Biology subjects

Gonzalez, R.

Publications and source records attributed to Gonzalez, R..

At least 37 records · Page 2Linked to original sources

bioRxiv2024

Experimental evolution of an RNA virus in Caenorhabditis elegans

The discovery of Orsay virus (OrV), the first virus infecting wild populations of Caenorhabditis elegans, has boosted studies of viral immunity pathways in this nematode. Considering the many advantages that C. elegans offers for fundamental research in host-pathogen interactions, this pathosystem has high potential to become a model system for experimental virus evolution studies. However, the evolutionary constraints operating in this pathosystem have barely been explored. Here we describe for the first time an evolution experiment of two different OrV strains in C. elegans. After 10 serial passages of evolution, we report slight changes in infectivity and non-synonymous mutations fixed in the evolved viral populations. In addition, we observed numerous minor variants emerging in the viral population. These minor variants were not randomly distributed along the genome but concentrated in polymorphic genomic regions. Overall, our work established the grounds for future experimental virus evolution studies using Caenorhabditis nematodes. HIGHLIGHTSO_LICaenorhabditis elegans-Orsay virus is a convenient pathosystem to study virus evolution. C_LIO_LIThe approach used to test the viral strains may interfere with the infection phenotypes observed. C_LIO_LIThere may be specific genomic hotspots regions of nucleotide diversity important for the evolution of Orsay virus. C_LIO_LIThe substitution rate observed for Orsay virus was low, suggesting that the two strains studied might be already well adapted to laboratory conditions. C_LI

evolutionary biology↗

bioRxiv2023

Within-host virus spreading and tolerance to infection are key factors of the Arabidopsis thaliana age-dependent susceptibility to viral infections

Arabidopsis thaliana is more susceptible to certain viruses during its later developmental stages. The reasons for this age-dependent susceptibility are not fully understood. Here we explored the possible causes by studying the A. thaliana infection response to turnip mosaic virus at three developmental stages: vegetative, bolting and flowering. We found that infected plants at later stages downregulate cell wall fortification genes and that this downregulation facilitates the viral spread and systemic infection. Despite being more susceptible to infection, infected flowering plants are more fertile (i.e., produce more viable seeds) than vegetative and bolting infected plants; that is, they have greater fitness than plants infected at these earlier developmental stages. Treatment of postbolting plants with salicylic acid increases resistance to infections at the cost of significantly reducing fertility. Together, these observations suggest a negative trade-off between viral susceptibility and plant fertility. Our findings point towards a development-dependent tolerance to infection.

microbiology↗

bioRxiv2023

Natural monobacterial environments modulate viral infection in Caenorhabditis elegans

The microbes associated with an organism play a pivotal role in modulating their host susceptibility to viral infections. However, the influence of individual microbes on viral infections is not well understood. Here, we examined the impact of 67 naturally bacterial associates on Caenorhabditis elegans susceptibility to Orsay virus. Our findings reveal that viral infection of C. elegans is significantly influenced by monobacterial environments. The majority of tested natural bacterial environments reduced C. elegans viral infection while some increased susceptibility compared to an Escherichia coli environmental reference. The reduction in viral infection is not caused by degradation of the virions or poor nutrition of C. elegans by the bacteria. The reduction in viral infection does not require known antiviral responses, including RNA interference and transcriptional regulation downstream of the RIG-I homolog DRH-1. However, one bacterium, Lelliottia JUb276, reduced susceptibility but does not induce resistance to viral infection in drh-1 mutants. Our research underscores the importance of considering the natural biotic environment in studies of viral infections and provides insights for future research on host-microbes-virus interactions and viral immunity. AUTHOR CONTRIBUTIONSConceptualization: RG, MAF; Formal analysis: RG; Investigation: RG; Resources: MAF; Data Curation: RG; Writing - Original Draft: RG, MAF; Writing - Review & Editing: RG, MAF; Visualization: RG; Supervision: MAF; Project administration: RG, MAF; Funding acquisition: RG, MAF.

