The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Klaus Brehm - One of the best experts on this subject based on the ideXlab platform.
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transient transfection of echinococcus multilocularis primary cells and complete in Vitro Regeneration of metacestode vesicles
International Journal for Parasitology, 2008Co-Authors: Markus Spiliotis, Sabrina Lechner, Dennis Tappe, Carsten Scheller, Georg Krohne, Klaus BrehmAbstract:Abstract A major limitation in studying molecular interactions between parasitic helminths and their hosts is the lack of suitable in Vitro cultivation systems for helminth cells and larvae. Here we present a method for long-term in Vitro cultivation of larval cells of the tapeworm Echinococcus multilocularis, the causative agent of alveolar echinococcosis. Primary cells isolated from cultivated metacestode vesicles in Vitro showed a morphology typical of Echinococcus germinal cells, displayed an Echinococcus-specific gene expression profile and a cestode-like DNA content of ∼300 Mbp. When kept under reducing conditions in the presence of Echinococcus vesicle fluid, the primary cells could be maintained in Vitro for several months and proliferated. Most interestingly, upon co-cultivation with host hepatocytes in a trans-well system, mitotically active Echinococcus cells formed cell aggregates that subsequently developed central cavities, surrounded by germinal cells. After 4 weeks, the cell aggregates gave rise to young metacestode vesicles lacking an outer laminated layer. This layer was formed after 6 weeks of cultivation indicating the complete in Vitro Regeneration of metacestode larvae. As an initial step toward the creation of a fully transgenic strain, we carried out transient transfection of Echinococcus primary cells using plasmids and obtained heterologous expression of a reporter gene. Furthermore, we successfully carried out targeted infection of Echinococcus cells with the facultatively intracellular bacterium Listeria monocytogenes, a DNA delivery system for genetic manipulation of mammalian cells. Taken together, the methods presented herein constitute important new tools for molecular investigations on host–parasite interactions in alveolar echinococcosis and on the roles of totipotent germinal cells in parasite Regeneration and metastasis formation. Moreover, they enable the development of fully transgenic techniques in this group of helminth parasites for the first time.
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transient transfection of echinococcus multilocularis primary cells and complete in Vitro Regeneration of metacestode vesicles
International Journal for Parasitology, 2008Co-Authors: Markus Spiliotis, Sabrina Lechner, Dennis Tappe, Carsten Scheller, Georg Krohne, Klaus BrehmAbstract:A major limitation in studying molecular interactions between parasitic helminths and their hosts is the lack of suitable in Vitro cultivation systems for helminth cells and larvae. Here we present a method for long-term in Vitro cultivation of larval cells of the tapeworm Echinococcus multilocularis, the causative agent of alveolar echinococcosis. Primary cells isolated from cultivated metacestode vesicles in Vitro showed a morphology typical of Echinococcus germinal cells, displayed an Echinococcus-specific gene expression profile and a cestode-like DNA content of approximately 300Mbp. When kept under reducing conditions in the presence of Echinococcus vesicle fluid, the primary cells could be maintained in Vitro for several months and proliferated. Most interestingly, upon co-cultivation with host hepatocytes in a trans-well system, mitotically active Echinococcus cells formed cell aggregates that subsequently developed central cavities, surrounded by germinal cells. After 4 weeks, the cell aggregates gave rise to young metacestode vesicles lacking an outer laminated layer. This layer was formed after 6 weeks of cultivation indicating the complete in Vitro Regeneration of metacestode larvae. As an initial step toward the creation of a fully transgenic strain, we carried out transient transfection of Echinococcus primary cells using plasmids and obtained heterologous expression of a reporter gene. Furthermore, we successfully carried out targeted infection of Echinococcus cells with the facultatively intracellular bacterium Listeria monocytogenes, a DNA delivery system for genetic manipulation of mammalian cells. Taken together, the methods presented herein constitute important new tools for molecular investigations on host-parasite interactions in alveolar echinococcosis and on the roles of totipotent germinal cells in parasite Regeneration and metastasis formation. Moreover, they enable the development of fully transgenic techniques in this group of helminth parasites for the first time.
Beatrice Ang’iyo Were - One of the best experts on this subject based on the ideXlab platform.
