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In West and Central Africa, as in many regions of the world, vegetables are severely affected by geminivirus diseases. In Burkina Faso, observation of various virus‐like symptoms, especially on tomato, suggests the involvement of several geminiviruses and underlines the pressing need for additional information on their diversity, distribution, prevalence and host plant reservoirs. Large‐scale surveys conducted in Burkina Faso confirmed the presence of tomato (yellow) leaf curl diseases (ToLCD‐TYLCD) and geminiviruses in all localities with mean prevalences of 25% and 45%, respectively. Five geminiviruses including four begomoviruses (pepper yellow vein Mali virus (PepYVMLV), tomato leaf curl Burkina Faso virus, tomato leaf curl Mali virus and tomato leaf curl Ghana virus) and a dicot‐infecting mastrevirus (chickpea chlorotic dwarf virus) were characterized on tomato. In addition, PepYVMLV and cotton leaf curl Gezira virus (CLCuGeV) were characterized on pepper and okra, respectively, in combination or not with alphasatellites and betasatellites for CLCuGeV. The most severe, prevalent and widely distributed virus on vegetables was PepYVMLV, which was characterized for the first time in combination with a genetically divergent DNA‐B component that may constitute a key factor of PepYVMLV pathogenicity. Of the eight weeds identified as potential reservoir hosts of begomoviruses, four host PepYVMLV. The results confirm the importance of geminivirus diseases on vegetable crops in Burkina Faso and highlight the complex association of geminiviruses and satellites. The detection of begomoviruses in weeds growing close to crops points to the increasing necessity to consider reservoir plants and virus communities in the control of virus diseases. [ABSTRACT FROM AUTHOR]

Abstract Background Cassava (Manihot esculenta) is a major food source for over 200 million sub-Saharan Africans. Unfortunately, its cultivation is severely hampered by cassava mosaic disease (CMD). Caused by a complex of bipartite cassava mosaic geminiviruses (CMG) species (Family: Geminivirideae; Genus: Begomovirus) CMD has been widely described throughout Africa and it is apparent that CMG's are expanding their geographical distribution. Determining where and when CMG movements have occurred could help curtail its spread and reveal the ecological and anthropic factors associated with similar viral invasions. We applied Bayesian phylogeographic inference and recombination analyses to available and newly described CMG sequences to reconstruct a plausible history of CMG diversification and migration between Africa and South West Indian Ocean (SWIO) islands. Results The isolation and analysis of 114 DNA-A and 41 DNA-B sequences demonstrated the presence of three CMG species circulating in the Comoros and Seychelles archipelagos (East African cassava mosaic virus, EACMV; East African cassava mosaic Kenya virus, EACMKV; and East African cassava mosaic Cameroon virus, EACMCV). Phylogeographic analyses suggest that CMG’s presence on these SWIO islands is probably the result of at least four independent introduction events from mainland Africa occurring between 1988 and 2009. Amongst the islands of the Comoros archipelago, two major migration pathways were inferred: One from Grande Comore to Mohéli and the second from Mayotte to Anjouan. While only two recombination events characteristic of SWIO islands isolates were identified, numerous re-assortments events were detected between EACMV and EACMKV, which seem to almost freely interchange their genome components. Conclusions Rapid and extensive virus spread within the SWIO islands was demonstrated for three CMG complex species. Strong evolutionary or ecological interaction between CMG species may explain both their propensity to exchange components and the absence of recombination with non-CMG begomoviruses. Our results suggest an important role of anthropic factors in CMGs spread as the principal axes of viral migration correspond with major routes of human movement and commercial trade. Finer-scale temporal analyses of CMGs to precisely scale the relative contributions of human and insect transmission to their movement dynamics will require further extensive sampling in the SWIO region.

