Genomas de geminivirus: pequeños pero matones

All living organisms possess a genome, constituted by nucleic acid, which encodes the proteins necessary to complete their life cycle and interact with the environment. Without entering into the more or less philosophical disquisition of whether viruses are living organisms or not, what can be affirmed is that life on Earth cannot be imagined without the existence of these “simple” organisms. Viruses possess a genome of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) that is usually encapsulated in a more or less complex protein cover that sometimes contains lipid components. The size of the viral genome varies enormously between species.Todos los organismos vivos poseen un genoma, constituido por ácido nucleico, que codifica las proteínas necesarias para comple- tar su ciclo vital e interaccionar con el medio ambiente. Sin entrar en la disquisición más o menos filosófica de si los virus son o no organismos vivos, lo que sí puede afirmarse es que la vida en la Tierra no puede imaginarse sin la existencia de estos "sencillos" organismos. Los virus poseen un genoma de ácido desoxirribo- nucleico (ADN) o ácido ribonucleico (ARN) que suele encapsidarse en  una  cubierta  proteica más o menos compleja que en ocasiones con- tiene componentes lipídicos. El tamaño del genoma viral varía enormemente entre especies

¿PUEDEN LOS VIRUS DE PLANTAS SER PATOGÉNICOS EN HUMANOS?

[EN] Virus infections in plants are very frequent, including those affecting crops of major economic importance. Plant viruses are present in many foods that are part of our daily diet, especially in fruits and vegetables. Although there are some studies suggesting that barriers between plants and mammals could be surpassed by some viruses, there is no evidence that plant viruses are causative agents of any disease in humans or other mammals.[ES] Las infecciones de virus en plantas son muy frecuentes, incluyendo las que afectan a cultivos de gran impor tancia económica. Los virus de plantas están presentes en muchos alimentos que forman par te de nuestra dieta diaria, especialmente en frutas y verduras. Aunque existen algunos trabajos que sugieren que las barreras entre plantas y mamíferos podrían ser sobrepasadas por algunos virus, no existen evidencias de que los virus de plantas sean agentes causales de ninguna enfermedad en humanos u otros mamíferos.Fiallo-Olivé, E.; Pallás Benet, V.; Navas-Castillo, J. (2017). ¿PUEDEN LOS VIRUS DE PLANTAS SER PATOGÉNICOS EN HUMANOS?. Virología. 20(2):60-63. http://hdl.handle.net/10251/102628S606320

Sweepoviruses Cause Disease in Sweet Potato and Related Ipomoea spp.: Fulfilling Koch's Postulates for a Divergent Group in the Genus Begomovirus

Sweet potato (Ipomoea batatas) and related Ipomoea species are frequently infected by monopartite begomoviruses (genus Begomovirus, family Geminiviridae), known as sweepoviruses. Unlike other geminiviruses, the genomes of sweepoviruses have been recalcitrant to rendering infectious clones to date. Thus, Koch's postulates have not been fullfilled for any of the viruses in this group. Three novel species of sweepoviruses have recently been described in Spain: Sweet potato leaf curl Lanzarote virus (SPLCLaV), Sweet potato leaf curl Spain virus (SPLCSV) and Sweet potato leaf curl Canary virus (SPLCCaV). Here we describe the generation of the first infectious clone of an isolate (ES:MAL:BG30:06) of SPLCLaV. The clone consisted of a complete tandem dimeric viral genome in a binary vector. Successful infection by agroinoculation of several species of Ipomoea (including sweet potato) and Nicotiana benthamiana was confirmed by PCR, dot blot and Southern blot hybridization. Symptoms observed in infected plants consisted of leaf curl, yellowing, growth reduction and vein yellowing. Two varieties of sweet potato, ‘Beauregard’ and ‘Promesa’, were infected by agroinoculation, and symptoms of leaf curl and interveinal loss of purple colouration were observed, respectively. The virus present in agroinfected plants was readily transmitted by the whitefly Bemisia tabaci to I. setosa plants. The progeny virus population present in agroinfected I. setosa and sweet potato plants was isolated and identity to the original isolate was confirmed by sequencing. Therefore, Koch's postulates were fulfilled for the first time for a sweepovirus

iNGS: a prototype tool for genome interpretation and annotation

Currently, clinical interpretation of whole-genome NGS genetic findings are very low-throughput because of a lack of computational tools/software. The current bottleneck of whole-genome and whole-exome sequencing projects is in structured data management and sophisticated computational analysis of experimental data. In this work, we have started designing a platform for integrating, in a first step, existing analysis tools and adding annotations from public databases to the findings of these tools. This platform can be used to produce tools for different kind of users. As a first experiment with this platform, we have developed a Web tools for running multiple analysis tasks, completing the findings with public data and producing a simple report similar to blood test reports.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. The Project Grant (TIN2011-25840) (Spanish Ministry of Education and Science) and P11-TIC-7529 (Innovation, Science and Enterprise Ministry of the regional government of the Junta de Andalucía)