microbiology↗

bioRxiv2022

A globally distributed major virus-resistance association in Arabidopsis thaliana

Plant viruses account for enormous agricultural losses worldwide, and the most effective way to combat them is to identify genetic material conferring plant resistance to these pathogens. Aiming to identify genetic associations with responses to infection, we screened a large panel of Arabidopsis thaliana natural inbred lines for four disease-related traits caused by infection by A. thaliana-naive and -adapted isolates of the natural pathogen turnip mosaic virus (TuMV). We detected a strong, replicable association in a 1.5 Mb region on chromosome 2 with a 10-fold increase in relative risk of systemic necrosis. The region contains several plausible causal genes as well as abundant structural variation, including an insertion of a Copia transposon into a Toll/interleukin receptor (TIR-NBS-LRR) coding for a gene involved in defense, that could be either a driver or a consequence of the disease-resistance locus. When inoculated with TuMV, loss-of-function mutant plants of this gene exhibited different symptoms than wild-type plants. The direction and severity of symptom differences depended on the adaptation history of the virus. This increase in symptoms severity was specific for infections with the adapted isolate. Necrosis-associated alleles are found worldwide, and their distribution is consistent with a trade-off between resistance during viral outbreaks and a cost of resistance otherwise, leading to negative frequency-dependent selection.

genetics↗

bioRxiv2022

Acculturative orientations among Hispanic/Latinx caregivers in the ABCD Study: Associations with caregiver and youth mental health and youth brain function

BackgroundPopulation-based neuroscience offers opportunities to examine important but understudied sociocultural factors, such as acculturation. Acculturation refers to the extent to which an individual retains their cultural heritage and / or adopts the receiving societys culture and is particularly salient among Hispanic/Latinx immigrants. Specific acculturative orientations have been linked to vulnerability to substance use, depression, and suicide and are known to influence family dynamics between caregivers and their children. MethodsWe investigated first- and second-generation Hispanic/Latinx caregivers in the ABCD Study and examined how caregivers acculturative orientation impacts their mental health, as well as the mental health of their children. In addition, we evaluated how caregiver orientation is associated with adolescent socio-affiliative neural function in the ventromedial prefrontal cortex, insula, and temporoparietal junction. ResultsWe identified two caregiver acculturation profiles: bicultural (retains heritage culture while adopting US culture) and detached (discards heritage culture and rejects US culture). Bicultural caregivers exhibited fewer symptoms of depression, avoidant behaviors, and inattention compared to detached caregivers; further, youth exhibited similar internalizing effects across caregiver profiles. Moreover, youth with bicultural caregivers displayed increased resting-state brain activity in the left insula; however, differences in long-range functional connectivity were not significant. ConclusionsCaregiver acculturation is an important familial-environmental factor in Hispanic/Latinx families linked to significant differences in caregiver and youth mental health and youth insula activity. Future work should examine sociocultural and neurodevelopmental changes across adolescence to assess health outcomes and determine whether localized, corticolimbic brain effects are ultimately translated into long-range connectivity differences.

neuroscience↗

bioRxiv2022

Host age-dependent evolution of a plant RNA virus

Viruses are obligate pathogens that entirely rely on their host resources to complete their infectious cycle. The availability of such resources depends upon external and internal factors, being host age one of the most relevant ones. The interplay between host age and virus evolution has not been thoroughly studied in plants. Here, we have used the Arabidopsis thaliana - turnip mosaic virus (TuMV) pathosystem to study plant-virus interactions and virus evolution at three different host ages: vegetative (juvenile), bolting (transition) and reproductive (mature) stages. After infecting plants with a naive and a well-adapted TuMV isolates, we observed that the older the host the faster and more severe the infections were. The same trend was observed for several other viruses. Thereafter, we experimentally evolved lineages of the naive and the well-adapted TuMV isolates in plants from each of the three developmental stages. All evolved viruses enhanced their infection phenotypes, being this increase more intense on viruses evolved in younger hosts. The genomic changes of the evolved viral lineages revealed mutation patterns that strongly depended on the founder viral isolate as well as on the age of the host wherein the lineages evolved.