Abstract Background Cassava mosaic disease (CMD) is a major constraint on cassava cultivation in Africa. The disease is endemic and is caused by seven distinct cassava mosaic geminiviruses (CMGs), some of them including several variants. Findings From cassava leaf samples presenting CMD symptoms collected in Burkina Faso, four DNA-A begomovirus components were cloned and sequenced, showing 99.9% nucleotide identity among them. These isolates are most closely related to African cassava mosaic virus (ACMV) but share less than 89% nucleotide identity (taxonomic threshold) with any previously described begomovirus. A DNA-B genomic component, sharing 93% nucleotide identity with DNA-B of ACMV, was also characterized. Since all genomic components have a typical genome organization of Old World bipartite begomoviruses, this new species was provisionally named African cassava mosaic Burkina Faso virus (ACMBFV). Recombination analysis of the new virus demonstrated an interspecies recombinant origin, with major parents related to West African isolates of ACMV, and minor parents related to Tomato leaf curl Cameroon virus and Cotton leaf curl Gezira virus. Conclusion This is the first report of an ACMV-like recombinant begomovirus arisen by interspecific recombination between bipartite and monopartite African begomoviruses.

Abstract Background Begomovirus is a genus of phytopathogenic single-stranded DNA viruses, transmitted by the whitefly Bemisia tabaci. This genus includes emerging and economically significant viruses such as those associated with Tomato Yellow Leaf Curl Disease, for which diagnostic tools are needed to prevent dispersion and new introductions. Five real-time PCRs with an internal tomato reporter gene were developed for accurate detection and quantification of monopartite begomoviruses, including two strains of the Tomato yellow leaf curl virus (TYLCV; Mld and IL strains), the Tomato leaf curl Comoros virus-like viruses (ToLCKMV-like viruses) and the two molecules of the bipartite Potato yellow mosaic virus. These diagnostic tools have a unique standard quantification, comprising the targeted viral and internal report amplicons. These duplex real-time PCRs were applied to artificially inoculated plants to monitor and compare their viral development. Results Real-time PCRs were optimized for accurate detection and quantification over a range of 2 × 109 to 2 × 103 copies of genomic viral DNA/μL for TYLCV-Mld, TYLCV-IL and PYMV-B and 2 × 108 to 2 × 103 copies of genomic viral DNA/μL for PYMV-A and ToLCKMV-like viruses. These real-time PCRs were applied to artificially inoculated plants and viral loads were compared at 10, 20 and 30 days post-inoculation. Different patterns of viral accumulation were observed between the bipartite and the monopartite begomoviruses. Interestingly, PYMV accumulated more viral DNA at each date for both genomic components compared to all the monopartite viruses. Also, PYMV reached its highest viral load at 10 dpi contrary to the other viruses (20 dpi). The accumulation kinetics of the two strains of emergent TYLCV differed from the ToLCKMV-like viruses in the higher quantities of viral DNA produced in the early phase of the infection and in the shorter time to reach this peak viral load. Conclusions To detect and quantify a wide range of begomoviruses, five duplex real-time PCRs were developed in association with a novel strategy for the quantification standard. These assays should be of a great interest for breeding programs and epidemiological surveys to monitor viral populations.

Abstract Okra leaf curl disease (OLCD) is a major constraint on okra (Abelmoschus esculentus) production and is widespread in Africa. Using a large number of samples representative of the major growing regions in Burkina Faso (BF), we show that the disease is associated with a monopartite begomovirus and satellite DNA complexes. Twenty-three complete genomic sequences of Cotton leaf curl Gezira virus (CLCuGV) isolates associated with OLCD, sharing 95 to 99% nucleotide identity, were cloned and sequenced. Six betasatellite and four alphasatellite (DNA-1) molecules were also characterized. The six isolates of betasatellite associated with CLCuGV isolates correspond to Cotton leaf curl Gezira betasatellite (CLCuGB) (88 to 98% nucleotide identity). One isolate of alphasatellite is a variant of Cotton leaf curl Gezira alphasatellite (CLCuGA) (89% nucleotide identity), whereas the three others isolates appear to correspond to a new species of alphasatellite (CLCuGA most similar sequence present 52 to 60% nucleotide identity), provisionally named Okra leaf curl Burkina Faso alphasatellite (OLCBFA). Recombination analysis of the viruses demonstrated the interspecies recombinant origin of all CLCuGV isolates, with parents being close to Hollyhock leaf crumple virus (AY036009) and Tomato leaf curl Diana virus (AM701765). Combined with the presence of satellites DNA, these results highlight the complexity of begomoviruses associated with OLCD.

