Site Mutation Research Articles

MyD88 protein destabilization mitigates NF-κB-dependent protection against macrophage apoptosis.

Various signaling pathways are essential for both the innate immune response and the maintenance of cell homeostasis, requiring coordinated interactions among them. In this study, a mutation in the caspase-1 recognition site within MyD88 abolished inflammasome-dependent negative regulation, causing phenotypic changes in mice with some similarities to human NEMO-deficiencies. The MyD88D162E mutation reduced MyD88 protein levels and colon inflammation in DSS-induced colitis mice but did not affect cytokine expression in bone marrow-derived macrophages (BMDMs). However, compared to MyD88wt counterparts, MyD88D162E BMDMs had increased oxidative stress and dysfunctional mitochondria, along with reduced prosurvival Bcl-xL and BTK expression, rendering cells more prone to apoptosis, exacerbated by ibrutinib treatment. NF-κB activation by lipopolysaccharide mitigated this sensitive phenotype. These findings underscore the importance of MyD88wt signaling for NF-κB activation, protecting against macrophage premature apoptosis at resting state. Targeting MyD88 quantity rather than just its signaling could be a promising strategy for MyD88-driven lymphoma treatment.

Changes in the prognosis of CADASIL over time: a 23-year study in 555 individuals

BackgroundCerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic form of stroke and is associated with early-onset stroke and dementia. Whether its clinical phenotype...

Helicobacter pylori Efflux Pumps: A Double-Edged Sword in Antibiotic Resistance and Biofilm Formation

Helicobacter pylori is a major pathogen associated with various gastric diseases. Despite decades of research, the treatment of H. pylori remains challenging. One of the primary mechanisms contributing to failures of therapies targeting this bacterium is genetic mutations in drug target sites, although the growing body of scientific data highlights that efflux pumps may also take part in this process. Efflux pumps are proteinaceous transporters actively expelling antimicrobial agents from the interior of the targeted cells and reducing the intracellular concentration of these compounds. Considering that efflux pumps contribute to both antimicrobial resistance and biofilm formation, an in-depth understanding of their properties may constitute a cornerstone in the development of novel therapeutics against H. pylori. In line with this, the aim of the current review is to describe the multitude of efflux pumps produced by H. pylori and present the data describing the involvement of these proteins in tolerance and/or resistance to various classes of antimicrobial substances.

Evolution Enhances Kemp Eliminase Activity by Optimizing Oxyanion Stabilization and Conformational Flexibility.

The base-promoted Kemp elimination reaction has been used as a model system for enzyme design. Among the multiple computationally designed and evolved Kemp eliminases generated along the years, the HG3-to-HG3.17 evolutionary trajectory is particularly interesting due to the high catalytic efficiency of HG3.17 and the debated role of glutamine 50 (Gln50) as potential oxyanion stabilizer. This study aims to elucidate the structural and dynamic changes along the evolutionary pathway from HG3 to HG3.17 that contribute to improved catalytic efficiency. In particular, we evaluate key variants along the HG3 evolutionary trajectory via molecular dynamics simulations coupled to non-covalent interactions and water analysis. Our computational study indicates that HG3.17 can adopt a catalytically competent conformation promoted by a water-mediated network of non-covalent interactions, in which aspartate 124 is properly positioned for proton abstraction and both glutamine 50 and mutation cysteine 84 contribute to oxyanion stabilization. We find that HG3.17 exhibits a rather high flexibility of Gln50, which is regulated by the conformation adopted by the active site residue Trp44. This interplay between Gln50 and Trp44 positioning induced by distal active site mutations affects the water-mediated network of non-covalent interactions, Gln50 preorganization, and water content of the active site pocket.

Investigation of resistance mechanisms to flucarbazone-sodium in wild oat (Avena fatua L.) from China.

