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Marta?G. Lete Jesus Sot David Gil Mikel Valle Milagros Medina Felix?M. Go?i Alicia Alonso 《Biophysical journal》2015,108(4):863-871
In a previous article, we demonstrated that histones (H1 or histone octamers) interact with negatively charged bilayers and induce extensive aggregation of vesicles containing phosphatidylinositol-4-phosphate (PIP) and, to a lesser extent, vesicles containing phosphatidylinositol (PI). Here, we found that vesicles containing PIP, but not those containing PI, can undergo fusion induced by histones. Fusion was demonstrated through the observation of intervesicular mixing of total lipids and inner monolayer lipids, and by ultrastructural and confocal microscopy studies. Moreover, in both PI- and PIP-containing vesicles, histones caused permeabilization and release of vesicular aqueous contents, but the leakage mechanism was different (all-or-none for PI and graded release for PIP vesicles). These results indicate that histones could play a role in the remodeling of the nuclear envelope that takes place during the mitotic cycle. 相似文献
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Milagros León-Barrios Juan Pérez-Yépez Paola Dorta Ana Garrido Concepción Jiménez 《Systematic and applied microbiology》2017,40(3):171-178
Lotus lancerottensis is an endemic species that grows widely throughout Lanzarote Island (Canary Is.). Characterization of 48 strains isolated from root nodules of plants growing in soils from eleven locations on the island showed that 38 isolates (79.1%) belonged to the species Sinorhizobium meliloti, whereas only six belonged to Mesorhizobium sp., the more common microsymbionts for the Lotus. Other genotypes containing only one isolate were classified as Pararhizobium sp., Sinorhizobium sp., Phyllobacterium sp. and Bradyrhizobium-like. Strains of S. meliloti were distributed along the island and, in most of the localities they were exclusive or major microsymbionts of L. lancerottensis. Phylogeny of the nodulation nodC gene placed the S. meliloti strains within symbiovar lancerottense and the mesorhizobial strains with the symbiovar loti. Although strains from both symbiovars produced effective N2-fixing nodules, S. meliloti symbiovar lancerottense was clearly the predominant microsymbiont of L. lancerottensis. This fact correlated with the better adaptation of strains of this species to the alkaline soils of Lanzarote, as in vitro characterization showed that while the mesorhizobial strains were inhibited by alkaline pH, S. meliloti strains grew well at pH 9. 相似文献
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Milagros Salas-Prato Jean-Francois Tanguay Yves Lefebvre Don Wojciechowicz H. Heng Liem David W. Barnes Ginette Ouellette Ursula Muller-Eberhard 《In vitro cellular & developmental biology. Plant》1988,24(3):230-238
Summary We established for human fetal liver cells (cultured for 2 wk) in a hormonally defined medium, optimal conditions for attachment,
multiplication, and preservation of epithelial morphology as well as production and secretion of serum proteins characteristic
of fetal (α1-fetoprotein, AFP) and adult (albumin and hemopexin) life. Conditions were considered optimal when cell number,
albumin, and hemopexin levels were maintained throughout the 2-wk culture period. However, the decrease in AFP concentration,
which occurred after a few days of culture, could not be reversed. The culture system developed is a suitable model for studying
regulatory mechanisms governing structure and function during differentiation and may prove useful for testing the effect
of toxic agents during fetal development of the human liver.
This work was supported by the Medical Research Council of Canada (Grant MA-7768), a grant from the “Fonds de la recherche
en sante du Quebec” (F.R.S.Q.) and by “CAFIR” funds from the University of Montreal. David W. Barnes is supported by NIH-NCI-grants
40475 and 01226. MS-P was recipient of a scholarship from the Notre-Dame Hospital Foundation and from the Universite de Montreal.J-FT
received a summer studentship from the FRSQ and from the Canadian Liver Foundation.
Presented in preliminary form at the Tissue Culture Meeting in Houston, June 1984. 相似文献
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An extensive neuroimaging literature has helped characterize the brain regions involved in navigating a spatial environment. Far less is known, however, about the brain networks involved when learning a spatial layout from a cartographic map. To compare the two means of acquiring a spatial representation, participants learned spatial environments either by directly navigating them or learning them from an aerial-view map. While undergoing functional magnetic resonance imaging (fMRI), participants then performed two different tasks to assess knowledge of the spatial environment: a scene and orientation dependent perceptual (SOP) pointing task and a judgment of relative direction (JRD) of landmarks pointing task. We found three brain regions showing significant effects of route vs. map learning during the two tasks. Parahippocampal and retrosplenial cortex showed greater activation following route compared to map learning during the JRD but not SOP task while inferior frontal gyrus showed greater activation following map compared to route learning during the SOP but not JRD task. We interpret our results to suggest that parahippocampal and retrosplenial cortex were involved in translating scene and orientation dependent coordinate information acquired during route learning to a landmark-referenced representation while inferior frontal gyrus played a role in converting primarily landmark-referenced coordinates acquired during map learning to a scene and orientation dependent coordinate system. Together, our results provide novel insight into the different brain networks underlying spatial representations formed during navigation vs. cartographic map learning and provide additional constraints on theoretical models of the neural basis of human spatial representation. 相似文献
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Fossette S Girard C López-Mendilaharsu M Miller P Domingo A Evans D Kelle L Plot V Prosdocimi L Verhage S Gaspar P Georges JY 《PloS one》2010,5(11):e13908