This is the first description of the complete genome sequence of a newly characterized monopartite begomovirus isolated from an asymptomatic uncultivated plant, Melochia tomentosa, collected in Burkina Faso. The sequence was obtained through rolling-circle amplification, cloning, and Sanger sequencing. The provisional species name "Begomovirus melochiae" and common virus name "melochia associated virus" (MeAV) are proposed. The MeAV genome was found to share the most nucleotide sequence similarity with three African monopartite begomoviruses: tomato curly stunt virus (74%), pepper yellow vein Mali virus (73%), and tomato leaf curl Cameroon virus (73%). Phylogenetic analysis confirmed its relationship to Old World monopartite begomoviruses. The discovery of MeAV in an uncultivated and asymptomatic plant provides a further example of the high diversity of begomoviruses in sub-Saharan African ecosystems., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

The establishment of effective antiviral responses within host cells is intricately related to their metabolic status, shedding light on immunometabolism. In this study, we investigated the hypothesis that cellular reliance on glutamine metabolism contributes to the development of a potent antiviral response. We evaluated the antiviral response in the presence or absence of L-glutamine in the culture medium, revealing a bivalent response hinging on cellular metabolism. While certain interferon-stimulated genes (ISGs) exhibited higher expression in an oxidative phosphorylation (OXPHOS)-dependent manner, others were surprisingly upregulated in a glycolytic-dependent manner. This metabolic dichotomy was influenced in part by variations in interferon-β (IFN-β) expression. We initially demonstrated that the presence of L-glutamine induced an enhancement of OXPHOS in A549 cells. Furthermore, in cells either stimulated by poly:IC or infected with dengue virus and Zika virus, a marked increase in ISGs expression was observed in a dose-dependent manner with L-glutamine supplementation. Interestingly, our findings unveiled a metabolic dependency in the expression of specific ISGs. In particular, genes such as ISG54, ISG12 and ISG15 exhibited heightened expression in cells cultured with L-glutamine, corresponding to higher OXPHOS rates and IFN-β signaling. Conversely, the expression of viperin and 2'-5'-oligoadenylate synthetase 1 was inversely related to L-glutamine concentration, suggesting a glycolysis-dependent regulation, confirmed by inhibition experiments. This study highlights the intricate interplay between cellular metabolism, especially glutaminergic and glycolytic, and the establishment of the canonical antiviral response characterized by the expression of antiviral effectors, potentially paving the way for novel strategies to modulate antiviral responses through metabolic interventions.

Background: A series of incurable cardiovascular disorders arise due to improper formation of elastin during development. Supravalvular aortic stenosis (SVAS), resulting from a haploinsufficiency of ELN , is caused by improper stress sensing by medial vascular smooth muscle cells, leading to progressive luminal occlusion and heart failure. SVAS remains incurable, as current therapies do not address the root issue of defective elastin., Methods: We use SVAS here as a model of vascular proliferative disease using both human induced pluripotent stem cell-derived vascular smooth muscle cells and developmental Eln +/- mouse models to establish de novo elastin assembly as a new therapeutic intervention., Results: We demonstrate mitigation of vascular proliferative abnormalities following de novo extracellular elastin assembly through the addition of the polyphenol epigallocatechin gallate to SVAS human induced pluripotent stem cell-derived vascular smooth muscle cells and in utero to Eln +/- mice., Conclusions: We demonstrate de novo elastin deposition normalizes SVAS human induced pluripotent stem cell-derived vascular smooth muscle cell hyperproliferation and rescues hypertension and aortic mechanics in Eln +/- mice, providing critical preclinical findings for the future application of epigallocatechin gallate treatment in humans., Competing Interests: Disclosures M.W. Ellis, J. Luo, and Y. Qyang have filed a patent related to the usage of the polyphenol compound epigallocatechin gallate in the formation of extracellular elastic fibers for the purposes of tissue engineering. The other authors report no conflicts.