evolutionary biology↗

bioRxiv2022

Cell-free prototyping enables implementation of optimized reverse beta-oxidation pathways in heterotrophic and autotrophic bacteria

Carbon-negative synthesis of biochemical products has the potential to mitigate global CO2 emissions. An attractive route to do this is the reverse {beta}-oxidation (r-BOX) pathway coupled to the Wood-Ljungdahl pathway. Here, we optimized and implemented r-BOX for the synthesis of C4-C6 acids and alcohols. With a high-throughput in vitro prototyping workflow, we screened 762 unique pathway combinations using cell-free extracts tailored for r-BOX to identify enzyme sets for enhanced product selectivity. Implementation of these pathways into Escherichia coli generated designer strains for the selective production of butanoic acid (4.9 {+/-}0.1 gL-1), hexanoic acid (3.06 {+/-} 0.03 gL-1) and 1-hexanol (1.0 {+/-} 0.1 gL-1) at the best performance reported to date in this bacterium. We also generated Clostridium autoethanogenum strains able to produce 1-hexanol from syngas, achieving a titer of 0.26 gL-1 in a 1.5-L continuous fermentation. Our strategy enables optimization of rBOX derived products for biomanufacturing and industrial biotechnology.

synthetic biology↗

bioRxiv2021

Discovery of cell active macrocyclic peptides with on-target inhibition of KRAS signaling

RAS is the most commonly mutated oncogene in human cancers and RAS-driven tumors are amongst the most difficult to treat. Historically, discovery of therapeutics targeting this protein has proven challenging due to a lack of deep hydrophobic pockets to which a small molecule might bind. The single such pocket available is normally occupied by GDP or GTP which have millimolar cellular concentrations and picomolar affinities for KRAS and hence is challenging to target. The recent FDA approval of sotorasib, a covalent modifier of the KRASG12C mutant protein, has clinically validated KRAS as an oncology target. However, traditional challenges remain for targeting the more common KRAS mutations such as G12D and G12V. As an alternative approach, we investigated the superior binding capacity of macrocyclic peptides to identify KRAS inhibitory molecules. We focused on the recently reported disulfide-cyclized arginine-rich peptide KRpep-2d, discovered through phage display and previously independently confirmed by us as a bona fide KRAS binder. To mitigate intracellular disulfide reduction and loss of binding, we identified an alternate cyclization motif by inverting the configuration of Cys5 and linking it to Cys15 through a thioacetal bridge. The corresponding peptide bound KRAS through cis isomerization of the peptide bond between D-Cys5 and Pro6 as observed through x-ray crystallography. Prototypic molecules displayed measurable cellular inhibition of RAS signaling without membrane lysis and counter-screen off-target activity. An analogue containing azido-lysine confirmed the cell penetrant nature of this molecule using our recently reported NanoClick assay. To improve cellular activity, we sought to improve proteolytic stability. Structure-activity relationship studies identified key scaffold residues critical for binding and revealed that replacement of N- and C-terminal arginine residues with D-arginines and introduction of an -methyl moiety at Ser10 resulted in a molecule with improved proteolytic stability as indicated by its persistence in whole cell homogenate. The resulting peptide MP-3995 had improved and sustained cell-based efficacy. On-target activity was validated through confirmation of target engagement, lack of signaling in irrelevant pathways, and use of non-binding control peptides. Mechanism of action studies suggested that peptide binding to both GDP- and GTP-states of KRAS may contribute to cellular activity. Although validated as bona fide and on-target inhibitors of cell based KRAS signaling, this series is unlikely to advance to the clinic in its current form due to its arginine-dependent cell entry mechanism. Indeed, we showed a strong correlation between net positive charge and histamine release in an ex vivo assay making this series challenging to study in vivo. Nonetheless, these molecules provide valuable templates for further medicinal chemistry efforts aimed at leveraging this unique inhibitory binding site on KRAS. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=118 SRC="FIGDIR/small/459913v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@17f4764org.highwire.dtl.DTLVardef@12818daorg.highwire.dtl.DTLVardef@177bdf0org.highwire.dtl.DTLVardef@57046c_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2021