Wild oat (Avena fatua L.) is a self-pollinating, allohexaploid species in the family Gramineae (grasses), which is a malignant weed that mainly harms crops such as wheat. In recent years, a decline in the control efficiency of flucarbazone-sodium against wild oat has occurred in some regions of China. We identified an ALS-resistant A. fatua population (R population). Whole-plant response assays revealed that the R population exhibited a moderate level of resistance (5.9-fold) to flucarbazone-sodium. Pre-treatment with malathion significantly reduced flucarbazone-sodium resistance in the R population. The known mutation sites and ALS gene relative expression that confer resistance to ALS inhibitor herbicides were not found in R population. Following flucarbazone-sodium treatment, the expression of eight genes related to metabolic enzymes was investigated using quantitative real-time PCR (qRT-PCR). CYP92A6 and the Aldo/keto reductase family were highly expressed in the R population after the application of flucarbazone-sodium. The mechanism of flucarbazone-sodium resistance in A. fatua is mediated by NTSR, nor TSR. Two genes, CYP92A6 and the Aldo/keto reductase family, were discovered to be possibly related in the metabolism of NTSR in the A. fatua population, justifying more functional studies. The results will serve as a data resource for further studies on the molecular mechanisms of A. fatua to flucarbazone-sodium.

Insecticide resistance and its intensity in urban Anopheles arabiensis in Kisumu City, Western Kenya: Implications for malaria control in urban areas.

The rise of insecticide resistance poses a growing challenge to the effectiveness of vector control tools, particularly in rural areas. However, the urban setting has received comparatively less focus despite its significance in attracting rural to urban migration. Unplanned urbanization, often overlooked, exacerbates insecticide resistance as Anopheles mosquitoes adapt to the polluted environments of rapidly expanding cities. This study aimed to assess the insecticide susceptibility status of malaria vectors and identify potential underlying mechanisms across three distinct ecological settings characterized by differing levels of urbanization in Kisumu County, Kenya. The study was conducted in 2022-2023 in Kisumu County, western Kenya. Field-derived An. gambiae (s.l.) larvae collected from a long stretch of urban-to-rural continuum were phenotyped as either resistant or susceptible to six different insecticides using the World Health Organization (WHO) susceptibility test. Polymerase chain reaction (PCR) techniques were used to identify the species of the An. gambiae complex and screened for mutations at voltage-gated sodium channels (Vgsc-1014F, Vgsc-1014S, Vgsc-1575Y) and acetylcholinesterase (Ace1) target site mutation 119S. Metabolic enzyme activities (non-specific β-esterases and monooxygenases) were evaluated in mosquitoes not exposed to insecticides using microplate assays. Additionally, during larval sampling, a retrospective questionnaire survey was conducted to determine pesticide usage by the local inhabitants. Anopheles arabiensis dominated in urban (96.2%) and peri-urban (96.8%) areas, while An. gambiae (s.s.) was abundant in rural settings (82.7%). Urban mosquito populations showed high resistance intensity to deltamethrin (Mortality rate: 85.2% at 10x) and suspected resistance to Pirimiphos-methyl and bendiocarb while peri-urban and rural populations exhibited moderate resistance intensity to deltamethrin (mortality rate >98% at 10x). Preexposure of mosquitoes to a synergist piperonyl butoxide (PBO) significantly increased mortality rates: from 40.7% to 88.5% in urban, 51.9% to 90.3% in peri-urban, and 55.4% to 87.6% in rural populations for deltamethrin, and from 41.4% to 78.8% in urban, 43.7% to 90.7% in peri-urban, and 35% to 84.2% in rural populations for permethrin. In contrast, 100% mortality to chlorfenapyr and clothianidin was observed in all the populations tested. The prevalence of L1014F mutation was notably higher in urban An. arabiensis (0.22) unlike the peri-urban (0.11) and rural (0.14) populations while the L1014S mutation was more prevalent in rural An. gambiae (0.93). Additionally, urban An. arabiensis exhibited elevated levels of mixed function oxidases (0.8/mg protein) and non-specific esterases (2.12/mg protein) compared to peri-urban (0.57/mg protein and 1.5/mg protein, respectively) and rural populations (0.6/mg protein and 1.8/mg protein, respectively). Pyrethroids, apart from their use in public health through LLINs, were being highly used for agricultural purposes across all ecological settings (urban 38%, peri-urban 36% and rural 37%) followed by amidine group, with organophosphates, neonicotinoids and carbamates being of secondary importance. These findings show high resistance of An. arabiensis to insecticides commonly used for vector control, linked with increased levels of detoxification enzymes. The observed intensity of resistance underscores the pressing issue of insecticide resistance in urban areas, potentially compromising the effectiveness of vector control measures, especially pyrethroid-treated LLINs. Given the species' unique behavior and ecology compared to An. gambiae, tailored vector control strategies are needed to address this concern in urban settings.

