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Molecular Biology and Evolution Jun 2024Segregation distorters (SDs) are genetic elements that distort the Mendelian segregation ratio to favor their own transmission and are able to spread even when they...
Segregation distorters (SDs) are genetic elements that distort the Mendelian segregation ratio to favor their own transmission and are able to spread even when they incur fitness costs on organisms carrying them. Depending on the biology of the host organisms and the genetic architecture of the SDs, the population dynamics of SDs can be highly variable. Inbreeding is considered an effective mechanism for inhibiting the spread of SDs in populations, and can evolve as a defense mechanism against SDs in some systems. However, we show that inbreeding in the form of selfing, in fact promotes the spread of SDs acting as pollen killers in a toxin-antidote system in hermaphroditic plants by two mechanisms: (1) By reducing the effective recombination rate between killer and antidote loci in two-locus systems and (2) by increasing the proportion of SD alleles in individual flowers, rather than in the general gene-pool. We also show that in rice (Oryza sativa L.), a typical hermaphroditic plant, all molecularly characterized SDs associated with pollen killing were involved in population hybridization and have introgressed across different species. Paradoxically, these loci, which are associated with hybrid incompatibility and can be thought of as Bateson-Dobzhansky-Muller incompatibility loci expected to reduce gene-flow between species, in fact cross species boundaries more frequently than random loci and may act as important drivers of introgression.
PubMed: 38935581
DOI: 10.1093/molbev/msae132 -
Plant Physiology Jun 2024Emerging evidence indicates that fatty acid (FA) metabolic pathways regulate host immunity to vertebrate viruses. However, information on FA signaling in plant virus...
Emerging evidence indicates that fatty acid (FA) metabolic pathways regulate host immunity to vertebrate viruses. However, information on FA signaling in plant virus infection remains elusive. In this study, we demonstrate the importance of fatty acid desaturase (FAD), an enzyme that catalyzes the rate-limiting step in the conversion of saturated FAs into unsaturated FAs, during infection by a plant RNA virus. We previously found that the rare Kua-ubiquitin conjugating enzyme (Kua-UEV1) fusion protein FAD4 from Nicotiana benthamiana (NbFAD4) was down-regulated upon turnip mosaic virus (TuMV) infection. We now demonstrate that NbFAD4 is unstable and is degraded as TuMV infection progresses. NbFAD4 is required for TuMV replication, as it interacts with TuMV replication protein 6K2 and colocalizes with viral replication complexes. Moreover, NbFAD4 overexpression dampened the accumulation of immunity-related phytohormones and FA metabolites, and its catalytic activity appears to be crucial for TuMV infection. Finally, a yeast two-hybrid library screen identified the vacuolar H+-ATPase component ATP6V0C as involved in NbFAD4 degradation and further suppression of TuMV infection. This study reveals the intricate role of FAD4 in plant virus infection, and shed lights on a new mechanism by which a V-ATPase is involved in plant antiviral defense.
PubMed: 38935533
DOI: 10.1093/plphys/kiae350 -
Military Medicine Jun 2024Low back pain (LBP) is highly prevalent after lower limb amputation (LLA) and contributes to substantial reductions in quality of life and function. Towards...
INTRODUCTION
Low back pain (LBP) is highly prevalent after lower limb amputation (LLA) and contributes to substantial reductions in quality of life and function. Towards understanding pathophysiological mechanisms underlying LBP after LLA, this article compares lumbar spine pathologies and muscle morphologies between individuals with LBP, with and without LLA.
MATERIALS AND METHODS
We queried electronic medical records of Service members with and without LLA who sought care for LBP at military treatment facilities between January 2002 and May 2020. Two groups with cLBP, one with (n = 15) and one without unilateral transtibial LLA (n = 15), were identified and randomly chosen from a larger sample. Groups were matched by age, mass, and sex. Lumbar muscle morphology, Pfirrmann grades, Modic changes, facet arthrosis, Meyerding grades, and lordosis angle were determined from radiographs and magnetic resonance images available in the medical record. Independent t-tests compared variables between cohorts while multiple regression models determined if intramuscular fat influenced Pfirrmann grades. Chi-square determined differences in presence of spondylolysis and facet arthrosis.
RESULTS
Lordosis angle was larger with LLA (P = 0.01). Spondylolysis was more prevalent with LLA (P = 0.008; 40%) whereas facet arthrosis was similar between cohorts (P = 0.3). Muscle area was not different between cohorts, yet intramuscular fat was greater with LLA (P ≤ 0.05). Intramuscular fat did not influence Pfirrmann grades (P > 0.15).
CONCLUSIONS
Despite similar lumbar muscle size, those with unilateral LLA may be predisposed to progress to symptomatic spondylolisthesis and intramuscular fat. Surgical and/or rehabilitation interventions may mitigate long-term effects of diminished spinal health, decrease LBP-related disability, and improve function for individuals with LLA.
PubMed: 38935402
DOI: 10.1093/milmed/usae306 -
Journal of Clinical Microbiology Jun 2024In this study, we investigated the genomic changes in a major methicillin-resistant (MRSA) clone following a significant outbreak at a hospital. Whole-genome sequencing...