Predictive evolution of metabolic phenotypes using model-designed selection niches

Traits lacking fitness benefit cannot be directly selected for under Darwinian evolution. Thus, features such as metabolite secretion are currently inaccessible to adaptive laboratory evolution. Here, we utilize environment-dependency of trait correlations to enable Darwinian selection of fitness-neutral or costly traits. We use metabolic models to design selection niches and to identify surrogate traits that are genetically correlated with cell fitness in the selection niche but coupled to the desired trait in the target niche. Adaptive evolution in the selection niche and subsequent return to the target niche is thereby predicted to enhance the desired trait. We experimentally validate the theory by evolving Saccharomyces cerevisiae for increased secretion of aroma compounds in wine fermentation. Genomic, transcriptomic, and proteomic changes in the evolved strains confirmed the predicted flux re-routing to aroma biosynthesis. The use of model-designed selection niches facilitates the predictive evolution of fitness-costly traits for ecological and biotechnological applications.

systems biology↗

bioRxiv2021

A G protein-coupled receptor is required in cartilaginous and dense connective tissues to maintain spine alignment

Adolescent idiopathic scoliosis (AIS) is the most common spine disorder affecting children worldwide, yet little is known about the pathogenesis of this disorder. Here, we demonstrate that genetic regulation of structural components of the axial skeleton, the intervertebral discs and dense connective tissues (e.g., ligaments and tendons), are essential for maintenance of spinal alignment. We show that the G-coupled protein receptor Adgrg6, previously implicated in human AIS association studies, is required in these tissues to maintain typical spine morphology. We show that Adgrg6 regulates biomechanical properties of tendon and stimulates CREB signaling governing gene expression in cartilaginous tissues of the spine. Treatment with an cAMP agonist was able to mirror aspects of receptor function in culture defining core pathways for regulation of these axial connective tissues. As ADGRG6 is a key gene involved in human AIS, these findings open up novel therapeutic opportunities for human scoliosis. HighlightsO_LIKnockout mice lacking Adgrg6 function in the tendons and ligaments of the spine develop perinatal-onset thoracic scoliosis. C_LIO_LILoss of Adgrg6 function in cartilaginous tissues of the discs contribute to the incidence and severity of scoliosis. C_LIO_LIThe loss of Adgrg6 function in spine tissues provide a model of construct validity for human adolescent idiopathic scoliosis C_LIO_LIFine tuning of the biomechanical properties of dense connective tissues is essential for maintaining spine alignment. C_LI

developmental biology↗

bioRxiv2021

p53 pro-apoptotic activity is regulated by the G2/M promoting factor Cdk1 in response to DNA damage

Exposure to genotoxic stress promotes cell-cycle arrest and DNA repair or apoptosis. These "life" or "death" cell fate decisions often rely on the activity of the tumor suppressor gene p53. Therefore, how p53 activity is precisely regulated is essential to maintain tissue homeostasis and to prevent cancer development. Here we demonstrate that Drosophila p53 pro-apoptotic activity is regulated by the G2/M kinase Cdk1. We find that cell cycle arrested or endocycle-induced cells are refractory to ionizing radiation induced apoptosis. We show that the p53 protein is not able to bind to and to activate the expression of the pro-apoptotic genes in experimentally arrested cells. Our results indicate that p53 genetically and physically interacts with Cdk1 and that p53 pro-apoptotic role is regulated by the cell cycle status of the cell. We propose a model in which cell cycle progression and p53 pro-apoptotic activity are molecularly connected to coordinate the appropriate response after DNA damage.