Influenza A virus shedding and reinfection during the post-weaning period in swine: longitudinal study of two nurseries

IntroductionInfluenza A virus in swine (IAV-S) is common in the United States commercial swine population and has the potential for zoonotic transmission.ObjectiveTo elucidate influenza shedding the domestic pig population, we evaluated two commercial swine farms in Illinois, United States, for 7 weeks. Farm 1 had a recent IAV-S outbreak. Farm 2 has had IAV-S circulating for several years.MethodsForty post-weaning pigs on Farm 1 and 51 pigs from Farm 2 were individually monitored and sampled by nasal swabs for 7 weeks.ResultsRT-PCR results over time showed most piglets shed in the first 2 weeks post weaning, with 91.2% shedding in week one, and 36.3% in week two. No difference in the number of pigs shedding was found between the two nurseries. Reinfection events did differ between the farms, with 30% of piglets on Farm 1 becoming reinfected, compared to 7.8% on Farm 2. In addition, whole genome sequencing of nasal swab samples from each farm showed identical viruses circulating between the initial infection and the reinfection periods. Sequencing also allowed for nucleic and amino acid mutation analysis in the circulating viruses, as well the identification of a potential reverse zoonosis event. We saw antigenic site mutations arising in some pigs and MxA resistance genes in almost all samples.ConclusionThis study provided information on IAV-S circulation in nurseries to aid producers and veterinarians to screen appropriately for IAV-S, determine the duration of IAV-S shedding, and predict the occurrence of reinfection in the nursery period.

Achieving thermostability of a phytase with resistance up to 100 °C.

The development of enzymes with high-temperature resistance up to 100 °C is of significant and practical value in advancing the sustainability of industrial production. Phytase, a crucial enzyme in feed industrial applications, encounters challenges due to its limited heat resistance. Herein, we employed rational design strategies involving the introduction of disulfide bonds, free energy calculation, and B-factor analysis based on the crystal structure of phytase APPAmut4 (1.90 Å), a variant with enhanced expression levels derived from Yersinia intermedia, to improve its thermostability. Among the 144 variants experimentally verified, 29 exhibited significantly improved thermostability with higher t1/2 values at 65 °C. Further combination and superposition led to APPAmut9 with an accumulation of 5 additional pairs of disulfide bonds and 6 single-point mutation sites, leading to an enhancement in its thermostability with a t1/2 value of 256.7 min at 65 °C, which was more than 75-fold higher compared to that of APPAmut4 (3.4 min). APPAmut9 exhibited a T50 value of 96 °C, representing a substantial increase of 40.9 °C compared to APPAmut4. Notably, approximately 70% of enzyme activity remained intact after exposure to boiling water at 100 °C for a holding period of 5 min. Significantly, these advantageous modifications were strategically positioned away from the catalytic pocket where enzymatic reactions occur to ensure minimal compromise on catalytic efficiency between APPAmut9 (11,500 ± 1,100 /mM/s) and APPAmut4 (12,300 ± 1,600 /mM/s). This study demonstrates the feasibility of engineering phytases with resistance to boiling using rational design strategies.

