836 research outputs found
Quantitative phylogenomic evidence reveals a spatially structured SARS-CoV-2 diversity
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emergent RNA virus that spread around the planet in about 4 months. The consequences of this rapid dispersion are under investigation. In this work, we analyzed thousands of genomes and protein sequences from Africa, America, Asia, Europe, and Oceania. We provide statistically significant evidence that SARS-CoV-2 phylogeny is spatially structured. Remarkably, the virus phylogeographic patterns were correlated with ancestral amino acidic substitutions, suggesting that such mutations emerged along colonization events. We hypothesize that geographic structuring is the result of founder effects occurring as a consequence of, and local evolution occurring after, long-distance dispersion. Based on previous studies, the possibility that this could significantly affect the virus biology is not remote.Fil: Jones, Leandro Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Trelew. Laboratorio de Virología y Genética Molecular; ArgentinaFil: Manrique, Julieta Marina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Trelew. Laboratorio de Virología y Genética Molecular; Argentin
Phylogenetic analysis of Ostreococcus virus sequences from the Patagonian Coast
A phylogenetic analysis of new Ostreococcus virus (OV) sequences from the Patagonian Coast, Argentina, and homologous sequences from public databases was performed. This analysis showed that the Patagonian sequences represented a divergent viral clade and that the rest of OV sequences analyzed here were clustered into six additional phylogenetic groups. Analyses of 18S gene libraries supported a close relationship of the Patagonian Ostreococcus host with clade A sequences described elsewhere, corroborating previous studies indicating that clade A strains are ubiquitous. Besides the Patagonian OV sequences, several phylogenetic groupings were linked to particular geographic locations, suggesting a role for allopatric cladogenesis in viral diversification. However, and in agreement with previous observations, other viral lineages included sequences with diverse geographic origins. These findings, together with analyses of ancestral trait trajectories performed here, are consistent with an evolutionary dynamics in which geographical isolation has a role in OV diversification but can be followed by rapid dispersion to remote places.Fil: Manrique, Julieta Marina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Playa Unión. Estación de Fotobiología Playa Unión; ArgentinaFil: Calvo, Andrea Yamila. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Playa Unión. Estación de Fotobiología Playa Unión; ArgentinaFil: Jones, Leandro Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Playa Unión. Estación de Fotobiología Playa Unión; Argentin
An optimized DNA extraction protocol for benthic Didymosphenia geminata
Didymosphenia geminata mats display few cells in relation to extracellular material and contain polysaccharides and heavy metals that interfere with molecular studies. We describe an optimized DNA extraction protocol that help to overcome these difficulties. Our protocol outperformed five previously described DNA extraction techniques.Fil: Uyua, Noelia Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew; ArgentinaFil: Manrique, Julieta Marina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew; ArgentinaFil: Jones, Leandro Roberto. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew; Argentin
Inter and intra-host variability of hepatitis C virus genotype 1a hypervariable envelope coding domains followed for a 4-11 year of human immunodeficiency virus coinfection and highly active antiretroviral therapy
The evolution of hepatitis C virus (HCV) quasispecies in patients with HIV-1 coinfection is not fully understood. The HCV-1a quasispecies heterogeneity was analyzed at inter and intra-host levels along 7.6 years in 21 coinfected patients that showed different virological and immunological responses to highly active antiretroviral therapy (HAART). Two to nine serial samples were subjected to direct and clonal sequence analyses of the envelope glycoprotein 2 (E2) gene. E2-based phylogenies, intra-host HCV evolution and evolutionary rates, as well as dynamics of the quasispecies heterogeneity parameters were evaluated. Bayesian coalescent phylogenies indicated complex evolutionary histories, revealing some viral lineages that persisted along the follow up and others that were detectable at a single or some sampling times, suggesting the occurrence of emergence-extinction cycles. HCV quasispecies underwent very rapid evolution in HAART-treated patients (~3.1 × 10(-2) sub/site/year) following the recovery of the host immunocompetence irrespectively of the virological response to HAART.Fil: Sede, Mariano Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Jones, Leandro Roberto. Universidad Nacional de la Patagonia ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Moretti, Franco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Laufer, Natalia Lorna. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Quarleri, Jorge Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentin
Linear polyethylenimine-decorated gold nanoparticles: One-step electrodeposition and studies of interaction with viral and animal proteins
