排序方式: 共有39条查询结果,搜索用时 15 毫秒
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Mason HA Rakowiecki SM Raftopoulou M Nery S Huang Y Gridley T Fishell G 《Development (Cambridge, England)》2005,132(19):4247-4258
Numerous lines of evidence suggest that Notch signaling plays a pivotal role in controlling the production of neurons from progenitor cells. However, most experiments have relied on gain-of-function approaches because perturbation of Notch signaling results in death prior to the onset of neurogenesis. Here, we examine the requirement for Notch signaling in the development of the striatum through the analysis of different single and compound Notch1 conditional and Notch3 null mutants. We find that normal development of the striatum depends on the presence of appropriate Notch signals in progenitors during a critical window of embryonic development. Early removal of Notch1 prior to neurogenesis alters early-born patch neurons but not late-born matrix neurons in the striatum. We further show that the late-born striatal neurons in these mutants are spared as a result of functional compensation by Notch3. Notably, however, the removal of Notch signaling subsequent to cells leaving the germinal zone has no obvious effect on striatal organization and patterning. These results indicate that Notch signaling is required in neural progenitor cells to control cell fate in the striatum, but is dispensable during subsequent phases of neuronal migration and differentiation. 相似文献
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Kostas Kampourakis Eirini Palaiokrassa Maria Papadopoulou Vasiliki Pavlidi Myrto Argyropoulou 《Evolution》2012,5(2):279-291
Research has shown that children usually provide teleological explanations for the features of organisms and artifacts, from
a very early age (3–4 years old). However, there is no consensus on whether teleological explanations are given in the same
manner for non-living natural objects as well. The present study aimed to document the teleological explanations of 5- to
8-year-old children for particular features (color and shape) of organisms, artifacts and non-living natural objects. In addition,
it was examined if there was any correlation between these explanations and children’s explanations for the usefulness of
those features. Our results indicate a developmental shift in children’s teleological explanations, from a non-selective teleology
in pre-school to a selective one in the second grade. In the latter case, children provided teleological explanations mostly
for the shape of the feet of organisms and for the shape of artifacts, whereas pre-school children provided teleological explanations
for non-living natural objects as well, both for the color and for the shape in all cases. Our results are not conclusive
and further research is required, including a larger spectrum of students, since teleology is one of the most important conceptual
obstacles in understanding evolution that persists even into adulthood. We conclude by proposing a particular research program
for this purpose. 相似文献
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Bastian Schiffthaler Myrto Kostadima NGS Trainer Consortium Nicolas Delhomme Gabriella Rustici 《PLoS computational biology》2016,12(6)
The advancement of high-throughput sequencing (HTS) technologies and the rapid development of numerous analysis algorithms and pipelines in this field has resulted in an unprecedentedly high demand for training scientists in HTS data analysis. Embarking on developing new training materials is challenging for many reasons. Trainers often do not have prior experience in preparing or delivering such materials and struggle to keep them up to date. A repository of curated HTS training materials would support trainers in materials preparation, reduce the duplication of effort by increasing the usage of existing materials, and allow for the sharing of teaching experience among the HTS trainers’ community. To achieve this, we have developed a strategy for materials’ curation and dissemination. Standards for describing training materials have been proposed and applied to the curation of existing materials. A Git repository has been set up for sharing annotated materials that can now be reused, modified, or incorporated into new courses. This repository uses Git; hence, it is decentralized and self-managed by the community and can be forked/built-upon by all users. The repository is accessible at http://bioinformatics.upsc.se/htmr. 相似文献
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Cheong SC Blangenois I Franssen JD Servais C Phan V Trakatelli M Bruyns C Vile R Velu T Brandenburger A 《The journal of gene medicine》2006,8(7):919-928
BACKGROUND: Hybrids obtained by fusion between tumour cells (TC) and dendritic cells (DC) have been proposed as anti-tumour vaccines because of their potential to combine the expression of tumour-associated antigens with efficient antigen presentation. The classical methods used for fusion, polyethylene glycol (PEG) and electrofusion, are cytotoxic and generate cell debris that can be taken up by DC rendering the identification of true hybrids difficult. METHODS: We have established a stable cell line expressing a viral fusogenic membrane glycoprotein (FMG) that is not itself susceptible to fusion. This cell line has been used to generate hybrids and to evaluate the relevance of tools used for hybrid detection. RESULTS: This FMG-expressing cell line promotes fusion between autologous or allogeneic TC and DC in any combination, generating 'tri-parental hybrids'. At least 20% of TC are found to be integrated into hybrids. CONCLUSIONS: It is speculated that this tri-parental hybrid approach offers new possibilities to further modulate the anti-tumour effect of the DC/TC hybrids since it allows the expression of relevant immunostimulatory molecules by appropriate engineering of the fusogenic cell line. 相似文献
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Mansoor A Mazhar K Khaliq S Hameed A Rehman S Siddiqi S Papaioannou M Cavalli-Sforza LL Mehdi SQ Ayub Q 《Human genetics》2004,114(5):484-490
Three populations from northern Pakistan, the Burusho, Kalash, and Pathan, claim descent from soldiers left behind by Alexander the Great after his invasion of the Indo-Pak subcontinent. In order to investigate their genetic relationships, we analyzed nine Alu insertion polymorphisms and 113 autosomal microsatellites in the extant Pakistani and Greek populations. Principal component, phylogenetic, and structure analyses show that the Kalash are genetically distinct, and that the Burusho and Pathan populations are genetically close to each other and the Greek population. Admixture estimates suggest a small Greek contribution to the genetic pool of the Burusho and Pathan and demonstrate that these two northern Pakistani populations share a common Indo-European gene pool that probably predates Alexanders invasion. The genetically isolated Kalash population may represent the genetic pool of ancestral Eurasian populations of Central Asia or early Indo-European nomadic pastoral tribes that became sequestered in the valleys of the Hindu Kush Mountains. 相似文献
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Mazouz N Detournay O Buelens C Renneson J Trakatelli M Lambermont M Goldman M Toungouz M 《Cancer immunology, immunotherapy : CII》2005,54(10):1010-1017
Despite limited clinical efficacy in large trials, dendritic cells (DC)-based immunization has yielded impressive responses in some patients. Key questions remain to be solved in order to optimize this therapeutic vaccine. Among them, the nature of the DC type used and its state of maturation are pivotal. Besides myeloid DC which are mostly used in clinical trials, a new DC type has been recently described resulting from the differentiation of monocytes in the presence of type I IFNs. In the present study, we analyze the features of type I IFNs DC generated in the presence of either IL-3 (IL-3-DC) or GM-CSF (GM-CSF-DC) and compare their capacity to respond to poly(I:C) and to subsequently trigger T-cell activation. The two DC types disclose a similar immunophenotype characterized by high levels of chemokines receptors, co-stimulatory and HLA molecules expression. After poly(I:C) maturation, both DC types display a marked upregulation of CD80, CD83 and CD86 and the same pattern of gene expression. In addition, poly(I:C) stimulated them to secrete IFN- and IL-12p70. Both DC types elicit potent allogeneic reactions. Priming of autologous T cells by IL-3-DC or GM-CSF-DC pulsed with an HLA-A2 restricted melan-A derived peptide, lead to the expansion of peptide specific CTL secreting high amounts of IFN-.We conclude that poly(I:C) matured IL-3-DC and GM-CSF-DC share similar phenotype and functional properties including the capacity to prime tumor-associated antigen specific CTL.N. Mazouz and O. Detournay equally contributed to this work. 相似文献