developmental biology↗

bioRxiv2020

Arabidopsis thaliana genes contributing to differences in the outcome of infection with generalist and specialist strains of Turnip mosaic virus identified by genome-wide association studies

Pathogens can be classified as generalists or specialists depending on their host breadth. While generalists are able to successfully infect a wide variety of host species, the host range of specialists is limited to a few related species. Even though generalists seem to gain an advantage due to their wide host range, they usually pay a cost in terms of fitness within each host species (i.e., the jack-of-all trades, master of none). On the contrary, specialists have high fitness within their own host. A highly relevant yet poorly explored question is whether generalist and specialist viruses differ in the way they interact with their hosts gene expression networks. To identify host genetic factors relevant for the infection of specialist or generalist viruses, we undertook a genome-wide association study (GWAS) approach. Four hundred fifty natural accessions of Arabidopsis thaliana were inoculated with turnip mosaic potyvirus strains that were either generalist (TuMV-G) or specialist (TuMV-S). Several disease-related traits have been associated with different sets of host genes for each TuMV strain. While most of the mapped loci were traitor strain-specific, one shared locus was mapped for both strains, a disease resistance TIR-NBS-LRR class protein. Likewise, only one locus was found involved in more than one of the disease-related traits evaluated, a putative cysteine-rich receptor-like protein kinase 20. To validate these results, the corresponding null mutant plants were inoculated with TuMV-G or -S and the outcome of infection was characterized. Author summaryGeneralist and specialist viruses are commonly found in nature, where they have potential for epidemics, and are classified depending on their host breath. In this study we used a genome-wide association study to characterize differences in the genetic basis of both infection strategies from a host perspective. Our experimental setup consisted of 450 accessions of A. thaliana and two strains of TuMV. We found differences in the number of associated genes and their functions in disease-related traits. Results were validated by characterization of viral infections in null mutant plants deficient for a set of the identified genes.

evolutionary biology↗

bioRxiv2020

Deep neural network models reveal interplay of peripheral coding and stimulus statistics in pitch perception

Perception is thought to be shaped by the environments for which organisms are optimized. These influences are difficult to test in biological organisms but may be revealed by machine perceptual systems optimized under different conditions. We investigated environmental and physiological influences on pitch perception, whose properties are commonly linked to peripheral neural coding limits. We first trained artificial neural networks to estimate fundamental frequency from biologically faithful cochlear representations of natural sounds. The best-performing networks replicated many characteristics of human pitch judgments. To probe the origins of these characteristics, we then optimized networks given altered cochleae or sound statistics. Human-like behavior emerged only when cochleae had high temporal fidelity and when models were optimized for naturalistic sounds. The results suggest pitch perception is critically shaped by the constraints of natural environments in addition to those of the cochlea, illustrating the use of artificial neural networks to reveal underpinnings of behavior.

animal behavior and cognition↗

bioRxiv2020

Neural vulnerability and hurricane-related media predict posttraumatic stress in youth

