For multihost pathogens, adaptation to multiple hosts has important implications for both applied and basic research. At the level, it is one of main factors determining probability severity emerging disease outbreaks. thought be a key mechanism maintenance genetic diversity in host pathogen species. Using Tobacco etch potyvirus (TEV) four natural hosts, we have designed an evolution experiment whose strength novelty are use complex multicellular organism as high level replication different...

CRISPR-Cas is a form of adaptive sequence-specific immunity in microbes. This system offers unique opportunities for the study coevolution between bacteria and their viral pathogens, bacteriophages. A full understanding coevolutionary dynamics requires knowing magnitude cost resisting infection. Here, using gram-positive bacterium Streptococcus thermophilus its associated virulent phage 2972, well-established model harbouring at least two type II functional systems, we obtained different...

ABSTRACT A biotechnological application of artificial microRNAs (amiRs) is the generation plants that are resistant to virus infection. This resistance has proven be highly effective and sequence specific. However, before these transgenic can deployed in field, it important evaluate likelihood emergence resistance-breaking mutants. Two issues particular interest: (i) whether such mutants arise nontransgenic may act as reservoirs (ii) a suboptimal expression level transgene, resulting...

A multicellular organism is not a monolayer of cells in flask; it complex, spatially structured environment, offering both challenges and opportunities for viruses to thrive. Whereas virus infection dynamics at the host within-cell levels have been documented, intermediate between-cell level remains poorly understood. Here, we used flow cytometry measure status thousands individual virus-infected plants. This approach allowed us determine accurately number infected by two variants same host,...

The importance of historical contingency in determining the potential viral populations to evolve has been largely unappreciated. Identifying constraints imposed by past adaptations is, however, for understanding many questions evolutionary biology, such as evolution host usage dynamics multi-host viruses or emergence escape mutants that persist absence antiviral treatments. To address this issue, we undertook an experimental approach which sixty lineages Tobacco etch potyvirus differ their...

Plant artificial micro-RNAs (amiRs) have been engineered to target viral genomes and induce their degradation. However, the exceptional evolutionary plasticity of RNA viruses threatens durability resistance conferred by these amiRs. It has recently shown that populations not experiencing strong selective pressure from an antiviral amiR may already contain enough genetic variability in sequence escape plant almost deterministic manner. Furthermore, it also exposed subinhibitory concentrations...

ABSTRACT A drawback of recent antiviral therapies based on the transgenic expression artificial microRNAs (amiRs) is ease with which viruses generate escape mutations. Here, we show two alternative strategies for improving effectiveness resistance in plants. First, expressed amiRs complementary to independent targets viral genome, and second, designed highly conserved RNA motifs genome.

Conformational intrinsic disorder is a feature present in many virus proteins. Intrinsically disordered regions (IDRs) have weaker structural requirement than ordered and mutations IDRs could lower impact on the fitness. This favor its exploration of adaptive solutions. The potyviral protein VPg contains with determinants for adaptation to host plant. To experimentally assess whether are more resistant regions, biologically relevant interaction between mutant libraries both eukaryotic...

In the clinic, farm, or field, for many viruses there is a high prevalence of mixed-genotype infections, indicating that multiple virions have initiated infection and can be sites primary within same host. The dynamic process by which interact with each other host poorly understood, undoubtedly due to its complexity. this study, we attempted unravel basic interactions underlying using plant RNA virus, as removing inoculated leaf instantly rigorously eliminate all sites. Effective population...

Understanding the evolution of virulence for RNA viruses is essential developing appropriate control strategies. Although it has been usually assumed that a consequence within-host replication parasite, viral strains may be highly virulent without experiencing large accumulation as immunopathological host responses. Using two Tobacco etch potyvirus (TEV) show negative relationship between and rate, we first explored fitness traits during simple mixed infections. Short-term experiments...

The increasing abundance of sequence data has exacerbated a long known problem: gene trees and species for the same terminal taxa are often incongruent. Indeed, genes within genome have not all followed evolutionary path due to events such as incomplete lineage sorting, horizontal transfer, duplication deletion, or recombination. Considering conflicts between an obstacle, numerous methods been developed deal with these incongruences reconstruct consensus histories despite heterogeneity in...

Intrinsically disordered regions (IDRs) are abundant in the proteome of RNA viruses. The multifunctional properties these widely documented and their structural flexibility is associated with low constraint amino acid positions. Therefore, from an evolutionary stand point, could have a greater propensity to accumulate non-synonymous mutations (NS) than highly structured (ORs, or 'ordered regions'). To address this hypothesis, we compared distribution (NS), which relate here mutational...

A recommendation of: Guillaume Lafforgue, Marie Lefebvre, Thierry Michon, Santiago F. Elena How do plant RNA viruses overcome the negative effect of Muller s ratchet despite strong transmission bottlenecks? https://doi.org/10.1101/2023.08.01.550272

Muller's ratchet refers to the irreversible accumulation of deleterious mutations in small populations, resulting a decline overall fitness. This phenomenon has been extensively observed experiments involving microorganisms, including bacteriophages and yeast. While impact Muller’s on viruses largely studied animal RNA viruses, its effects plant remain poorly documented. Plant give rise large diverse populations that undergo significant bottlenecks during colonization distant tissues or...

ABSTRACT Muller’s ratchet refers to the irreversible accumulation of deleterious mutations in small populations, resulting a decline overall fitness. This phenomenon has been extensively observed experiments involving microorganisms, including bacteriophages and yeast. While impact on viruses largely studied animal RNA viruses, its effects plant remain poorly documented. Plant give rise large diverse populations that undergo significant bottlenecks during colonization distant tissues or...

Abstract Intrinsically disordered regions (IDRs) are abundant in the proteome of RNA viruses. The multifunctional properties these widely documented and their structural flexibility is associated with low constraint amino acid positions. Therefore, from an evolutionary stand point, could have a greater mutational permissiveness than highly structured (ORs for Ordered Regions). They thus provide potential adaptive reservoir. To address this hypothesis, we compared robustness IDRs ORs genome...