Search results for "030302 biochemistry & molecular biology"
showing 10 items of 238 documents
Variation in RNA virus mutation rates across host cells.
2014
It is well established that RNA viruses exhibit higher rates of spontaneous mutation than DNA viruses and microorganisms. However, their mutation rates vary amply, from 10−6 to 10−4 substitutions per nucleotide per round of copying (s/n/r) and the causes of this variability remain poorly understood. In addition to differences in intrinsic fidelity or error correction capability, viral mutation rates may be dependent on host factors. Here, we assessed the effect of the cellular environment on the rate of spontaneous mutation of the vesicular stomatitis virus (VSV), which has a broad host range and cell tropism. Luria-Delbrück fluctuation tests and sequencing showed that VSV mutated similarly…
Report of the IVth Workshop of the Spanish National Network on Mycotoxins and Toxigenic Fungi and Their Decontamination Processes (MICOFOOD), Held in…
2019
Ensiling is a practice commonly employed worldwide to preserve different kinds of crops for long periods of storage with similar nutritional values to the fresh materials. Since silages are one of the major components of the ruminant diet, these materials represent a potential source of mycotoxins as a consequence of the growth of filamentous fungi. The aim of this study was to analyse the presence of aflatoxins and Fusarium mycotoxins in different types of silages (maize, grass, alfalfa, sugar beet pulp, immature corn and ryegrass) collected in dairy farms located in four Spanish regions. Fungal populations, lactic acid bacteria, pH and water activity of the samples were also evaluated. Pe…
Expression of Drosophila Cabut during early embryogenesis, dorsal closure and nervous system development.
2010
cabut (cbt) encodes a transcription factor involved in Drosophila dorsal closure (DC), and it is expressed in embryonic epithelial sheets and yolk cell during this process upon activation of the Jun N-terminal kinase (JNK) signaling pathway. Additional studies suggest that cbt may have a role in multiple developmental processes. To analyze Cbt localization through embryogenesis, we generated a Cbt specific antibody that has allowed detecting new Cbt expression patterns. Immunohistochemical analyses on syncytial embryos and S2 cells reveal that Cbt is localized on the surface of mitotic chromosomes at all mitotic phases. During DC, Cbt is expressed in the yolk cell, in epidermal cells and in…
Assessment of Toxic Effects of Ochratoxin A in Human Embryonic Stem Cells
2019
Ochratoxin A (OTA) is a mycotoxin produced by different Aspergillus and Penicillium species, and it is considered a common contaminant in food and animal feed worldwide. On the other hand, human embryonic stem cells (hESCs) have been suggested as a valuable model for evaluating drug embryotoxicity. In this study, we have evaluated potentially toxic effects of OTA in hESCs. By using in vitro culture techniques, specific cellular markers, and molecular biology procedures, we found that OTA produces mild cytotoxic effects in hESCs by inhibiting cell attachment, survival, and proliferation in a dose-dependent manner. Thus, we suggest that hESCs provide a valuable human and cellular model for to…
Filipin labelling and intramembrane particles on the membranes of early and later autophagic vacuoles in Ehrlich ascites cells
1987
Cholesterol and intramembrane particle distribution on autophagic vacuole membranes was studied in Ehrlich ascites cells using filipin labelling and freeze-fracture electron microscopy. Unsaturated fatty acids were stained using imidazole-buffered osmium tetroxide. Autophagocytosis was induced with vinblastine, and early autophagic vacuoles were accumulated by lowering the ATP level in the cells with iodoacetate. Filipin labelling was observed in the limiting membranes of later, apparently hydrolase-containing autophagic vacuoles, whereas the most newly-formed, doublemembrane limited vacuoles were not labelled. The limiting membranes of late, residual body-type vacuoles either showed patchy…
Differential Expression of the Demosponge (Suberites domuncula) Carotenoid Oxygenases in Response to Light: Protection Mechanism Against the Self-Pro…
2012
The demosponge Suberites domuncula has been described to contain high levels of a proteinaceous toxin, Suberitine, that displays haemolytic activityIn the present study this 7–8 kDa polypeptide has been isolated and was shown to exhibit also cytotoxic effects on cells of the same species. Addition of retinal, a recently identified metabolite of β-carotene that is abundantly present in S. domuncula was found to reduce both the haemolytic and the cell toxic activity of Suberitine at a molar ratio of 1:1. Spectroscopic analyses revealed that the interaction between β-carotene and Suberitine can be ascribed to a reversible energy transfer reaction. The enzyme that synthesises retinal in the spo…
Distribution and Dynamics of Transcription-Associated Proteins during Parvovirus Infection
2012
ABSTRACT Canine parvovirus (CPV) infection leads to reorganization of nuclear proteinaceous subcompartments. Our studies showed that virus infection causes a time-dependent increase in the amount of viral nonstructural protein NS1 mRNA. Fluorescence recovery after photobleaching showed that the recovery kinetics of nuclear transcription-associated proteins, TATA binding protein (TBP), transcription factor IIB (TFIIB), and poly(A) binding protein nuclear 1 (PABPN1) were different in infected and noninfected cells, pointing to virus-induced alterations in binding dynamics of these proteins.
Parvovirus induced alterations in nuclear architecture and dynamics.
2009
The nucleus of interphase eukaryotic cell is a highly compartmentalized structure containing the three-dimensional network of chromatin and numerous proteinaceous subcompartments. DNA viruses induce profound changes in the intranuclear structures of their host cells. We are applying a combination of confocal imaging including photobleaching microscopy and computational methods to analyze the modifications of nuclear architecture and dynamics in parvovirus infected cells. Upon canine parvovirus infection, expansion of the viral replication compartment is accompanied by chromatin marginalization to the vicinity of the nuclear membrane. Dextran microinjection and fluorescence recovery after ph…
In vivo phage display: identification of organ-specific peptides using deep sequencing and differential profiling across tissues.
2021
Abstract In vivo phage display is widely used for identification of organ- or disease-specific homing peptides. However, the current in vivo phage biopanning approaches fail to assess biodistribution of specific peptide phages across tissues during the screen, thus necessitating laborious and time-consuming post-screening validation studies on individual peptide phages. Here, we adopted bioinformatics tools used for RNA sequencing for analysis of high-throughput sequencing (HTS) data to estimate the representation of individual peptides during biopanning in vivo. The data from in vivo phage screen were analyzed using differential binding—relative representation of each peptide in the target…
Therapeutic potential of alkaloids in autoimmune diseases: Promising candidates for clinical trials.
2020
Clinical investigations have characterized numerous disorders like autoimmune diseases, affecting the population at a rate of approximately 8-10%. These disorders are characterized by T-cell and auto-antibodies responses to self-molecules by immune system reactivity. Several therapeutic options have been adopted in clinics to combat such diseases, however, most of them are recurring. Thus, the discovery of new effective agents for the treatment of autoimmune diseases is paramount. In this context, natural products might be a useful alternative to the current therapies. Plant alkaloids with their substantial therapeutic history can be particularly interesting candidates for the alleviation o…