient downstream processing. This biochemical adaptation occurred in both mouse and naked mole-rat livers but exclusively in the naked mole-rat heart, which retained higher ATP levels by maintaining an increased glycolytic flux in an amylase-dependent mechanism. Overall, we discovered a previously unknown type of glycogen metabolism in the naked mole-rat that holds relevance to pathologies where glycogen plays a role. Furthermore, we describe a novel type of metabolic plasticity in the heart which may be harnessed for cardiac disease.

molecular biology↗

bioRxiv2024

ALBA proteins facilitate cytoplasmic YTHDF-mediated reading of m6A in plants

N6-methyladenosine (m6A) exerts many of its regulatory effects on eukaryotic mRNAs by recruiting cytoplasmic YT521-B homology domain family (YTHDF) proteins. Here, we show that in Arabidopsis, the interaction between m6A and the major YTHDF protein ECT2 also involves the mRNA-binding ALBA protein family. ALBA and YTHDF proteins physically associate via a deeply conserved short linear motif in the intrinsically disordered region of YTHDF proteins, their mRNA target sets overlap, and ALBA4 binding sites are juxtaposed to m6A sites. These binding sites correspond to pyrimidine-rich elements previously found to be important for m6A binding of ECT2. Accordingly, both biological functions of ECT2 and its binding to m6A targets in vivo require ALBA association. Our results introduce the YTHDF-ALBA complex as the functional cytoplasmic m6A-reader in plants and define a molecular foundation for the concept of facilitated m6A reading that increases the potential for combinatorial control of biological m6A effects.

molecular 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

The genomic and epigenomic dynamics of hemizygous genes across crops with contrasting mating systems

Hemizygous genes, which present on only one of the two homologous chromosomes of diploid organisms, have been mainly studied in the context of sex chromosomes and sex-linked genes. However, structural variants (SVs), such as a deletion/insertion of one allele, can lead to hemizygous genes, a phenomenon largely unexplored in plants. Here, we investigated the genomic and epigenomic landscapes of hemizygous genes across 22 genomes with varying propagation histories: eleven clonal lineages, seven outcrossed samples and four inbred and putatively homozygous genomes. We identified SVs leading to genic hemizygosity. As expected, very few genes (0.01%-1.2%) were hemizygous in the homozygous genomes, representing negative controls. Hemizygosity was appreciable among outcrossed lineages, averaging 8.7% of genes, but consistently elevated for the clonal samples at 13.8% genes, likely reflecting heterozygous SVs accumulation during clonal propagation. Compared to diploid genes, hemizygous genes were more often situated in centromeric than telomeric regions and underlying weaker purifying selection. They also had reduced levels of expression, averaging [~]20% of the expression levels of diploid genes, violating the evolutionary model of dosage compensation. We also detected higher DNA methylation levels, in hemizygous genes and transposable elements, which may contribute to the reduced expression of hemizygous genes. Finally, expression profiles showed that hemizygous genes were more specifically expressed in contexts related to fruit development, organ differentiation and stress responses. Overall, hemizygous genes accumulate in clonally propagated lineages and display distinct genetic, and epigenetic features compared to diploid genes, shedding new insights on genetic studies and breeding programs of clonal crops.

plant biology↗

bioRxiv2024

Functional Activity, Functional Connectivity and Complex Network Biomarkers of Progressive Hyposmia Parkinson's Disease with No Cognitive Impairment: Evidences from Resting-state fMRI Study

BackgroundOlfactory dysfunction stands as one of the most prevalent non-motor symptoms in the initial stage of Parkinsons disease (PD). Nevertheless, the intricate mechanisms underlying olfactory deficits in Parkinsons disease still remain elusive. MethodsThis study collected rs-fMRI data from 30 PD patients (15 with severe hyposmia (PD-SH) and 15 with no/mild hyposmia (PD-N/MH)) and 15 healthy controls (HC). To investigate functional segregation, the amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) were utilized. Functional connectivity (FC) analysis was performed to explore the functional integration across diverse brain regions. Additionally, the graph theory-based network analysis was employed to assess functional networks in PD patients. Furthermore, Pearson correlation analysis was conducted to delve deeper into the relationship between the severity of olfactory dysfunction and various functional metrics. ResultsFirstly, PD patients showed significantly higher ALFF values in the superior temporal gyrus compared to HC, especially in the PD-SH group versus PD-N/MH. Meanwhile, ALFF values in this region negatively correlated with olfactory testing scores. Secondly, PD patients had higher ReHo in middle temporal gyrus and superior frontal gyrus than HC, especially PD-SH. Meanwhile, olfactory scores negatively correlated with these ReHo values. Thirdly, we observed a negative correlation between superior cerebellar-insula connectivity and olfactory scores, suggesting a neural circuit link to olfactory dysfunction. Lastly, the PD patients brain networks consistently showed small-world attributes, with the PD-N/MH group having significantly higher nodal betweenness in the superior cerebellum than the PD-SH group. Theres also a positive link between superior cerebellums betweenness and olfactory scores. Additionally, there is a notable difference in the node degree of the superior temporal gyrus when comparing the PD-SH group to the PD-N/MH group. ConclusionUsing fMRI, our study analyzed brain function in PD-SH, PD-N/MH, and HC groups, revealing impaired segregation and integration in PD-SH and PD-N/MH. We hypothesize that changes in temporal, frontal, occipital, and cerebellar activities, along with aberrant cerebellum-insula connectivity and node degree and betweenness disparities, may be linked to olfactory dysfunction in PD patients.