Alterations in cell cycle regulation contribute to Zika virus (ZIKV)-associated pathogenesis and may have implications for the development of therapeutic avenues. As a matter of fact, ZIKV alters cell cycle progression at multiple stages, including G1, S, G2, and M phases. During a cell cycle, the progression of mitosis is particularly controlled to avoid any abnormalities in cell division. In this regard, the critical metaphase-anaphase transition is triggered by the activation of anaphase-promoting complex/cyclosome (APC/C) by its E3 ubiquitin ligase subunit Cdc20. Cdc20 recognizes substrates by interacting with a destruction box motif (D-box). Recently, the ZIKV nonstructural protein 5 (NS5), one of the most highly conserved flavivirus proteins, has been shown to localize to the centrosome in each pole and to spindle fibers during mitosis. Inducible expression of NS5 reveals an interaction of this viral factor with centrosomal proteins leading to an increase in the time required to complete mitosis. By analyzing the NS5 sequence, we discovered the presence of a D-box. Taken together, these data support the idea that, in addition to its role in viral replication, NS5 plays a critical role in the control of the cell cycle of infected cells and, more specifically, in the regulation of the mitotic spindle. Here we propose that the NS5 protein may interfere with the metaphase-anaphase progression, and thus cause the observed delay in mitosis via the regulation of APC/C., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.)

DREAM complexes are transcriptional regulators that control the expression of hundreds to thousands of target genes involved in the cell cycle, quiescence, differentiation, and apoptosis. These complexes contain many subunits that can vary according to the considered target genes. Depending on their composition and the nature of the partners they recruit, DREAM complexes control gene expression through diverse mechanisms, including chromatin remodeling, transcription cofactor and factor recruitment at various genomic binding sites. This complexity is particularly high in mammals. Since the discovery of the first dREAM complex (drosophila Rb, E2F, and Myb) in Drosophila melanogaster, model organisms such as Caenorhabditis elegans, and plants allowed a deeper understanding of the processes regulated by DREAM-like complexes. Here, we review the conservation of these complexes. We discuss the contribution of model organisms to the study of DREAM-mediated transcriptional regulatory mechanisms and their relevance in characterizing novel activities of DREAM complexes., (© 2023 The Authors. BioEssays published by Wiley Periodicals LLC.)

The complex architecture of DNA within living organisms is essential for maintaining the genetic information that dictates their functions and characteristics. Among the many complexities of genetic material organization, the folding and arrangement of DNA into chromosomes play a critical role in regulating gene expression, replication, and other essential cellular processes. Bacteria, despite their apparently simple cellular structure, exhibit a remarkable level of chromosomal organization that influences their adaptability and survival in diverse environments. Understanding the three-dimensional arrangement of bacterial chromosomes has long been a challenge due to technical limitations, but the development of Chromosome Conformation Capture (3C) methods revolutionized our ability to explore the hierarchical structure and the dynamics of bacterial genomes. Here, we review the major advances in the field of bacterial chromosome structure using 3C technology over the past decade., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

In recent years, the emergence of the concept of immunometabolism has shed light on the pivotal role that cellular metabolism plays in both the activation of immune cells and the development of immune programs. The antiviral response, a widely distributed defense mechanism used by infected cells, serves to not only control infections but also to attenuate their deleterious effects. The exploration of the role of metabolism in orchestrating the antiviral response represents a burgeoning area of research, especially considering the escalating incidence of viral outbreaks coupled with the increasing prevalence of metabolic diseases. Here, we present a review of current knowledge regarding immunometabolism and the antiviral response during viral infections. Initially, we delve into the concept of immunometabolism by examining its application in the field of cancer-a domain that has long spearheaded inquiries into this fascinating intersection of disciplines. Subsequently, we explore examples of immune cells whose activation is intricately regulated by metabolic processes. Progressing with a systematic and cellular approach, our aim is to unravel the potential role of metabolism in antiviral defense, placing significant emphasis on the innate and canonical interferon response.