Genetic screening of α-thalassemia fusion gene using routine flow-through hybridization

ObjectiveThe fusion gene is a rare form of α-thalassemia. Patients carrying the fusion gene could be misdiagnosed as normal or -α4.2deletion by the conventional thalassemia detection methods. The aim of this study was to present the detection of fusion genes using routine flow-through hybridization, as well as to analyze hematological and molecular characteristics.MethodsSamples were collected at our hospital from January 2019 to January 2024. Common thalassemia mutations in the Chinese population were conducted by flow-through hybridization. Samples showing faint coloration at the -α4.2 mutation site on hybridization membrane were considered suspicious. Samples detected as suspicious for -α4.2deletion were rechecked by conventional Gap-PCR. Those samples suspected of having -α4.2deletions were finally confirmed with specific primers for Gap-PCR and Sanger sequencing.ResultsOf the 32,083 samples, 25 samples (0.08%) were detected as suspected of having -α4.2 deletion by flow-through hybridization. However, upon reevaluation wtih conventional Gap-PCR reagents capable of detecting -α4.2 deletion, all were found to be negative for the deletion. Specific primers for Gap-PCR were designed, and fusion gene fragments were amplified. DNA sequencing of the HBA gene showed a 7-base mutation corresponding to the α-thalassemia fusion gene. Among the 25 samples, 22 were heterozygous carriers. Three samples were combined: one with Hb QS, one with β-thalassemia, and one with Hb G-Honolulu.Most hematological indices and capillary electrophoresis results were in the normal reference range.ConclusionThe fusion gene was present in 0.08% of the population in the Guangzhou region of Guangdong province, southern China. Conventional genetic methods tend to misdiagnose the fusion gene but can be effectively screened with flow-through hybridization.

Molecular characterization and B-cell epitope analysis of the TSP11 gene in Echinococcus infection strains from Yunnan Province.

This study investigates the molecular intricacies of the transmembrane protein TSP11 gene in Echinococcus strains isolated from livestock and patients in Yunnan Province afflicted with Echinococcus granulosus (E. granulosus) between 2016 and 2020. Gene typing analysis of the ND1 gene revealed the presence of the G1 type, G5 type and untyped strains, constituting 52.4, 38.1 and 9.5%, respectively. The analysis of 42 DNA sequences has revealed 24 novel single nucleotide polymorphic sites, delineating 11 haplotypes, all of which were of the mutant type. Importantly, there were no variations observed in mutation sites or haplotypes in any of the hosts. The total length of the TSP11 gene's 4 exons is 762 bp, encoding 254 amino acids. Our analysis posits the existence of 6 potential B-cell antigenic epitopes within TSP11, specifically at positions 49-KSN-51, 139-GKRG-142, 162-DNG-164, 169-NGS-171, 185-DS-186 and 231-PPRFTN-236. Notably, these epitopes exhibit consistent presence among various intermediate hosts and haplotypes. However, further validation is imperative to ascertain their viability as diagnostic antigens for E. granulosus in the Yunnan Province.

Characteristic spatial and frequency distribution of mutations in SCN1A

BackgroundSCN1A is the most well-recognized and commonly mutated gene related to epilepsy. This study analyzed the characteristic spatial and frequency distributions of SCN1A mutations, aiming to provide important insight into the mutagenesis etiopathology of SCN1A-associated epilepsy.MethodsEpilepsy-associated SCN1A variants were retrieved from the SCN1A mutation database, the HGMD database, and literature reviews. The base substitutions, mutation frequencies in CpG dinucleotides, and spatial distributions of mutations in terms of exons and structural domains were analyzed.ResultsA total of 2621 SCN1A variants were identified in 5106 unrelated cases. The most common type was missense mutation, followed by frameshift mutations and splice site mutations. Among the missense mutations, transitions within CpG dinucleotides were much more recurrently identified than transitions within non-CpG dinucleotides, and the most common type was the G > A transition. Among the nonsense mutations, the most predominant type of single-base substitution was the C > T transition, among which 75.3% (235/312) were within CpG sites. The most common “hotspot” codons for missense mutations were codons 101, 946, and 1783; while for nonsense mutations it was codon 712. One-base deletion or insertion was the most common type of frameshift mutation, causing protein truncation. The three most common frameshift mutations were c.5536_5539delAAAC, c.4554dupA, and c.5010_5013delGTTT. Splice mutations were the most frequently identified in exon 4 with a hotspot site c.602 + 1G > A. The spatial distribution of missense mutations showed that exons 22 and 4 had the highest mutation density (111 and 84 mutations per 100 bp, respectively), and exon 12 had the lowest mutation density, with 4 mutations per 100 bp. Further distribution analysis of the protein domains revealed that missense mutations were more common in the pore region and voltage sensor (231 mutations per 100 amino acids, respectively), and the protein truncation mutations were distributed evenly among the domains.ConclusionsSCN1A mutations tend to cluster at distinct sites, depending on the characteristic CpG dinucleotides, exons, and functional domains. Higher mutation density in particular regions, such as exon 22 and exon 4, offers promising targets for therapeutic genetic interventions.