neuroscience↗

bioRxiv2024

Asymmetric binding of coactivator SRC1 to FXR-RXR and allosteric communication within the complex

Farnesoid X receptor (FXR) is a promising target for treatment of metabolic associated fatty liver disease (MAFLD). In this study, we employed an integrative approach to investigate the interaction between FXR-RXR-hSHP-1 complex and the entire coactivator SRC1-NRID (nuclear receptor interaction domain). We constructed a multi-domain model of FXR120-RXR98-hSHP-1, highlighting the interface between FXR-DBD and LBD. Using HDX-MS, XL-MS, and biochemical assays, we revealed the allosteric communications in FXR-RXR-hSHP-1 upon agonist and DNA binding. We then demonstrated that SRC1 binds only to the coactivator binding surface of FXR within the FXR-RXR heterodimer, with the NR-box2 and NR-box3 of SRC1 as the key binding motifs. Our findings, which provide the first model of SRC1-NRID in complex with FXR-RXR-hSHP-1, shed light on the molecular mechanism through which the coactivator asymmetrically interacts with nuclear receptors and provide structural basis for further understanding the function of FXR and its implications in diseases.

biophysics↗

bioRxiv2024

Insulin evokes release of endozepines from astrocytes of the NTS to modulate glucose metabolism

The central nervous system (CNS) plays a key role in regulating metabolic functions, but conditions like obesity and diabetes can disrupt this balance. Within the CNS, the nucleus of the solitary tract (NTS) in the dorsal vagal complex (DVC) controls glucose metabolism and feeding behaviour. In rodents, the NTS senses insulin and communicates with the liver to regulate glucose production. Even short-term exposure to a high-fat diet (HFD) can lead to insulin resistance and impair NTS function. However, we still know little about which cells in the NTS are sensitive to insulin. Our study aimed to identify these insulin-sensitive cells and understand how they affect glucose metabolism. We found that insulin receptors in astrocytes are crucial for the NTSs ability to regulate glucose production in the liver. Insulin evokes the release of endozepines from astrocytes, and injecting endozepines into the NTS reduces glucose production. The effect of endozepines within the NTS is mimicked by GABAA antagonists and prevented by an agonist, suggesting that insulin prompts astrocytes to release endozepines, which then attenuate GABAA receptor activity, ultimately reducing glucose production in the liver. Our study is the first to show that insulin-dependent release of endozepines from NTS- astrocytes is fundamental to control blood glucose levels, providing valuable insights into the mechanisms underlying insulin function within this specific region of the CNS.

neuroscience↗

bioRxiv2024

Maternal obesity may disrupt offspring metabolism by inducing oocyte genome hyper-methylation via increased DNMTs

Maternal obesity has deleterious effects on the process of establishing oocyte DNA methylation; yet the underlying mechanisms remain unclear. In the present study, we found that maternal obesity induced by high-fat diet (HFD) disrupted the genomic methylation of oocytes, and that at least a part of the altered DNA methylation was transmitted to the F2 oocytes and the livers via females. We further examined the metabolome of serum and found that the altered metabolites such as melatonin may play a key role in the disrupted genomic methylation in the oocytes of obese mice. We further found that exogenous melatonin treatment significantly reduced the hyper-methylation of HFD oocytes, and the increased expression of DNMT3a and DNMT1 in HFD oocytes was also decreased. To address how melatonin regulates the expression of DNMTs, the function of melatonin was inhibited or activated upon oocytes. Results revealed that melatonin may regulate the expression of DNMTs via the cAMP/PKA/CREB pathway. These results suggest that maternal obesity induces genomic methylation alterations in oocytes, which can be partly transmitted to F2 in females, and that melatonin is involved in regulating the hyper-methylation of HFD oocytes by increasing the expression of DNMTs via the cAMP/PKA/CREB pathway.