Polyethylenimine (PEI)-decorated gold nanoparticles (AuNP) were electrodeposited on conductive surfaces in one-step procedure. Solution-state NMR evidenced that chloride from PEI.HCl was partially exchanged by AuCl 4 − prior to AuNP formation. XPS studies indicated the presence of Au° together with the interaction between AuNP with nitrogen atoms of the PEI polymer. The particle size by DLS was 49 nm. The electrochemical behavior of bare electrode and of glassy carbon electrode modified with PEI-decorated AuNP was compared using [Fe(CN) 6 ] 3-/4- redox probe, to determine the potential role of the nanomaterial and of the polymer in the detection of proteins. The most relevant experimental variables from cyclic voltammetry (CV), square-wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) were used for the characterization of protein uptake. The adsorption by electrostatic interaction between the biomolecules and the positively charged polymer (PEIH + ) affected negatively the current response (Ip) of the probe, especially when the negatively charged protein was involved. This platform resulted adequate to immobilize proteins and to characterize this process, for further applications as a tool in bioanalysis or biotechnology.Fil: Lazaro Martinez, Juan Manuel. Universidad de Málaga; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Byrne, Agustin Jesus. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Rodríguez Castellón, Enrique. Universidad de Málaga; EspañaFil: Manrique, Julieta Marina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Trelew. Laboratorio de Virología y Genética Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Jones, Leandro Roberto. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Trelew. Laboratorio de Virología y Genética Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Campodallorto, Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentin
Genomic analysis of bovine herpesvirus type 4 (BoHV-4) from Argentina: High genetic variability and novel phylogenetic groups
Bovine herpesvirus 4 (BoHV-4) is a γ-herpesvirus that has been isolated both from apparently healthy animals and from cattle with a variety of clinical signs, including post-partum endometritis and abortion. BoHV-4 causes either a persistent or a latent infection in cells of the monocyte/macrophage lineage. Two groups of BoVH-4 strains have been defined based on their restriction patterns: the Movar-like strains (European prototype) and the DN 599-like strains (American prototype). The purpose of the present study was to genetically characterize wild type BoHV-4 strains isolated from vaginal discharges of aborted cows in Argentina. The virus was identified by isolation and nested PCR in all vaginal discharge samples from aborted cows, either as a sole agent or in association with other pathogens. Restriction enzyme profiling and phylogenetic analysis demonstrated that there is a high genetic variability among the studied field isolates. The existence of three groups of strains, which were designated as genotypes 1, 2 and 3, is described. Genotypes 1 and 2 possibly correspond to the Movar-like and DN 599-like groups, respectively, whereas Genotype 3 corresponds to a novel group. Two viral strains did not cluster into any of these three groups, indicating that other genotypes could be circulating in Argentina. These results suggest a complex epidemiological background for the Argentinean BoHV-4 strains, probably influenced by independent events of genetic drift. This hypothesis cannot be rejected based on the available data. However, there is no direct evidence supporting this possibility. Thus, it seems speculative to suggest that interspecific jumps are responsible for the observed phylogenetic grouping. On the other hand, our analyses suggest a geographical structure for the observed viral genotypes, since genotypes 1 and 2 included the European (Movar-like) and American (DN599-like) reference strains, respectively. Geographic dispersion is known to be a driver of herpes viruses diversification, and independent evolution in geographical isolated places ensures the emergence of particular mutations in each location due to genetic drift (Compans, 2007; Zong et al., 1999). Therefore, at this point, the genetic drift hypothesis is the one that requires less ad-hoc considerations and thus, to our understanding, is the one that fits to the findings from this study. The involvement of this genetic variability in the detection and pathogenesis of BoHV-4 remains to be investigated.Fil: Verna, Andrea Elizabeth. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Manrique, Julieta Marina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Playa Unión. Estación de Fotobiología Playa Unión; ArgentinaFil: Pérez, Sandra Elizabeth. Universidad Nacional del Centro de la Provincia de Buenos Aires; ArgentinaFil: Leunda, M. R.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; ArgentinaFil: Pereyra, Susana Beatriz. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; ArgentinaFil: Jones, Leandro Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Playa Unión. Estación de Fotobiología Playa Unión; ArgentinaFil: Odeón, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; Argentin
Concomitant infection of Neospora caninum and Bovine Herpesvirus type 5 in spontaneous bovine abortions1
Bovine Herpesvirus type 5 (BoHV-5) has not been conclusively demonstrated to cause bovine abortion. Brain lesions produced by Neospora caninum and Bovine Herpesvirus type 1 (BoHV-1) exhibit common features. Therefore, careful microscopic evaluation and additional diagnostic procedures are required to achieve an accurate final etiological diagnosis. The aim of the present work was to investigate the occurrence of infections due to BoHV-1, BoHV-5 and N. caninum in 68 cases of spontaneous bovine abortions which showed microscopic lesions in the fetal central nervous system. This study allowed the identification of 4 (5.9%) fetuses with dual infection by BoHV-5 and N. caninum and 33 (48.5%) cases in which N. caninum was the sole pathogen identified. All cases were negative to BoHV-1. The results of this study provide evidence that dual infection by BoHV-5 and N. caninum occur during pregnancy in cattle; however, the role of BoHV-5 as a primary cause of bovine abortion needs further research. Molecular diagnosis of BoHV-5 and N. caninum confirmed the importance of applying complementary assays to improve the sensitivity of diagnosing bovine abortion.Fil: Marin, Maia Solange. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires. Estación Experimental Agropecuaria Balcarce; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina;Fil: Morrell, Eleonora Lidia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires. Estación Experimental Agropecuaria Balcarce; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina;Fil: Perez, Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina;Fil: Leunda, Maria R.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires. Estación Experimental Agropecuaria Balcarce; Argentina;Fil: Moore, Dadin Prando. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires. Estación Experimental Agropecuaria Balcarce; Argentina;Fil: Jones, Leandro Roberto. Fund.Playa Union. Estacion de Fotobiologia Playa Union; Argentina;Fil: Campero, Carlos Manuel. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires. Estación Experimental Agropecuaria Balcarce; Argentina;Fil: Odeon, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires. Estación Experimental Agropecuaria Balcarce; Argentina
