Search results for "mammalia"
showing 10 items of 304 documents
Silencing of hepatic fate-conversion factors induce tumorigenesis in reprogrammed hepatic progenitor-like cells
2016
Abstract Background Several studies have reported the direct conversion of mouse fibroblasts to hepatocyte-like cells with different degrees of maturation by expression of hepatic fate-conversion factors. Methods We have used a combination of lentiviral vectors expressing hepatic fate-conversion factors with Oct4, Sox2, Klf4, and Myc to convert mouse embryonic fibroblasts into hepatic cells. Results We have generated hepatic cells with progenitor-like features (iHepL cells). iHepL cells displayed basic hepatocyte functions but failed to perform functions characteristic of mature hepatocytes such as significant Cyp450 or urea cycle activities. iHepL cells expressed multiple hepatic-specific …
A screen for constituents of motor control and decision making in Drosophila reveals visual distance-estimation neurons
2016
AbstractClimbing over chasms larger than step size is vital to fruit flies, since foraging and mating are achieved while walking. Flies avoid futile climbing attempts by processing parallax-motion vision to estimate gap width. To identify neuronal substrates of climbing control, we screened a large collection of fly lines with temporarily inactivated neuronal populations in a novel high-throughput assay described here. The observed climbing phenotypes were classified; lines in each group are reported. Selected lines were further analysed by high-resolution video cinematography. One striking class of flies attempts to climb chasms of unsurmountable width; expression analysis guided us to C2 …
Androgen-inducible gene 1 increases the ER Ca(2+) content and cell death susceptibility against oxidative stress.
2016
Androgen-induced gene 1 (AIG1) is a transmembrane protein implicated with survival (its expression level was shown to correlate with the survival of patients suffering from hepatocellular carcinoma) and Ca(2+) signaling (over-expression of AIG1 increased transcription mediated by the Ca(2+)-dependent nuclear factor of activated T cells). We aimed to shed light on this less-studied protein and investigated its tissue expression, genomic organization, intracellular localization and membrane topology as well as its effects on cell death susceptibility and the Ca(2+) content of the endoplasmic reticulum. Immunoblotting of mouse tissues demonstrated highest expression of AIG1 in the liver, lung …
Mitochondria during sea urchin oogenesis.
2017
SummarySea urchin represents an ideal model for studies on fertilization and early development, but the achievement of egg competence and mitochondrial behaviour during oogenesis remain to be enlightened. Oocytes of echinoid, such as sea urchin, unlike other echinoderms and other systems, complete meiotic maturation before fertilization. Mitochondria, the powerhouse of eukaryotic cells, contain a multi-copy of the maternally inherited genome, and are involved directly at several levels in the reproductive processes, as their functional status influences the quality of oocytes and contributes to fertilization and embryogenesis. In the present paper, we report our latest data on mitochondrial…
TOX3 regulates neural progenitor identity
2016
The human genomic locus for the transcription factor TOX3 has been implicated in susceptibility to restless legs syndrome and breast cancer in genome-wide association studies, but the physiological role of TOX3 remains largely unknown. We found Tox3 to be predominantly expressed in the developing mouse brain with a peak at embryonic day E14 where it co-localizes with the neural stem and progenitor markers Nestin and Sox2 in radial glia of the ventricular zone and intermediate progenitors of the subventricular zone. Tox3 is also expressed in neural progenitor cells obtained from the ganglionic eminence of E15 mice that express Nestin, and it specifically binds the Nestin promoter in chromati…
Engineering of Adult Neurogenesis and Gliogenesis
2016
Neural stem/progenitor cells (NSPCs) retain their ability to generate newborn neurons throughout life in the mammalian brain. Here, we describe how recently developed virus- and transgenesis-based techniques will help us (1) to understand the functional effects of neurogenesis in health and disease, (2) to design novel approaches to harness the potential for NSPC-associated endogenous repair, and (3) to induce the generation of neurons outside the main neurogenic niches in the adult brain.
Influence of Polyplex Formation on the Performance of Star-Shaped Polycationic Transfection Agents for Mammalian Cells
2016
Genetic modification (“transfection”) of mammalian cells using non-viral, synthetic agents such as polycations, is still a challenge. Polyplex formation between the DNA and the polycation is a decisive step in such experiments. Star-shaped polycations have been proposed as superior transfection agents, yet have never before been compared side-by-side, e.g., in view of structural effects. Herein four star-shaped polycationic structures, all based on (2-dimethylamino) ethyl methacrylate (DMAEMA) building blocks, were investigated for their potential to deliver DNA to adherent (CHO, L929, HEK-293) and non-adherent (Jurkat, primary human T lymphocytes) mammalian cells. The investigated vectors …
Lymphatic Endothelial Cells Control Initiation of Lymph Node Organogenesis
2017
Lymph nodes (LNs) are strategically situated throughout the body at junctures of the blood vascular and lymphatic systems to direct immune responses against antigens draining from peripheral tissues. The current paradigm describes LN development as a programmed process that is governed through the interaction between mesenchymal lymphoid tissue organizer (LTo) cells and hematopoietic lymphoid tissue inducer (LTi) cells. Using cell-type-specific ablation of key molecules involved in lymphoid organogenesis, we found that initiation of LN development is dependent on LTi-cell-mediated activation of lymphatic endothelial cells (LECs) and that engagement of mesenchymal stromal cells is a succeedi…
Evolutionary insight on localization of 18S, 28S rDNA genes on homologous chromosomes in Primates genomes
2018
Abstract We explored the topology of 18S and 28S rDNA units by fluorescence in situ hybridization (FISH) in the karyotypes of thirteen species representatives from major groups of Primates and Tupaia minor (Günther, 1876) (Scandentia), in order to expand our knowledge of Primate genome reshuffling and to identify the possible dispersion mechanisms of rDNA sequences. We documented that rDNA probe signals were identified on one to six pairs of chromosomes, both acrocentric and metacentric ones. In addition, we examined the potential homology of chromosomes bearing rDNA genes across different species and in a wide phylogenetic perspective, based on the DAPI-inverted pattern and their synteny t…
Autophagy as a defense strategy against stress: focus on Paracentrotus lividus sea urchin embryos exposed to cadmium
2015
Autophagy is used by organisms as a defense strategy to face environmental stress. This mechanism has been described as one of the most important intracellular pathways responsible for the degradation and recycling of proteins and organelles. It can act as a cell survival mechanism if the cellular damage is not too extensive or as a cell death mechanism if the damage/stress is irreversible; in the latter case, it can operate as an independent pathway or together with the apoptotic one. In this review, we discuss the autophagic process activated in several aquatic organisms exposed to different types of environmental stressors, focusing on the sea urchin embryo, a suitable system recently in…