Bioelectrochemical systems which employ microbes as electrode catalysts to convert chemical energy into electrical energy (or conversely), have emerged in recent years for water sanitation and energy recovery. Microbial biocathodes, and especially those reducing nitrate are gaining more and more attention. The nitrate-reducing biocathodes can efficiently treat nitrate-polluted wastewater. However, they require specific conditions and they have not yet been applied on a large scale. In this review, the current knowledge on nitrate-reducing biocathodes will be summarized. The fundamentals of microbial biocathodes will be discussed, as well as the progress towards applications for nitrate reduction in the context of water treatment. Nitrate-reducing biocathodes will be compared with other nitrate-removal techniques and the challenges and opportunities of this approach will be identified., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

As highly pervasive parasites that sometimes cause disease, viruses are likely major components of all natural ecosystems. An important step towards both understanding the precise ecological roles of viruses and determining how natural communities of viral species are assembled and evolve is obtaining full descriptions of viral diversity and distributions at ecosystem scales. Here, we focused on obtaining such 'community-scale' data for viruses in a single genus. We chose the genus Mastrevirus (family Geminiviridae), members of which have predominantly been found infecting uncultivated grasses (family Poaceae) throughout the tropical and sub-tropical regions of the world. We sampled over 3 years, 2,884 individual Poaceae plants belonging to thirty different species within a 2-ha plot which included cultivated and uncultivated areas on the island of Reunion. Mastreviruses were found in ∼8 per cent of the samples, of which 96 per cent did not have any discernible disease symptoms. The multitude of host-virus associations that we uncovered reveals both the plant species that most commonly host mastreviruses and the mastrevirus species (such as maize streak virus and maize streak Reunion virus ) that have especially large host ranges. Our findings are consistent with the hypothesis that perennial plant species capable of hosting years-long mixed mastrevirus infections likely play a disproportionately important role in the generation of inter-species and inter-strain mastrevirus recombinants., Competing Interests: In the interests of transparency and to help readers to form their own judgements of potential bias, the authors declare no competing interests in relation to the work described., (© The Author(s) 2023. Published by Oxford University Press.)

Elastic fibers are extracellular macromolecules that provide resilience and elastic recoil to elastic tissues and organs in vertebrates. They are composed of an elastin core surrounded by a mantle of fibrillin-rich microfibrils and are essentially produced during a relatively short period around birth in mammals. Thus, elastic fibers have to resist many physical, chemical, and enzymatic constraints occurring throughout their lives, and their high stability can be attributed to the elastin protein. Various pathologies, called elastinopathies, are linked to an elastin deficiency, such as non-syndromic supravalvular aortic stenosis (SVAS), Williams-Beuren syndrome (WBS), and autosomal dominant cutis laxa (ADCL). To understand these diseases, as well as the aging process related to elastic fiber degradation, and to test potential therapeutic molecules in order to compensate for elastin impairments, different animal models have been proposed. Considering the many advantages of using zebrafish, we here characterize a zebrafish mutant for the elastin a paralog ( elna sa12235 ) with a specific focus on the cardiovascular system and highlight premature heart valve defects at the adult stage.