Variation and evolution analysis of SARS-CoV-2 using self-game sequence optimization

IntroductionThe evolution of SARS-CoV-2 has precipitated the emergence of new mutant strains, some exhibiting enhanced transmissibility and immune evasion capabilities, thus escalating the infection risk and diminishing vaccine efficacy. Given the continuous impact of SARS-CoV-2 mutations on global public health, the economy, and society, a profound comprehension of potential variations is crucial to effectively mitigate the impact of viral evolution. Yet, this task still faces considerable challenges.MethodsThis study introduces DARSEP, a method based on Deep learning Associates with Reinforcement learning for SARS-CoV-2 Evolution Prediction, combined with self-game sequence optimization and RetNet-based model.ResultsDARSEP accurately predicts evolutionary sequences and investigates the virus’s evolutionary trajectory. It filters spike protein sequences with optimal fitness values from an extensive mutation space, selectively identifies those with a higher likelihood of evading immune detection, and devises a superior evolutionary analysis model for SARS-CoV-2 spike protein sequences. Comprehensive downstream task evaluations corroborate the model’s efficacy in predicting potential mutation sites, elucidating SARS-CoV-2’s evolutionary direction, and analyzing the development trends of Omicron variant strains through semantic changes.ConclusionOverall, DARSEP enriches our understanding of the dynamic evolution of SARS-CoV-2 and provides robust support for addressing present and future epidemic challenges.

Mutations in the main antigenic sites of VP7 and VP8* from G3P[8] rotavirus a strains circulating in Brazil may impact immune evasion to rotavirus vaccination.

In the post-rotavirus (RVA) vaccination era, uncommon and zoonotic strains have emerged as causative agents of acute gastroenteritis in humans, including the equine-like G3P[8] strains. First identified in 2013, this strain has quickly spread worldwide, reaching the position of the most prevalent genotype in many countries, including Brazil. Here, we report full genotype characterization and phylogenetic analysis of two equine-like G3P[8] strains detected in Goiás, a state in the Cerrado biome of the Brazilian Midwestern region, during the year of 2019. The strains were detected in different socioeconomic and demographic contexts: GO-MR from an asymptomatic adult living in a rural traditional community and GO-H5 from a symptomatic child from the state capital, with access to safe drinking water and essential sanitation services. These strains also displayed different backbone constellations considering the NSP2 gene segment (G3-P [8]-I2-R2-C2-M2-A2-N2-T2-E2-H2 for GO-MR and G3-P[8]-I2-R2-C2-M2-A2-N1-T2-E2-H2 for GO-H5). Furthermore, significant mutations in the main epitope sites of the VP7 and VP8* proteins of the detected strains, and other Brazilian G3P[8] viruses, were found with the comparison to RV1 and RV5 vaccine proteins, indicating a potential ability of these viruses to evade vaccine protection, which may contribute to their prevalence both nationally and globally. In summary, this study corroborates the genetic diversity of equine-like G3P[8] DS-1-like strains circulating worldwide, highlights the epidemiological importance of adults as reservoirs of RVA and shows the substantial differences between these emerging strains and the currently used anti-RVA vaccines, which may partially explain their predominance due to potential evasion of vaccine-induced protection.