developmental biology↗

bioRxiv2024

SHP-1 interacts with NFκB1 to inhibit its phosphorylation and nuclear translocation to suppress excessive bacterial inflammation

The protein tyrosine phosphatase SHP-1 is a key negative regulator in cancer by dephosphorylating multiple target molecules. Specially in the NF{kappa}B signaling, where NF{kappa}B1/Rela dimer translocate to the nucleus and activate target gene transcription, SHP-1 inhibits the phosphorylation of Rela, while its regulation on NF{kappa}B1 has been unknown, especially in pathogen-induced inflammation. Chinese tongue sole, a representative flatfish, has been widely used as a genomics and disease model. Using the teleost and cellular model, we revealed for the first time that SHP-1 inhibits NF{kappa}B1 phosphorylation and nuclear translocation by interacting with NF{kappa}B1, thereby suppressing NF{kappa}B signaling to inhibit bacterial inflammation. In addition, we showed that SHP-1 decreased mortality and alleviated histopathological deterioration, manifested in the inhibition of immune-related pathways and secretion of pro- inflammatory cytokines. Using cellular model, SHP-1 overexpression reduced macrophages M1 polarization, phagocytosis, and oxidative stress, while silencing SHP- 1 exhibited opposite effects. Our findings systematically dissect the functions of SHP- 1 and provide mechanistic insights into the control of inflammation-related diseases. TeaserSHP-1 help maintain the cellular and individual homeostasis by inhibiting the excessive inflammation and immunity via regulating the NF{kappa}B signaling.

immunology↗

bioRxiv2024

Extracellular vesicles-based point-of-care testing for the diagnosis and monitoring of Alzheimer's disease

Alzheimers disease (AD) is a debilitating condition that affects millions of people worldwide. One promising strategy for detecting and monitoring AD early on is using extracellular vesicles (EVs)-based point-of-care testing; however, diagnosing AD using EVs poses a challenge due to the low abundance of EV-biomarkers. Here, we present a fully integrated organic electrochemical transistor (OECT) that enables high accuracy, speed, and convenience in the detection of EVs from AD patients. We incorporated self-aligned acoustoelectric enhancement of EVs on a chip that rapidly propels, enriches, and specifically binds EVs to the OECT detection area. With our enhancement of pre-concentration, we increased the sensitivity to a limit of detection of 500 EV particles/L and reduced the required detection time to just two minutes. We also tested the sensor on an AD mouse model to monitor AD progression, examined mouse A{beta} EVs at different time courses, and compared them with intraneuronal A{beta} cumulation using MRI. This innovative technology has the potential to diagnose Alzheimers and other neurodegenerative diseases accurately and quickly, enabling monitoring of disease progression and treatment response.

bioengineering↗

bioRxiv2024

Dynamic Gamma Modulation of Hippocampal Place Cells Predominates Development of Theta Sequences

The experience-dependent spatial cognitive process requires sequential organization of hippocampal neural activities by theta rhythm, which develops to represent highly compressed information for rapid learning. However, how the theta sequences were developed in a finer time scale within theta cycles remains unclear. In this study, we found that sweep-ahead structure of theta sequences developing with exploration was predominantly dependent on a relatively large proportion of FG-cells, i.e. a subset of place cells dominantly phase-locked to fast gamma rhythms. These ensembles integrated compressed spatial information by cells consistently firing at precessing slow gamma phases within the theta cycle. Accordingly, the sweep-ahead structure of FG-cell sequences was positively correlated with the intensity of slow gamma phase precession, in particular during early development of theta sequences. These findings highlight the dynamic network-modulation by fast and slow gamma in the development of theta sequences which may further facilitate memory encoding and retrieval.

neuroscience↗

bioRxiv2024

Cluster-free annotation of single cells using Earth mover's distance-based classification

Grouping individual cells in clusters and annotating these based on feature expression is a common procedure in single-cell analysis pipelines. Multiple methods have been reported for single-cell mRNA sequencing and cytometry datasets where the vast majority rely on sequential 2-step procedures involving I) cell clustering based on notions of similarity and II) cluster annotation via manual or semi-automated methods. However, as arbitrary borders are drawn between more or less similar groups of cells, one cannot guarantee that all cells within a cluster are of the same type. Further, dimensionality reduction has been shown to cause considerable distortion in high-dimensional datasets and is prone to variable annotations of the same cell when relative changes occur in data composition. Another limitation of existing methods is that simultaneous analyses of large sets of cells are computationally expensive and difficult to scale for growing datasets or metanalyses across multiple datasets. Here we present an alternative method based on calculation of Earth Movers Distance and a Bayesian classifier coupled to Random Forest, which annotates one cell at a time removing the need for prior clustering and resulting in improved accuracy, better scaling with increasing cell numbers and less computational resources needed.