Background: Proven toxicity and environmental burdens caused by artificial dyes have motivated dyeing industries to turn to natural alternatives. Plant-based dyestuffs are an interesting group of alternative crops. Reunion Island located in the Indian Ocean is the only European region in the southern hemisphere. It has a great number of assets to find new molecules in the abundant plant biodiversity. However, the dye-producing plants diversity in this island had not been documented to date., Methodology: The assessment of the Reunion Island's plant biodiversity through the "PLANTIN" project allowed us to establish here the first ethnobotanical inventory of plants growing on Reunion Island which may have promising properties as a new alternative source of dyes or colorants for the industries. First, an ethnobotanical survey focused on the uses of plants traditionally used in dyeing was conducted on local stakeholders. Then, the importance of different criteria (e.g., endemicity, accessibility and cultivability, plant organs used for the extraction, industrial interests of the species, etc.) has been considered to establish a classification method of the species, to finally select the most interesting plants which have been further harvested and investigated for their coloring property and dyeing application on natural fibers., Results: The results showed that local people have accumulated traditional knowledge of dyeing plants, but that this approach had been discontinued in Reunion. The uses of 194 plant species potentially rich in dyes or pigments, belonging to 72 different families, with diverse botanical status (endemic, native, introduced or alien-invasive species) have been recorded. Then, 43 species were harvested and their coloring property were investigated. It demonstrated that dyes extracted from promising species, e.g., Terminalia bentzoe, Weinmannia tinctoria, Thespesia populnea, Erythroxylum laurifolium, Morinda citrifolia, Leea guinensis, Ochrosia borbonica, Danais fragrans, Terminalia cattapa, Casuarina equisetifolia, and Coccoloba uvifera, amongst others, could be used as new textile dyes. Their efficacy in the wool and cotton dyeing has been successfully demonstrated here., Conclusion: These plant-based dyestuffs showed promising coloring properties with different shades that could meet industrial application requirement. It's an area that could promote local cultural inheritance, create opportunity for business and farmers, and that can make a significant contribution to preserving endangered native species by supporting reforestation schemes. Additional researches are in progress to evaluate the safety of these plant-based colored extracts, their chemical composition and biological activities., (© 2023. The Author(s).)

Extracellular vesicles (EVs), produced during viral infections, are of emerging interest in understanding infectious processes and host-pathogen interactions. EVs and exosomes in particular have the natural ability to transport nucleic acids, proteins, and other components of cellular or viral origin. Thus, they participate in intercellular communication, immune responses, and infectious and pathophysiological processes. Some viruses are known to hijack the cell production and content of EVs for their benefit. Here, we investigate whether two pathogenic flaviviruses i.e., Zika Virus (ZIKV) and Dengue virus (DENV2) could have an impact on the features of EVs. The analysis of EVs produced by infected cells allowed us to identify that the non-structural protein 1 (NS1), described as a viral toxin, is associated with exosomes. This observation could be confirmed under conditions of overexpression of recombinant NS1 from each flavivirus. Using different isolation methods (i.e., exosome isolation kit, size exclusion chromatography, Polyethylene Glycol enrichment, and ELISA capture), we showed that NS1 was present as a dimer at the surface of excreted exosomes, and that this association could occur in the extracellular compartment. This finding could be of major importance in a physiological context. Indeed, this capacity of NS1 to address EVs and its implication in the pathophysiology during Dengue or Zika diseases should be explored. Furthermore, exosomes that have demonstrated a natural capacity to vectorize NS1 could serve as useful tools for vaccine development.

When exposed to a viral infection, the attacked cells promptly set up defense mechanisms. As part of the antiviral responses, the innate immune interferon pathway and associated interferon-stimulated genes notably allow the production of proteins bearing antiviral activity. Numerous viruses are able to evade the interferon response, highlighting the importance of controlling this pathway to ensure their efficient replication. Several viruses are also known to manipulate the metabolism of infected cells to optimize the availability of amino acids, nucleotides, and lipids. They then benefit from a reprogramming of the metabolism that favors glycolysis instead of mitochondrial respiration. Given the increasingly discussed crosstalk between metabolism and innate immunity, we wondered whether this switch from glycolysis to mitochondrial respiration would be beneficial or deleterious for an efficient antiviral response. We used a cell-based model of metabolic reprogramming. Interestingly, we showed that increased mitochondrial respiration was associated with an enhanced interferon response following polyriboinosinic:polyribocytidylic acid (poly:IC) stimulation. This suggests that during viral infection, the metabolic reprogramming towards glycolysis is also part of the virus' strategies to inhibit the antiviral response.