Examination of respiratory syncytial virus fusion protein proteolytic processing and roles of the P27 domain.

The respiratory syncytial virus (RSV) fusion protein (F) facilitates virus-cell membrane fusion, which is critical for viral entry, and cell-cell fusion. In contrast to many type I fusion proteins, RSV F must be proteolytically cleaved at two distinct sites to be fusogenic. Cleavage at both sites results in the release of a 27 amino-acid fragment, termed Pep27. We examined proteolytic processing and the role of Pep27 for RSV F from both RSV A2 and RSV B9320 laboratory-adapted strains, allowing important comparisons between A and B clade F proteins. F from both clades was cleaved at both sites, and pulse-chase analysis indicated that cleavage at both sites occurs early after synthesis, most likely within the secretory pathway. Mutation of either site to alter the furin recognition motif blocked cell-cell fusion activity. To assess the role of Pep27 in F processing and expression, we deleted the Pep27 fragment, but preserved the cleavage sites. Deletion of Pep27 reduced F surface expression and cell-cell fusion. Two conserved N-linked glycosylation sites within Pep 27 are present in both the RSV A2 and RSV B9320 F. Randomization of the Pep27 sequence, while conserving the two N-liked glycosylation sites, did not significantly change surface expression, and only modestly reduced cell-cell fusion. However, the disruption of either Pep27 glycosylation site reduced cell-cell fusion. This work clarifies the timing of RSV F proteolytic cleavage and offers insight into the crucial role the N-linked glycosylation sites within Pep27 play in the biological function of F.

N-glycosylation facilitates the activation of a plant cell-surface receptor.

Plant receptor kinases (RKs) are critical for transmembrane signalling involved in various biological processes including plant immunity. MALE DISCOVERER1-INTERACTING RECEPTOR-LIKE KINASE 2 (MIK2) is a unique RK that recognizes a family of immunomodulatory peptides called SERINE-RICH ENDOGENOUS PEPTIDEs (SCOOPs) and activates pattern-triggered immunity responses. However, the precise mechanisms underlying SCOOP recognition and activation of MIK2 remain poorly understood. Here we present the cryogenic electron microscopy structure of a ternary complex consisting of the extracellular leucine-rich repeat (LRR) of MIK2 (MIK2LRR), SCOOP12 and the extracellular LRR of the co-receptor BAK1 (BAK1LRR) at a resolution of 3.34 Å. The structure reveals that a DNHH motif in MIK2LRR plays a critical role in specifically recognizing the highly conserved SxS motif of SCOOP12. Furthermore, the structure demonstrates that N-glycans at MIK2LRRAsn410 directly interact with the N-terminal capping region of BAK1LRR. Mutation of the glycosylation site, MIK2LRRN410D, completely abolishes the SCOOP12-independent interaction between MIK2LRR and BAK1LRR and substantially impairs the assembly of the MIK2LRR-SCOOP12-BAK1LRR complex. Supporting the biological relevance of N410-glycosylation, MIK2N410D substantially compromises SCOOP12-triggered immune responses in plants. Collectively, these findings elucidate the mechanism underlying the loose specificity of SCOOP recognition by MIK2 and reveal an unprecedented mechanism by which N-glycosylation modification of LRR-RK promotes receptor activation.

Targeted RNA Sequencing of Head and Neck Adenoid Cystic Carcinoma Reveals SEC16A::NOTCH1 Fusion and MET Exon 14 Skipping as Potentially Actionable Alterations.