As natural disasters increase in frequency and severity1, 2, mounting evidence reveals that their human toll extends beyond death, injury, and loss. Posttraumatic stress (PTS) can be common among directly exposed individuals, and children are particularly vulnerable3, 4. Curiously, PTS can even be found among youth far removed from harms way, and media-based exposure may partially account for this phenomenon5-8. Unfortunately, susceptibility to media effects has been difficult to characterize because most research is initiated post-event, precluding examination of pre-disaster factors. In this study, we mitigate this issue with data from nearly 400 9-to 11-year-old children collected prior to and after Hurricane Irma. We evaluate whether preexisting neural patterns moderate associations between hurricane experiences and later Irma-related PTS. We show that "dose" of both objective exposure and Irma-related media exposure predicted Irma-related PTS, the latter even among children dwelling thousands of kilometers away from the hurricane. Furthermore, we show, using pre-hurricane functional magnetic resonance imaging data, that neural responses in brain regions associated with anxiety and stress confer particular vulnerability to the psychological effects of hurricane exposure among certain children. Surprisingly, this was even the case for media exposure- we found that that right amygdala reactivity to fearful stimuli moderated the association between Irma-related media exposure and PTS symptoms, with the media-PTS association strongest for children showing pre-hurricane heightened amygdala reactivity to Fear vs Neutral Faces. In contrast, in bilateral orbitofrontal cortex and left parahippocampal gyrus, children showing a weak response to the Fear condition relative to the Neutral condition were especially susceptible to PTS as a result of Irma-related media exposure. Collectively, these findings run counter to outdated "bullseye" models of disaster exposure that assume negative effects are narrowly circumscribed around a disasters geographic epicenter9. In contrast, for some youth with measurable preexisting vulnerability, consumption of extensive disaster-related media appears to offer an alternative pathway to disaster exposure that transcends geography and objective risk. This preventable exposure should be considered in disaster-related mental health efforts.

neuroscience↗

bioRxiv2020

Postembryonic screen for mutations affecting spine development in zebrafish

The spinal vertebral column gives structural support for the adult body plan, protects the spinal cord, and provides muscle attachment and stability, which allows the animal to move within its environment. The development and maturation of the spine and its physiology involve the integration of multiple musculoskeletal tissues including bone, cartilage, and fibrocartilaginous joints, as well as innervation and control by the nervous system. One of the most common disorders of the spine in human is adolescent idiopathic scoliosis (AIS), which is characterized by the onset of an abnormal lateral curvature of the spine of <10{degrees} around adolescence, in otherwise healthy children. The genetic basis of AIS is largely unknown. Systematic genome-wide mutagenesis screens for embryonic phenotypes in zebrafish have been instrumental in the understanding of early patterning of embryonic tissues necessary to build and pattern the embryonic spine. However, the mechanisms required for postembryonic maturation and homeostasis of the spine remain poorly understood. Here we report the results from a small-scale forward genetic screen for adult-viable recessive and dominant mutant zebrafish, displaying overt morphological abnormalities of the adult spine. Germline mutations induced with N-ethyl N-nitrosourea (ENU) were transmitted and screened for dominant phenotypes in 1,229 F1 animals, and subsequently bred to homozygosity in F3 families, from these, 314 haploid genomes were screened for recessive phenotypes. We cumulatively found 39 adult-viable (3 dominant and 36 recessive) mutations each leading to a defect in the morphogenesis of the spine. The largest phenotypic group displayed larval onset axial curvatures, leading to whole-body scoliosis without vertebral dysplasia in adult fish. Pairwise complementation testing within this phenotypic group revealed at least 16 independent mutant loci. Using massively-parallel whole genome or whole exome sequencing and meiotic mapping we defined the molecular identity of several loci for larval onset whole-body scoliosis in zebrafish. We identified a new mutation in the skolios/kinesin family member 6 (kif6) gene, causing neurodevelopmental and ependymal cilia defects in mouse and zebrafish. We also report several recessive alleles of the scospondin and a disintegrin and metalloproteinase with thrombospondin motifs 9 (adamts9) genes, which all display defects in spine morphogenesis. Many of the alleles characterized thus far are non-synonymous mutations in known essential scospondin and adamts9 genes. Our results provide evidence of monogenic traits that are critical for normal spine development in zebrafish, that may help to establish new candidate risk loci for spine disorders in humans.

developmental biology↗

bioRxiv2020

Reduced placental transfer of antibodies against microbial and vaccine antigens in HIV-infected women in Mozambique