Drosophila melanogaster imaginal discs are larval internal structures that become the external organs of the adult. They have been used to study numerous developmental processes for more than fifty years. Dissecting these imaginal discs for collection is challenging, as the size of third-instar larvae organs is typically less than 1 mm. Certain experimental applications of the organs require many cells, which requires researchers to spend several hours dissecting them. This paper proposes an alternative to dissection in the form of a mass enrichment protocol. The protocol enables the recovery of many wing imaginal discs by grinding large quantities of third-instar larvae and separating the organs using filtration and a density gradient. The wing imaginal discs collected with this protocol in less than three hours are as well preserved as those collected by dissection. The dissociation and filtration of the extract allow the isolation of a large amount of wing imaginal disc cells.

Many extensible tissues such as skin, lungs, and blood vessels require elasticity to function properly. The recoil of elastic energy stored during a stretching phase is provided by elastic fibers, which are mostly composed of elastin and fibrillin-rich microfibrils. In arteries, the lack of elastic fibers leads to a weakening of the vessel wall with an increased risk to develop cardiovascular defects such as stenosis, aneurysms, and dissections. The development of new therapeutic molecules involves preliminary tests in animal models that recapitulate the disease and whose response to drugs should be as close as possible to that of humans. Due to its superior in vivo imaging possibilities and the broad tool kit for forward and reverse genetics, the zebrafish has become an important model organism to study human pathologies. Moreover, it is particularly adapted to large scale studies, making it an attractive model in particular for the first steps of investigations. In this review, we discuss the relevance of the zebrafish model for the study of elastic fiber-related vascular pathologies. We evidence zebrafish as a compelling alternative to conventional mouse models.

In recent decades, a legion of monopartite begomoviruses transmitted by the whitefly Bemisia tabaci has emerged as serious threats to vegetable crops in Africa. Recent studies in Burkina Faso (West Africa) reported the predominance of pepper yellow vein Mali virus (PepYVMLV) and its frequent association with a previously unknown DNA-B component. To understand the role of this DNA-B component in the emergence of PepYVMLV, we assessed biological traits related to virulence, virus accumulation, location in the tissue and transmission. We demonstrate that the DNA-B component is not required for systemic movement and symptom development of PepYVMLV (non-strict association), but that its association produces more severe symptoms including growth arrest and plant death. The increased virulence is associated with a higher viral DNA accumulation in plant tissues, an increase in the number of contaminated nuclei of the phloem parenchyma and in the transmission rate by B. tabaci. Our results suggest that the association of a DNA-B component with the otherwise monopartite PepYVMLV is a key factor of its emergence., (© 2022. The Author(s).)

Apoptosis is associated with numerous phenotypical characteristics, and is thus studied with many tools. In this study, we compared two broadly used apoptotic assays: TUNEL and staining with an antibody targeting the activated form of an effector caspase. To compare them, we developed a protocol based on commonly used tools such as image filtering, z-projection, and thresholding. Even though it is commonly used in image-processing protocols, thresholding remains a recurring problem. Here, we analyzed the impact of processing parameters and readout choice on the accuracy of apoptotic signal quantification. Our results show that TUNEL is quite robust, even if image processing parameters may not always allow to detect subtle differences of the apoptotic rate. On the contrary, images from anti-cleaved caspase staining are more sensitive to handle and necessitate being processed more carefully. We then developed an open-source Fiji macro automatizing most steps of the image processing and quantification protocol. It is noteworthy that the field of application of this macro is wider than apoptosis and it can be used to treat and quantify other kind of images.