Adenoid cystic carcinoma (AdCC) of the head and neck harbors MYB/MYBL1::NFIB fusions in around 60% of cases, with unfavorable long-term survival due to frequent recurrences and metastases, currently lacking effective targeted therapy. The study aims to identify actionable alterations and to elucidate the molecular underpinnings of MYB/MYBL1::NFIB-negative AdCC using a large targeted RNA sequencing panel. We retrospectively searched our MSK-Solid Fusion clinical sequencing database for head and neck AdCC sequenced between2016and 2023. Of a total of 55 cases, 28 showed MYB::NFIB, 7 showed MYBL1::NFIB, and one case each harbored MYB::MPDZ (case 1) and FUS::MYB (case 2). One base of tongue tumor expressed both MYB::NFIB fusion and MET exon 14 skipping transcripts due to concurrent MET splice site mutation, D1010N (case 3). One parotid tumor lacked MYB/MYBL1 rearrangement but instead showed an in-frame SEC16A::NOTCH1 fusion that preserved the secretase cleavage site (case 4). Clinical records on 4cases with non-canonical sequencing findings were reviewed. Distant metastases were present at the initial diagnosis (case 2) or at recurrence (cases 1, 3, and 4). Disease-related mortality occurred in cases 2 and 4 despite radiotherapy and immunotherapy. The study improved the understanding of AdCC providing the first documentation of tumor clinical behavior associated with MYB::MPDZ and FUS::MYB fusions and reporting potentially actionable SEC16A::NOTCH1 fusion and MET exon 14 skipping mutation. Further research is needed to explore the therapeutic utility of MET inhibition and the efficacy of γ-secretase inhibitors against rare NOTCH1fusions in AdCC.

Juvenile hormone controls trehalose metabolism by regulating trehalase 2 activity in ovarian development of Helicoverpa armigera.

Trehalase (Treh) is crucial for ovarian development as it directly regulates the energy supply by hydrolyzing trehalose into glucose. Juvenile hormone (JH) is also essential for ovarian development, but how it affects Treh2 activity remains unclear. This study, which employed Helicoverpa armigera as a model, showed that HaTreh2 transcription and enzymatic activity peaks coincided with the peak of JH titers (the 2 and 3 days after emergence). Compared to the dsGFP control, knockdown of HaTreh2 transcription severely impaired ovarian development. LC-MS/MS and site mutation experiments demonstrated that JH triggered the serine 345 phosphorylation of HaTreh2 via the GPCR-cAMP-PKA pathway, thereby activating its enzymatic activity. Additionally, HaTreh2 is directly bound with trehalose transporter (HaTreT) under JH induction, thus controlling intracellular trehalose and glucose contents as well as the transcription of HaTreT. TreT controls the amount of trehalose, which serves as a substrate for Treh1, entering the cell. Treh2, on the other hand, uses extracellular trehalose as substrate, and the hydrolysis product glucose is further transported into the cell. Here, HaTreh2 regulated the substrate that HaTreh1 can act upon in the cell by directly binding with HaTreT during ovarian development when JH is induced. Therefore, JH systematically regulated trehalose metabolism during ovarian development through regulating the activity of HaTreh2. This study sheds light on the coordinated interplay between JH pathway and sugar metabolism in ovarian development.

Enhanced predictability and interpretability of COVID-19 severity based on SARS-CoV-2 genomic diversity: a comprehensive study encompassing four years of data.

Despite the end of the global Coronavirus Disease 2019 (COVID-19) pandemic, the risk factors for COVID-19 severity continue to be a pivotal area of research. Specifically, studying the impact of the genomic diversity of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) on COVID-19 severity is crucial for predicting severe outcomes. Therefore, this study aimed to investigate the impact of the SARS-CoV-2 genome sequence, genotype, patient age, gender, and vaccination status on the severity of COVID-19, and to develop accurate and robust prediction models. The training set (n = 12,038), primary testing set (n = 4,006), and secondary testing set (n = 2,845) consist of SARS-CoV-2 genome sequences with patient information, which were obtained from Global Initiative on Sharing all Individual Data (GISAID) spanning over four years. Four machine learning methods were employed to construct prediction models. By extracting SARS-CoV-2 genomic features, optimizing model parameters, and integrating models, this study improved the prediction accuracy. Furthermore, Shapley Additive exPlanes (SHAP) was applied to analyze the interpretability of the model and to identify risk factors, providing insights for the management of severe cases. The proposed ensemble model achieved an F-score of 88.842% and an Area Under the Curve (AUC) of 0.956 on the global testing dataset. In addition to factors such as patient age, gender, and vaccination status, over 40 amino acid site mutation characteristics were identified to have a significant impact on the severity of COVID-19. This work has the potential to facilitate the early identification of COVID-19 patients with high risks of severe illness, thus effectively reducing the rates of severe cases and mortality.