In this study, we investigated the genomic changes in a major methicillin-resistant (MRSA) clone following a significant outbreak at a hospital. Whole-genome sequencing of MRSA isolates was utilized to explore the genomic evolution of post-outbreak MRSA strains. The epidemicity of the clone declined over time, coinciding with the introduction of multimodal infection control measures. A genome-wide association study (GWAS) identified multiple genes significantly associated with either high or low epidemic success, indicating alterations in mobilome, virulence, and defense mechanisms. Random Forest models pinpointed a gene related to fibrinogen binding as the most influential predictor of epidemicity. The decline of the MRSA clone may be attributed to various factors, including the implementation of new infection control measures, single nucleotide polymorphisms accumulation, and the genetic drift of a given clone. This research underscores the complex dynamics of MRSA clones, emphasizing the multifactorial nature of their evolution. The decline in epidemicity seems linked to alterations in the clone's genetic profile, with a probable shift towards decreased virulence and adaptation to long-term carriage. Understanding the genomic basis for the decline of epidemic clones is crucial to develop effective strategies for their surveillance and management, as well as to gain insights into the evolutionary dynamics of pathogen genomes.
PubMed: 38934681
DOI: 10.1128/jcm.00203-24 -
Microbiology Spectrum Jun 2024, an organism recently classified within the Pseudomonadaceae family, has been detected in diverse sources such as human tissues, animal guts, industrial fermenters, and...
, an organism recently classified within the Pseudomonadaceae family, has been detected in diverse sources such as human tissues, animal guts, industrial fermenters, and decomposition environments, suggesting a diverse ecological role. However, a large knowledge gap exists in how functions. In this comparative genomic analysis, adaptations indicative of habitat specificity among strains and genomic similarity to known opportunistic pathogens are revealed. Genomic investigation reveals a core metabolic utilization of multiple oxidative and non-oxidative catabolic pathways, suggesting adaptability to varied environments and carbon sources. The genomic repertoire of includes secondary metabolites, such as antimicrobials and siderophores, indicative of its involvement in microbial competition and resource acquisition. Additionally, the presence of transposases, prophages, plasmids, and Clustered Regularly Interspaced Short Palindromic Repeats-Cas systems in genomes suggests mechanisms for horizontal gene transfer and defense against viral predation. This comprehensive genomic analysis expands our understanding on the ecological functions, community interactions, and potential virulence of , while emphasizing its adaptability and diverse capabilities across environmental and host-associated ecosystems.IMPORTANCEAs the microbial world continues to be explored, new organisms will emerge with beneficial and/or pathogenetic impact. is a species originally isolated from clinical human tissue and fluid samples but has not been attributed to disease. Since its classification, has been found in animal guts, animal waste, decomposing remains, and biogas fermentation reactors. This is the first study to provide an in-depth view of the metabolic potential of publicly available genomes belonging to this species through a comparative genomics and draft pangenome calculation approach. It was found that is metabolically versatile and likely adapts to diverse energy sources and environments, which may make it useful for bioremediation and in industrial settings. A range of virulence factors and antibiotic resistances were also detected, suggesting may operate as an undescribed opportunistic pathogen.
PubMed: 38934605
DOI: 10.1128/spectrum.04157-23 -
Scandinavian Journal of Child and... Jan 2024The experience of several adverse childhood experiences (ACEs) has been shown to be associated with Post-Traumatic Stress Disorder (PTSD) and Disturbances in...
BACKGROUND
The experience of several adverse childhood experiences (ACEs) has been shown to be associated with Post-Traumatic Stress Disorder (PTSD) and Disturbances in Self-Organization (DSO) symptoms among adolescents. Defense mechanisms and coping styles are psychological processes involved in the association of ACEs with PTSD and DSO symptoms. However, there is a lack of research on the joint association of these variables among Faroese adolescents.
AIM
The aim of this study was to analyze the effect of exposure to ACEs on PTSD and DSO symptoms trough the indirect effect of defense mechanisms and coping styles in a sample of Faroese adolescents.
METHOD
Six hundred and eighty-seven Faroese adolescents were recruited from 19 schools. Participants responded to validated self-report questionnaires. A multiple step mediation and a serial mediation methodology were conducted through structural equation modeling.
RESULTS
Exposure to ACEs was linked to PTSD and DSO symptoms through the indirect effect of immature defense mechanisms, emotional coping, and detachment coping. Exposure to ACEs was linked to PTSD symptoms through rational coping.
CONCLUSIONS
The results suggest a mutual relationship between defense mechanisms and coping styles in coping with multiple adversity among adolescents.