Antibody transplacental transfer is essential for conferring protection in newborns against infectious diseases. This transfer may be affected by gestational age and maternal infections, although the effects are not consistent across studies. We measured total IgG and IgG subclasses by quantitative suspension array technology against fourteen pathogens and vaccine antigens, including target of maternal immunization, in 341 delivering HIV- and HIV+ mother-infant pairs from southern Mozambique. Maternal antibody levels were the main determinant of cord antibody levels. HIV broadly reduced the placental transfer and cord levels of IgG and IgG1, but also IgG2 to half of the antigens. Plasmodium falciparum exposure and prematurity were negatively associated with cord antibody levels and placental transfer but this was antigen-subclass dependent. These findings suggest maternal infections may impact the efficacy of maternal immunization and confirm the lower transfer of antibodies as one of the causes underlying increased susceptibility to infections in HIV-exposed infants.

immunology↗

bioRxiv2020

A Method for the Automatic Normalization and 3D Facial Mesh Extraction from Head Magnetic Resonance Imaging

The analysis of 3D facial shape in medicine is motivated by the fact that certain diseases and syndromes are associated to specific facial dysmorphologies. In this context, 3D facial shape analysis constitutes a promising and non-invasive support to traditional diagnostic methods. In this work, we explore the use of head magnetic resonances to obtain accurate 3D facial meshes that enable subsequent facial shape analysis. We present a fully automatic method that normalizes the orientation and alignment of 3D point clouds corresponding to head magnetic resonances by detecting salient facial features. Moreover, using clustering techniques, our method also allows to eliminate noise and artifacts appearing in magnetic resonance imaging. Finally, through bidirectional ray tracing, we obtain a dense 3D facial mesh that accurately captures facial shape. The proposed method has been built and evaluated on a dataset of 185 head magnetic resonances, and it has demonstrated its ability to successfully orient, align and obtain a dense 3D facial mesh with a high accuracy rate.

bioinformatics↗

bioRxiv2020

Revisiting Orthotospovirus Phylogeny Using Whole Genomic Data and a Hypothesis for their Geographic Origin and Diversification

The family Tospoviridae, a member of the Bunyavirales order, is constituted of tri-segmented negative-sense single-stranded RNA viruses that infect plants and are also able of replicating in their insect vectors in a persistent manner. The family is composed of a single genus, the Orthotospovirus, whose type species is Tomato spotted wilt virus (TSWV). Previous studies assessing the phylogenetic relationships within this genus were based upon partial genomic sequences, thus resulting in unresolved clades and a poor assessment of the roles of recombination and genome shuffling during mixed infections. Complete genomic data for most Orthotospovirus species are now available at NCBI genome database. In this study we have used 62 complete genomes from 20 species. Our study confirms the existence of four phylogroups (A to D), grouped in two major clades (A-B and C-D), within the genus. We have estimated the split between the two major clades [~]3,100 years ago shortly followed by the split between the A and B phylogroups [~]2,860 years ago. The split between the C and D phylogroups happened more recently, [~]1,465 years ago. Segment reassortment has been shown to be important in the generation of novel viruses. Likewise, within-segment recombination events have been involved in the origin of new viral species. Finally, phylogeographic analyses of representative viruses suggests the Australasian ecozone as the possible origin of the genus, followed by complex patterns of migration, with rapid global spread and numerous reintroduction events. IMPORTANCEMembers of the Orthotospovirus genus infect a large number of plant families, including food crops and ornamentals, resulting in multimillionaire economical losses. Despite this importance, phylogenetic relationships within the genus were established years ago based in partial genomic sequences. A peculiarity of orthotospoviruses is their tri-segmented negative sense genomes, which makes segment reassortment and within-segment recombination, two forms of viral sex, potential evolutionary forces. Using full genomes from all described orthotospovirus species, we revisited their phylogeny and confirmed the existence of four major phylogroups with uneven geographic distribution. We have also shown a pervasive role of sex in the origin of new viral species. Finally, using Bayesian phylogeographic methods, we assessed the possible geographic origin and historical dispersal of representative viruses from the different phylogroups.

evolutionary biology↗