Genetic characterization of influenza B virus and oseltamivir resistance in pediatric patients with acute respiratory infections: a cross-sectional study.

Influenza virus neuraminidase inhibitors (NAIs) drug usage can result in NAI resistance, especially in children and individuals with weakened immune systems. The aim of the present study was to identify NAI-resistant variants of IBV and to introduce probable novel mutations, phylogenetic study, and its epitope mapping based on NA gene in patients from Shiraz, Iran. A cross-sectional study was conducted between 2017 and 2018 on symptomatic children. A real-time PCR was run for IBV screening. Then, making use of direct sequencing, amplified 1401 bases of NA gene and phylogenetic tree reconstructed. Epitopes were predicted using ABCpred server. From among a total of 235 specimens, 9.7% were identified with IBV infection. Of them, sequence of NA gene for 17 isolates were analyzed. Phylogenetic analysis showed that 15 isolates belonged to Yamagata clade 3 Wisconsin/01-like subclade and 2 were related to Victoria clade 1 Brisbane/60-like subclade (Vic-1A-2). NA gene sequence analysis showed a total of 52 substitutions in which 27 were for BVic and 37 were for BYam isolates and 19 were novel substitutions. Only one substitution (S198N) was found in NA active site and T49M, I120V, N198S, N219K, S295R, D320K N340D, E358K, D384G, and D463N were found as probable resistance variants to NAIs. Epitope mapping showed some major differences in our isolates NA gene. Present study was one of the rare comprehensive studies conducted in Shiraz/Iran on IBV resistant associated variants to NAIs. We reported 11.7% mutation in NA active site and some probable NAIs resistant mutations. Epitope mapping confirmed major changes in NA gene which needs broader studies to confirm.

Association between toxin-antitoxin system mutations and global transmission of MDR-TB.

The emergence of Multidrug-Resistant Tuberculosis (MDR-TB) poses a significant threat to global tuberculosis control efforts. This study aimed to examine the influence of mutations in Toxin-Antitoxin system genes on the global transmission of MDR-TB caused by Mycobacterium tuberculosis (M. tuberculosis). Whole-genome sequencing was conducted on 13,518 M. tuberculosis isolates. Genes of the Toxin-Antitoxin system were obtained from the National Center for Biotechnology Information (NCBI) Gene database. Techniques such as Random Forest, Gradient Boosting Decision Tree, and Generalized Linear Mixed Models were employed to identify mutation sites in Toxin-Antitoxin system-related genes that facilitated the transmission of MDR-TB. 4,066 (30.08%) were identified as MDR-TB strains of all analyzed isolates. We found significant associations between specific gene mutations and MDR-TB transmission clusters including mutations in Rv0298 (G213A), Rv1959c (parE1, C88T), Rv1960c (parD1, C134T), Rv1991A (maze, G156A), Rv2547 (vapB, C54G), Rv2862A (vapB23, T2C), and Rv3385c (vapB46, G70A). Additionally, several gene mutations associated with MDR-TB transmission clades such as Rv1956 (higA, G445T), Rv1960c (parD1, C134T), and Rv1962A (vapB35, G99A) were noted. Certain gene mutations including vapB35 (G99A), higA (G445T), and parD1 (C134T) correlated with cross-regional transmission clades. This study highlights the significant association between specific gene mutations in the Toxin-Antitoxin system and the global transmission of MDR-TB, providing valuable insights for developing targeted interventions to control MDR-TB.