Only the B biotype of Bemisia tabaci is present on vegetables in São Paulo State, Brazil

Bemisia tabaci (Genn.) is one of the most important pests in cultivated areas of vegetables and ornamental crops around the world. Based on the mitochondrial cytochrome oxidize I (mtCOI) sequence, there is evidence that B. tabaci should be considered a cryptic species complex of 11 groups containing 24 species. Two of the groups, Middle East-Asia Minor 1 and Mediterranean include biotypes B and Q, respectively. In this study we evaluated the mtCOI sequence of B. tabaci populations collected in sites of the state of São Paulo, Brazil. Using PCR-RFLP with Taq I, a typical biotype B profile was obtained for all specimens. Based on the comparison with mtCOI reference sequences we found four haplotypes all belonging to the Middle East-Asia Minor 1. They occurred in the hosts pepper (Capsicum annuum L.), tomato (Solanum lycopersicum L.), eggplant (Solanum melongena L.) and cucurbitaceae plants.Bemisia tabaci (Genn.) é considerada uma das mais importantes pragas em cultivos de hortaliças e ornamentais em todo o mundo. Baseado na análise da seqüência mitocondrial (citocromo oxidase I - mtCOI) foi proposto recentemente que B. tabaci deva ser considerado um complexo críptico de espécies, contendo 11 grupos e 24 espécies. Dois destes grupos: Middle East-Asia Minor e Mediterranean englobam os biótipos B e Q, respectivamente. Avaliou-se a sequência mtCOI de espécimes de B. tabaci coletados em regiões do estado de São Paulo, Brasil. Por PCR-RFLP utilizando-se a enzima Taq I, pôde-se observar somente o padrão típico de clivagem para o biótipo B. Comparando-se com sequências consenso, todas as moscas brancas foram classificadas no grupo Middle East-Asia Minor e puderam ser separadas em quatro haplótipos, indicando prevalência do biótipo B em áreas de pimentão (Capsicum annuum L.), tomate (Solanum lycopersicum L.), cucurbitáceas e berinjela (Solanum melongena L.) do Estado de São Paulo

A novel East African monopartite begomovirus-betasatellite complex that infects Vernonia amygdalina

The complete genomes of a monopartite begomovirus (genus Begomovirus, family Geminiviridae) and an associated betasatellite found infecting Vernonia amygdalina Delile (family Compositae) in Uganda were cloned and sequenced. Begomoviruses isolated from two samples showed the highest nucleotide sequence identity (73.1% and 73.2%) to an isolate of the monopartite begomovirus tomato leaf curl Vietnam virus, and betasatellites from the same samples exhibited the highest nucleotide sequence identity (67.1% and 68.2%) to vernonia yellow vein Fujian betasatellite. Following the current taxonomic criteria for begomovirus species demarcation, the isolates sequenced here represent a novel begomovirus species. Based on symptoms observed in the field, we propose the name vernonia crinkle virus (VeCrV) for this novel begomovirus and vernonia crinkle betasatellite (VeCrB) for the associated betasatellite. This is the first report of a monopartite begomovirus-betasatellite complex from Uganda

Molecular characterization reveals Brazilian Tomato chlorosis virus to be closely related to a Greek isolate

Tomato chlorosis virus (ToCV, genus Crinivirus, family Closteroviridae) is a whitefly-transmitted crinivirus with a bipartite RNA genome. This virus is emerging as a serious threat to tomato crops worldwide. To date, only three complete genomic sequences of ToCV have been described from North America, Spain, and Greece isolates. In this study, we present the fourth complete nucleotide sequence of the RNA 1 (8594 nt) and RNA 2 (8242 nt) components of a Brazilian ToCV isolate (ToCV-BR). The complete genome sequences of RNA 1 and RNA 2 have been deposited in the GenBank database under the accession numbers JQ952600 and JQ952601, respectively. The sequences of RNA 1 and RNA 2 shares the highest nucleotide identity of 99.6% and 99.5%, respectively, with the Greek isolate sequences. Phylogenetic analysis confirmed that both RNA 1 and RNA 2 of the Brazilian isolate are most closely related to the Greek isolate of that virus. These results suggest that ToCV may have been recently introduced to Brazil from Europe