bioinformatics↗

bioRxiv2024

MetaWorm: A Complete Model Bridging Brain, Body and Environment of C. elegans

The behavior of an organism is profoundly influenced by the complex interplay between its brain, body, and environment. Existing data-driven models focusing on either the brain or the body-environment separately. A model that integrates these two components is yet to be developed. Here, we present MetaWorm, an integrative data-driven model of a widely studied organism, C. elegans. This model consists of two sub-models: the brain model and the body & environment model. The brain model was built by multi-compartment models with realistic morphology, connectome, and neural population dynamics based on experimental data. Simultaneously, the body & environment model employed a lifelike body and a 3D physical environment, facilitating easy behavior quantification. Through the closed-loop interaction between two sub-models, MetaWorm faithfully reproduced the realistic zigzag movement towards attractors observed in C. elegans. Notably, MetaWorm is the first model to achieve seamless integration of detailed brain, body, and environment simulations, enabling unprecedented insights into the intricate relationships between neural structures, neural activities, and behaviors. Leveraging this model, we investigated the impact of neural system structure on both neural activities and behaviors. Consequently, MetaWorm can enhance our understanding of how the brain controls the body to interact with its surrounding environment.

neuroscience↗

bioRxiv2024

Spherical Echo-Planar Time-resolved Imaging (sEPTI) for rapid 3D quantitative T2* and Susceptibility imaging

PurposeTo develop a 3D spherical EPTI (sEPTI) acquisition and a comprehensive reconstruction pipeline for rapid high-quality whole-brain submillimeter T2* and QSM quantification. MethodsFor the sEPTI acquisition, spherical k-space coverage is utilized with variable echo-spacing and maximum kx ramp-sampling to improve efficiency and incoherency when compared to existing EPTI approaches. For reconstruction, an iterative rank-shrinking B0 estimation and odd-even high-order phase correction algorithms were incorporated into the reconstruction to better mitigate artifacts from field imperfections. A physics-informed unrolled network was utilized to boost the SNR, where 1-mm and 0.75-mm isotropic whole-brain imaging were performed in 45 and 90 seconds, respectively. These protocols were validated through simulations, phantom, and in vivo experiments. Ten healthy subjects were recruited to provide sufficient data for the unrolled network. The entire pipeline was validated on additional 5 healthy subjects where different EPTI sampling approaches were compared. Two additional pediatric patients with epilepsy were recruited to demonstrate the generalizability of the unrolled reconstruction. ResultssEPTI achieved 1.4 x faster imaging with improved image quality and quantitative map precision compared to existing EPTI approaches. The B0 update and the phase correction provide improved reconstruction performance with lower artifacts. The unrolled network boosted the SNR, achieving high-quality T2* and QSM quantification with single average data. High-quality reconstruction was also obtained in the pediatric patient using this network. ConclusionsEPTI achieved whole-brain distortion-free multi-echo imaging and T2* and QSM quantification at 0.75 mm in 90 seconds which has the potential to be useful for wide clinical applications.

bioengineering↗

bioRxiv2024

Retrotransposon-mediated variation of a chitin synthase gene confers insect resistance to Bacillus thuringiensis Vip3Aa toxin

Bacillus thuringiensis (Bt) crops expressing Vip3Aa are highly efficacious in controlling major lepidopteran pests and delaying evolution of pest resistance. Although practical resistance to Vip3Aa in the field has not been reported, to proactively manage the pest resistance, there is an urgent need to better understand the genetic basis of resistance to Vip3Aa. This is particularly important for the fall armyworm (Spodoptera frugiperda), one of the most destructive pests around the world, which has evolved practical resistance to Bt crystal (Cry) toxins. Here, a highly Vip3Aa-resistant (resistance ratio: 5,562-fold) strain of S. frugiperda was selected in the laboratory. Results from bulked segregant analysis, fine-scale mapping, and genetic linkage analysis indicate that a mutation in the midgut-specific chitin synthase gene, SfCHS2, is strongly associated with high-level resistance to Vip3Aa. The resistance is ascribed to the transcriptional variation caused by retrotransposon insertion. The same variation of SfCHS2 was also detected in a field population. Importantly, knockout of SfCHS2 via CRISPR/Cas9 in susceptible S. frugiperda confers its complete resistance (>10,000-fold) to Vip3Aa. Also, we demonstrate that knockout of CHS2 can result in complete resistance to Vip3Aa in additional lepidopteran species, suggesting a general role of this gene in Vip3Aa resistance among lepidopteran pests. These results reported here would contribute to monitor and management of pest resistance to Vip3Aa.

genetics↗