Molecular Characterization of the First Bovine Herpesvirus 4 (BoHV-4) Strains Isolated from In Vitro Bovine Embryos production in Argentina
Bovine herpesvirus 4 (BoHV-4) is increasingly considered as responsible for various problems of the reproductive tract. The virus infects mainly blood mononuclear cells and displays specific tropism for vascular endothelia, reproductive and fetal tissues. Epidemiological studies suggest its impact on reproductive performance, and its presence in various sites in the reproductive tract highlights its potential transmission in transfer-stage embryos. This work describes the biological and genetic characterization of BoHV-4 strains isolated from an in vitro bovine embryo production system. BoHV-4 strains were isolated in 2011 and 2013 from granulosa cells and bovine oocytes from ovary batches collected at a local abattoir, used as “starting material” for in vitro production of bovine embryos. Compatible BoHV-4-CPE was observed in the co-culture of granulosa cells and oocytes with MDBK cells. The identity of the isolates was confirmed by PCR assays targeting three ORFs of the viral genome. The phylogenetic analyses of the strains suggest that they were evolutionary unlinked. Therefore it is possible that BoHV-4 ovary infections occurred regularly along the evolution of the virus, at least in Argentina, which can have implications in the systems of in vitro embryo production. Thus, although BoHV-4 does not appear to be a frequent risk factor for in vitro embryo production, data are still limited. This study reveals the potential of BoHV-4 transmission via embryo transfer. Moreover, the high variability among the BoHV-4 strains isolated from aborted cows in Argentina highlights the importance of further research on the role of this virus as an agent with the potential to cause reproductive disease in cattle. The genetic characterization of the isolated strains provides data to better understand the pathogenesis of BoHV-4 infections. Furthermore, it will lead to fundamental insights into the molecular aspects of the virus and the means by which these strains circulate in the herds.EEA BalcarceFil: Gonzalez Altamiranda, Erika Analia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Manrique, Julieta Marina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Perez, Sandra. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rios, Glenda Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Odeón, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Leunda, Maria Rosa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Jones, Leandro Roberto. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Verna, Andrea Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentin
Nuisance <i>Didymosphenia geminata</i> blooms in the Argentinean Patagonia : Status and current research trends
Large nuisance blooms of Didymosphenia geminata have become increasingly widespread in Patagonia. Although the first published account for South America was in 1964, reports of large growths in Chile and Argentina commenced around 2010. Since then, these blooms have been observed all along the Andes region to the south of parallel 42 S. General surveys are needed to help provide an explanation. Possibilities include one or more new genetic variants or responses of local populations to global environmental changes. Electron microscopy of material from the Argentinean Patagonia revealed marked differences between regions, though it is unclear how much local factors and/or variations in life cycle contribute. Thus, we are approaching the problem from a molecular perspective, which we hope will help to overcome this limitation. Initial studies showed that D. geminata seems to be highly recalcitrant to DNA extraction, thus hindering the survey of molecular markers. We have now developed an improved DNA extraction technique for Didymosphenia mats, which markedly outperforms other techniques. However, endpoint polymerase chain reaction analyses suggest the persistence of polymerase chain reaction inhibitors in the samples, highlighting the need of further improvements for quantitative studies.Facultad de Ciencias Naturales y Muse
BLOOM: A 176B-Parameter Open-Access Multilingual Language Model
Large language models (LLMs) have been shown to be able to perform new tasks
based on a few demonstrations or natural language instructions. While these
capabilities have led to widespread adoption, most LLMs are developed by
resource-rich organizations and are frequently kept from the public. As a step
towards democratizing this powerful technology, we present BLOOM, a
176B-parameter open-access language model designed and built thanks to a
collaboration of hundreds of researchers. BLOOM is a decoder-only Transformer
language model that was trained on the ROOTS corpus, a dataset comprising
hundreds of sources in 46 natural and 13 programming languages (59 in total).
We find that BLOOM achieves competitive performance on a wide variety of
benchmarks, with stronger results after undergoing multitask prompted
finetuning. To facilitate future research and applications using LLMs, we
publicly release our models and code under the Responsible AI License
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