Evolutionary origins of metabolic reprogramming in cancer

Metabolic changes that facilitate tumor growth are one of the hallmarks of cancer. These changes are not specific to tumors but also take place during the physiological growth of tissues. Indeed, the cellular and tissue mechanisms present in the tumor have their physiological counterpart in the repair of tissue lesions and wound healing. These molecular mechanisms have been acquired during metazoan evolution, first to eliminate the infection of the tissue injury, then to enter an effective regenerative phase. Cancer itself could be considered a phenomenon of antagonistic pleiotropy of the genes involved in effective tissue repair. Cancer and tissue repair are complex traits that share many intermediate phenotypes at the molecular, cellular, and tissue levels, and all of these are integrated within a Systems Biology structure. Complex traits are influenced by a multitude of common genes, each with a weak effect. This polygenic component of complex traits is mainly unknown and so makes up part of the missing heritability. Here, we try to integrate these different perspectives from the point of view of the metabolic changes observed in cancer.This work was supported in JPL’s lab by Grant PID2020-118527RB-I00 funded by MCIN/AEI/10.13039/501100011039; Grant PDC2021-121735-I00 funded by MCIN/AEI/10.13039/501100011039 and by the “European Union Next Generation EU/PRTR.”, the Regional Government of Castile and León (CSI234P18 and CSI144P20). SCLl was the recipient of a Ramón y Cajal research contract from the Spanish Ministry of Economy and Competitiveness and was supported by grant RTI2018-094130-B-100 funded by MCIN/AEI/10.13039/501100011039 and by “ERDF A way of making Europe.” RCC and AJN are funded by fellowships from the Spanish Regional Government of Castile and León. NGS is a recipient of an FPU fellowship (MINECO/FEDER). MJPB is funded by grant PID2020-118527RB-I00 funded by MCIN/AEI/10.13039/501100011039. J.C. is partially supported by grant GRS2139/A/20 (Gerencia Regional de Salud de Castilla y León) and by the Instituto de Salud Carlos III (PI18/00587 and PI21/01207), co-financed by FEDER funds, and by the “Programa de Intensificación” of the ISCIII, grant number INT20/00074. We thank Phil Mason for English language support

Differential Shape of Geminivirus Mutant Spectra Across Cultivated and Wild Hosts With Invariant Viral Consensus Sequences

Geminiviruses (family Geminiviridae) possess single-stranded circular DNA genomes that are replicated by cellular polymerases in plant host cell nuclei. In their hosts, geminivirus populations behave as ensembles of mutant and recombinant genomes, known as viral quasispecies. This favors the emergence of new geminiviruses with altered host range, facilitating new or more severe diseases or overcoming resistance traits. In warm and temperate areas several whitefly-transmitted geminiviruses of the genus Begomovirus cause the tomato yellow leaf curl disease (TYLCD) with significant economic consequences. TYLCD is frequently controlled in commercial tomatoes by using the dominant Ty-1 resistance gene. Over a 45 day period we have studied the diversification of three begomoviruses causing TYLCD: tomato yellow leaf curl virus (TYLCV), tomato yellow leaf curl Sardinia virus (TYLCSV) and tomato yellow leaf curl Malaga virus (TYLCMaV, a natural recombinant between TYLCV and TYLCSV). Viral quasispecies resulting from inoculation of geminivirus infectious clones were examined in plants of susceptible tomato (ty-1/ty-1), heterozygous resistant tomato (Ty-1/ty-1), common bean, and the wild reservoir Solanum nigrum. Differences in virus fitness across hosts were observed while viral consensus sequences remained invariant. However, the complexity and heterogeneity of the quasispecies were high, especially in common bean and the wild host. Interestingly, the presence or absence of the Ty-1 allele in tomato did not lead to differences in begomovirus mutant spectra. However, the fitness decrease of TYLCSV and TYLCV in tomato at 45 dpi might be related to an increase in CP (Coat protein) mutation frequency. In Solanum nigrum the recombinant TYLCMaV, which showed lower fitness than TYLCSV, at 45 dpi actively explored Rep (Replication associated protein) ORF but not the overlapping C4. Our results underline the importance of begomovirus mutant spectra during infections. This is especially relevant in the wild reservoir of the viruses, which has the potential to maintain highly diverse mutant spectra without modifying their consensus sequences

Desmodium mottle virus, the first legumovirus (genus Begomovirus) from East Africa

A novel bipartite legumovirus (genus Begomovirus, family Geminiviridae), that naturally infects the wild leguminous plant Desmodium sp. in Uganda, was molecularly characterized and named Desmodium mottle virus. The highest nucleotide identities for DNA-A, obtained from two field-collected samples, were 79.9% and 80.1% with the legumovirus, soybean mild mottle virus. DNA-B had the highest nucleotide identities (65.4% and 66.4%) with a typical non-legumovirus Old World begomovirus, African cassava mosaic virus. This is the first report of a legumovirus in East Africa and extends the known diversity of begomoviruses found infecting wild plants in this continent