PubMed: 38933756
DOI: 10.2478/sjcapp-2024-0004 -
Frontiers in Genome Editing 2024Rice, a staple food for a significant portion of the global population, faces persistent threats from various pathogens and pests, necessitating the development of... (Review)
Review
Rice, a staple food for a significant portion of the global population, faces persistent threats from various pathogens and pests, necessitating the development of resilient crop varieties. Deployment of resistance genes in rice is the best practice to manage diseases and reduce environmental damage by reducing the application of agro-chemicals. Genome editing technologies, such as CRISPR-Cas, have revolutionized the field of molecular biology, offering precise and efficient tools for targeted modifications within the rice genome. This study delves into the application of these tools to engineer novel alleles of resistance genes in rice, aiming to enhance the plant's innate ability to combat evolving threats. By harnessing the power of genome editing, researchers can introduce tailored genetic modifications that bolster the plant's defense mechanisms without compromising its essential characteristics. In this study, we synthesize recent advancements in genome editing methodologies applicable to rice and discuss the ethical considerations and regulatory frameworks surrounding the creation of genetically modified crops. Additionally, it explores potential challenges and future prospects for deploying edited rice varieties in agricultural landscapes. In summary, this study highlights the promise of genome editing in reshaping the genetic landscape of rice to confront emerging challenges, contributing to global food security and sustainable agriculture practices.
PubMed: 38933684
DOI: 10.3389/fgeed.2024.1415244 -
Antibody Therapeutics Apr 2024The recent discovery of public antibodies targeting -encoded repetitive interspersed families of polypeptides (RIFINs), which contain extracellular immunoglobulin-like... (Review)
Review
The recent discovery of public antibodies targeting -encoded repetitive interspersed families of polypeptides (RIFINs), which contain extracellular immunoglobulin-like domains from LAIR1 or LILRB1, constitutes a significant step forward in comprehending the reactivity of the parasite. These antibodies arise from unique B cell clones and demonstrate extensive cross-reactivity through their interaction with RIFINs. LAIR1 and LILRBs are specialized type I transmembrane glycoproteins, classified as immune inhibitory receptors, restricted to primates and mainly found on hematopoietic cells. They are instrumental in modulating interactions within the tumor microenvironment and across the immune system, and are increasingly recognized as important in anti-cancer immunotherapy and pathogen defense. The presence of LAIR1/LILRB1-containing antibodies offers new insights into malaria parasite evasion strategies and the immune system's response. Additionally, the innovative method of integrating extra exons into the antibody switch region is a noteworthy advancement, enriching the strategies for the generation of a varied array of bispecific and multispecific antibodies.
PubMed: 38933531
DOI: 10.1093/abt/tbae008 -
Regenerative Biomaterials 2024Cancer is one of the most challenging diseases in the world. Recently, iron oxide nanoparticles (IONPs) are emerging materials with rapid development and high...
Cancer is one of the most challenging diseases in the world. Recently, iron oxide nanoparticles (IONPs) are emerging materials with rapid development and high application value, and have shown great potential on tumor therapy due to their unique magnetic and biocompatible properties. However, some data hint us that IONPs were toxic to normal cells and vital organs. Thus, more data on biosafety evaluation is urgently needed. In this study, we compared the effects of silicon-coated IONPs (Si-IONPs) on two cell types: the tumor cells (Hela) and the normal cells (HEK293T, as 293 T for short), compared differences of protein composition, allocation and physical characteristics between these two cells. The major findings of our study pointed out that 293 T cells death occurred more significant than that of Hela cells after Si-IONPs treatment, and the rate and content of endocytosis of Si-IONPs in 293 T cells was more prominent than in Hela cells. Our results also showed Si-IONPs significant promoted the production of reactive oxygen species and disturbed pathways related to oxidative stress, iron homeostasis, apoptosis and ferroptosis in both two types of cells, however, Hela cells recovered from these disturbances more easily than 293 T. In conclusion, compared with Hela cells, IONPs are more likely to induce 293 T cells death and Hela cells have their own unique mechanisms to defense invaders, reminding scientists that future in vivo and in vitro studies of nanoparticles need to be cautious, and more safety data are needed for further clinical treatment.
PubMed: 38933085
DOI: 10.1093/rb/rbae065 -
Frontiers in Microbiology 2024Rice blast, a prevalent and highly destructive rice disease that significantly impacts rice yield, is caused by the rice blast fungus. In the present study, a strain...
Rice blast, a prevalent and highly destructive rice disease that significantly impacts rice yield, is caused by the rice blast fungus. In the present study, a strain named MTC-8, identified as , was demonstrated has strong antagonistic activity against the rice blast fungus, , and . The potential biocontrol agents were identified using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis and chromatography. Further investigations elucidated the inhibitory mechanism of the isolated compound and demonstrated its ability to suppress spore germination, alter hyphal morphology, disrupt cell membrane integrity, and induce defense-related gene expression in rice. MTC-8 promoted plant growth and may lead to the development of a biocontrol agent that meets agricultural standards. Overall, the MTC-8 strain exerted beneficial effects on plant growth, immunity and disease resistance against rice blast fungus. In this study, we isolated and purified a bioactive substance from fermentation broth, and the results provide a foundation for the development and application of biopesticides. Elucidation of the inhibitory mechanism against rice blast fungus provides theoretical support for the identification of molecular targets. The successful development of a biocontrol agent lays the groundwork for its practical application in agriculture.
PubMed: 38933037
DOI: 10.3389/fmicb.2024.1422476