In this report, we present the first description of the complete genome sequences of a new monopartite begomovirus isolated from tomato with symptoms of interveinal yellowing of leaves collected in the region of Worodougou in the northwest of Côte d'Ivoire and provisionally named "tomato interveinal yellowing virus" (ToIYV). The DNA-A-like nucleotide sequences of ToIYV share the highest nucleotide sequence identity (83%) with tobacco leaf curl Zimbabwe virus (ToLCZWV). Phylogenetic analysis confirmed that ToIYV is related to Old World monopartite begomoviruses. The discovery of a member of a new virus species on diseased tomato plants confirms the high genetic diversity in monopartite begomoviruses in West Africa and stresses the importance of maintaining epidemiological crop surveillance.

Next-generation sequencing (NGS), through the implementation of metagenomic protocols, has led to the discovery of thousands of new viruses in the last decade. Nevertheless, these protocols are still laborious and costly to implement, and the technique has not yet become routine for everyday virus characterization. Within the context of CRESS DNA virus studies, we implemented two alternative long-read NGS protocols, one that is agnostic to the sequence (without a priori knowledge of the viral genome) and the other that use specific primers to target a virus (with a priori). Agnostic and specific long read NGS-based assembled genomes of two capulavirus strains were compared to those obtained using the gold standard technique of Sanger sequencing. Both protocols allowed the detection and accurate full genome characterization of both strains. Globally, the assembled genomes were very similar (99.5-99.7% identity) to the Sanger sequences consensus, but differences in the homopolymeric tracks of these sequences indicated a specific lack of accuracy of the long reads NGS approach that has yet to be improved. Nevertheless, the use of the bench-top sequencer has proven to be a credible alternative in the context of CRESS DNA virus study and could offer a new range of applications not previously accessible.

Microbial electrodes were designed in domestic wastewaters to catalyse the oxidation of organic matter (anode) and the reduction of oxygen (cathode) alternately. The successive aeration phases (cathode) enhanced the anodic efficiency, resulting in current densities of up to 6.4 Am -2 without the addition of any substrate. Using nitrogen during the anodic phases affected the microbial populations and the electrodes showed a lower ability to subsequently turn to O 2 reduction than the microbial anodes formed in open-to-air conditions did. No strong difference was observed between internal and external biofilm, both of which showed a very large variety of taxa in terms of abundance as well as variance. They comprised a mix of aerobic and anaerobic species, many of which have already been identified separately in bioelectrochemical systems. Such a large diversity, which had not been observed in aerobic bidirectional bioelectrodes so far, can explain the efficiency and robustness observed here., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This is the first description of the complete genome sequence of a new monopartite begomovirus isolated from tomato with symptoms of tomato (yellow) leaf curl disease collected in northwestern Namibia, which we provisionally name "tomato leaf curl Kunene virus". The DNA-A-like nucleotide sequence shares the highest nucleotide sequence identity (82.8%) with tobacco leaf curl Zimbabwe virus (ToLCZWV). Phylogenetic analysis confirmed its affiliation with Old World monopartite begomoviruses. The discovery of a new begomovirus in a vegetable plant in Namibia highlights the importance of maintaining epidemiological surveillance in southern Africa.

Nine complete nucleotide sequences of geminialphasatellites (subfamily Geminialphasatellitinae, family Alphasatellitidae) recovered from the wild Poaceae Sorghum arundinaceum collected in Reunion are described and analyzed. While the helper geminivirus was identified as an isolate of maize streak virus (genus Mastrevirus, family Geminiviridae), the geminialphasatellite genomes were most closely related to, and shared ~63% identity with, clecrusatellites. Even though the geminialphasatellite molecules lack an adenine rich-region, they have the typical size of geminialphasatellites, encode a replication-associated protein in the virion sense, and have probable stem-loop structures at their virion-strand origins of replication. According to the proposed geminialphasatellite species and genus demarcation thresholds (88% and 70% nucleotide identity, respectively), the genomes identified here represent a new species (within a new genus) for which we propose the name "Sorghum mastrevirus-associated alphasatellite" (genus "Sorgasalphasatellite").