The germline ecotropic murine leukemia (MuLV) proviruses of BALB/c and C57BL/6 (B6) mice were analyzed to determine the molecular basis of low virus expression in these mouse strains and to determine the mechanism of interaction of these two proviruses. Previous work had demonstrated that the BALB/c endogenous ecotropic provirus was infectious but unable to induce XC cell syncytia formation, and that induced (BALB/c X B6) hybrid cells expressed 10- to 50-fold more XC syncytia than induced parental cells. Two independently isolated DNA clones of the B6 endogenous ecotropic provirus were noninfectious following transfection into cells, and cell lines that expressed this viral genome produced noninfectious MuLV. Nucleotide sequencing of the mutant region of the B6 provirus indicated that the defective nature of this provirus resulted from an amino acid substitution of proline for alanine in the central portion of reverse transcriptase. From the analysis of the virus produced by induced hybrid cells, and the patterns of steady-state viral RNA in induced cells, we propose that the enhanced XC cell syncytia formation observed in hybrid cells is due to trans-complementation of viral proteins and not viral recombination or trans-activation of viral genome expression.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/0042-6822(88)90388-1 | DOI Listing |
Neuro Oncol
January 2025
Department of Neurosurgery, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg.
Background: Peripheral nerve sheath tumors (PNSTs) encompass entities with different cellular differentiation and degrees of malignancy. Spatial heterogeneity complicates diagnosis and grading of PNSTs in some cases. In malignant PNST (MPNST) for example, single cell sequencing data has shown dissimilar differentiation states of tumor cells.
View Article and Find Full Text PDFBull Math Biol
January 2025
Section of Epidemiology, University of Copenhagen, Copenhagen, Denmark.
Using genetic data to infer evolutionary distances between molecular sequence pairs based on a Markov substitution model is a common procedure in phylogenetics, in particular for selecting a good starting tree to improve upon. Many evolutionary patterns can be accurately modelled using substitution models that are available in closed form, including the popular general time reversible model (GTR) for DNA data. For more complex biological phenomena, such as variations in lineage-specific evolutionary rates over time (heterotachy), other approaches such as the GTR with rate variation (GTR ) are required, but do not admit analytical solutions and do not automatically allow for likelihood calculations crucial for Bayesian analysis.
View Article and Find Full Text PDFJ Dev Biol
December 2024
Department of Neuroscience, Biomedicine and Movement-Sec. Anatomy and Histology, University of Verona, Via Le Grazie 8, 37134 Verona, Italy.
Since its first conceptualization over a century ago, the mesenchymal phenotype has traditionally been viewed as either a transient phase between successive epithelial stages or as a feature of cell types primarily devoted to structural support. However, recent findings in cancer research challenge this limited view, demonstrating that mesenchymal traits and hybrid mesenchymal/epithelial states can mark cancer cells with stem cell properties. By analyzing publicly available single-cell transcriptome datasets from early embryonic stages and adult tissues, this study aims to extend this concept beyond pathological contexts, suggesting that a partial or fully mesenchymal phenotype may represent the morphological expression of undifferentiated and multipotent states in both the developing embryo and adult organs.
View Article and Find Full Text PDFLangmuir
January 2025
College of Materials Science and Engineering, Sichuan University, Chengdu 610064, China.
Metallic Zn is a promising anode for high-safety, low-cost, and large-scale energy storage systems. However, it is strongly hindered by unstable electrode/electrolyte interface issues, including zinc dendrite, corrosion, passivation, and hydrogen evolution reactions. In this work, an in situ interface protection strategy is established by turning the corrosion/passivation byproducts (zinc hydroxide sulfates, ZHSs) into a stable hybrid protection layer.
View Article and Find Full Text PDFBBA Adv
December 2024
Genos Glycoscience Research Laboratory, 10000 Zagreb, Croatia.
Down syndrome (DS), a genetic condition caused by trisomy 21 (T21), manifests various neurological symptoms, including intellectual disability, early neurodegeneration, and early-onset dementia. N-glycosylation is a protein modification that plays a critical role in numerous neurobiological processes and whose dysregulation is associated with a range of neurological disorders. However, whether N-glycosylation of neural glycoproteins is affected in DS has not been studied.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!