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in Vitro Regeneration of sesame sesamum indicum l from seedling cotyledon and hypocotyl explants
Plant Cell Tissue and Organ Culture, 2006Co-Authors: Anders S Carlsson, Beatrice Ang’iyo Were, Samuel Gudu, Augustino Osoro Onkware, Margareta WelanderAbstract:The goal of this study was to develop an efficient Regeneration protocol to be used for genetic transformation of sesame. Published Regeneration methods using benzyladenine (BA) and 1-naphthalene acetic acid (NAA) were unsuccessful for the cultivars used herein. Experiments were carried out using cotyledon and hypocotyl explants from the cultivar Mtwara-2. Later the optimised culture conditions were used to investigate the Regeneration response of different genotypes. There was significant interaction between hormone treatments and macronutrients for shoot and root Regeneration. Results also showed that shoot Regeneration was significantly influenced by explant type. Shoots were only obtained from cotyledons whereas both cotyledons and hypocotyls could produce roots. Modified Murashige and Skoog (MS) medium with N6 macronutrients resulted in twice the shoot Regeneration frequency obtained with ½MS macronutrients in the presence of thidiazuron (TDZ). The shoot Regeneration frequency was significantly reduced when BA was used in place of TDZ. On shoot Regeneration medium containing BA and NAA, only roots were formed. Replacing NAA with indole-3-acetic acid (IAA) greatly improved the Regeneration of shoots. The optimum growth regulator combination for shoot Regeneration was 20 μM TDZ together with 2.5 μM IAA, which gave a frequency of 63% and 4.4 shoots per regenerating explant for the best cultivar Ex-El. Genotypic differences were significant both for the number of explants regenerating shoots and the number of shoots produced per regenerating explant.
Douglas Andre Steinmacher - One of the best experts on this subject based on the ideXlab platform.
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a temporary immersion system improves in Vitro Regeneration of peach palm through secondary somatic embryogenesis
Annals of Botany, 2011Co-Authors: Douglas Andre Steinmacher, Miguel Pedro Guerra, Katja Saaresurminski, Reinhard LiebereiAbstract:Background and Aims Secondary somatic embryogenesis has been postulated to occur during induction of peach palm somatic embryogenesis. in the present study this morphogenetic pathway is described and a protocol for the establishment of cycling cultures using a temporary immersion system (TIS) is presented.
Margareta Welander - One of the best experts on this subject based on the ideXlab platform.
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in Vitro Regeneration of sesame sesamum indicum l from seedling cotyledon and hypocotyl explants
Plant Cell Tissue and Organ Culture, 2006Co-Authors: Anders S Carlsson, Beatrice Ang’iyo Were, Samuel Gudu, Augustino Osoro Onkware, Margareta WelanderAbstract:The goal of this study was to develop an efficient Regeneration protocol to be used for genetic transformation of sesame. Published Regeneration methods using benzyladenine (BA) and 1-naphthalene acetic acid (NAA) were unsuccessful for the cultivars used herein. Experiments were carried out using cotyledon and hypocotyl explants from the cultivar Mtwara-2. Later the optimised culture conditions were used to investigate the Regeneration response of different genotypes. There was significant interaction between hormone treatments and macronutrients for shoot and root Regeneration. Results also showed that shoot Regeneration was significantly influenced by explant type. Shoots were only obtained from cotyledons whereas both cotyledons and hypocotyls could produce roots. Modified Murashige and Skoog (MS) medium with N6 macronutrients resulted in twice the shoot Regeneration frequency obtained with ½MS macronutrients in the presence of thidiazuron (TDZ). The shoot Regeneration frequency was significantly reduced when BA was used in place of TDZ. On shoot Regeneration medium containing BA and NAA, only roots were formed. Replacing NAA with indole-3-acetic acid (IAA) greatly improved the Regeneration of shoots. The optimum growth regulator combination for shoot Regeneration was 20 μM TDZ together with 2.5 μM IAA, which gave a frequency of 63% and 4.4 shoots per regenerating explant for the best cultivar Ex-El. Genotypic differences were significant both for the number of explants regenerating shoots and the number of shoots produced per regenerating explant.
Reinhard Lieberei - One of the best experts on this subject based on the ideXlab platform.
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a temporary immersion system improves in Vitro Regeneration of peach palm through secondary somatic embryogenesis
Annals of Botany, 2011Co-Authors: Douglas Andre Steinmacher, Miguel Pedro Guerra, Katja Saaresurminski, Reinhard LiebereiAbstract:Background and Aims Secondary somatic embryogenesis has been postulated to occur during induction of peach palm somatic embryogenesis. in the present study this morphogenetic pathway is described and a protocol for the establishment of cycling cultures using a temporary immersion system (TIS) is presented.
