The Experts below are selected from a list of 104382 Experts worldwide ranked by ideXlab platform
Hiroshi Imai - One of the best experts on this subject based on the ideXlab platform.
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cell free extracts from mammalian oocytes partially induce nuclear reprogramming in Somatic Cells
Biology of Reproduction, 2009Co-Authors: Kei Miyamoto, Tomoyuki Tsukiyama, Naojiro Minami, Masayasu Yamada, Ning Li, Hiroshi ImaiAbstract:Nuclear transfer has been regarded as the only reliable tool for studying nuclear reprogramming of mammalian Somatic Cells by oocytes. However, nuclear transfer is not well suited for biochemical analyses of the molecular mechanisms of reprogramming. A cell-free system from oocytes is an attractive alternative way to mimic reprogramming in vitro, since a large number of Cells can be treated and analyzed. Nevertheless, a cell-free system using oocytes has not been developed in mammals. Here, cell extracts from porcine oocytes were prepared and their ability to induce nuclear reprogramming was evaluated. Extracts from metaphase II (MII) oocytes erased the machinery for regulating gene expression in reversibly permeabilized Somatic Cells. For example, the extracts caused histone deacetylation and the disappearance of TATA boxbinding protein from the nuclei. However, MII-extract-treated Cells did not show any obvious changes after cell culture. In contrast, extracts from germinal vesicle (GV) oocytes activated pluripotent marker genes, especially NANOG, and induced partial dedifferentiation after cell culture. The activation of pluripotent marker genes by GV extracts was associated with histone acetylation that was induced during extract treatment. These results indicate that GV- and MII-oocyte extracts have different roles on nuclear reprogramming. Furthermore, both oocyte extracts induced site-specific demethylation in the upstream region of NANOG. These results indicate that cellfree extracts derived from GV- and MII-oocytes could be useful for studying the mechanisms involved in nuclear reprogramming. cell-free extract, cell-free system, dedifferentiation, DNA methylation, extracts, gene regulation, histone acetylation, NANOG, oocyte, pig, reprogramming
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cell free extracts from mammalian oocytes partially induce nuclear reprogramming in Somatic Cells
Biology of Reproduction, 2009Co-Authors: Kei Miyamoto, Tomoyuki Tsukiyama, Naojiro Minami, Masayasu Yamada, Ning Li, Yang Yang, Hiroshi ImaiAbstract:Nuclear transfer has been regarded as the only reliable tool for studying nuclear reprogramming of mammalian Somatic Cells by oocytes. However, nuclear transfer is not well suited for biochemical analyses of the molecular mechanisms of reprogramming. A cell-free system from oocytes is an attractive alternative way to mimic reprogramming in vitro, since a large number of Cells can be treated and analyzed. Nevertheless, a cell-free system using oocytes has not been developed in mammals. Here, cell extracts from porcine oocytes were prepared and their ability to induce nuclear reprogramming was evaluated. Extracts from metaphase II (MII) oocytes erased the machinery for regulating gene expression in reversibly permeabilized Somatic Cells. For example, the extracts caused histone deacetylation and the disappearance of TATA boxbinding protein from the nuclei. However, MII-extract-treated Cells did not show any obvious changes after cell culture. In contrast, extracts from germinal vesicle (GV) oocytes activated pluripotent marker genes, especially NANOG, and induced partial dedifferentiation after cell culture. The activation of pluripotent marker genes by GV extracts was associated with histone acetylation that was induced during extract treatment. These results indicate that GV- and MII-oocyte extracts have different roles on nuclear reprogramming. Furthermore, both oocyte extracts induced site-specific demethylation in the upstream region of NANOG. These results indicate that cellfree extracts derived from GV- and MII-oocytes could be useful for studying the mechanisms involved in nuclear reprogramming. cell-free extract, cell-free system, dedifferentiation, DNA methylation, extracts, gene regulation, histone acetylation, NANOG, oocyte, pig, reprogramming
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reprogramming events of mammalian Somatic Cells induced by xenopus laevis egg extracts
Molecular Reproduction and Development, 2007Co-Authors: Kei Miyamoto, Naojiro Minami, Masayasu Yamada, Mari Ohnuki, Keita Ohsumi, Tadashi Furusawa, Sandeep Goel, Tomoyuki Tokunaga, Hiroshi ImaiAbstract:It is known that differentiated Cells can be reprogrammed to an undifferentiated state in oocyte cytoplasm after nuclear transfer. Recently, some reports suggested that Xenopus egg extracts have the ability to reprogram mammalian Somatic Cells. Reprogramming events of mammalian Cells after Xenopus egg extract treatment and after cell culture of extract-treated Cells have not been elucidated. In this experiment, we examined reprogramming events in reversibly permeabilized or nonpermeabilized porcine fibroblast Cells after Xenopus egg extract treatment. The Xenopus egg-specific histone B4 was assembled on porcine chromatin and nuclear lamin LIII was incorporated into nuclei. Deacetylation of histone H3 at lysine 9 in extract-treated Cells was detected in nonpermeabilized Cells, suggesting that a part of reprogramming may be induced even in nonpermeabilized Cells. Following culture of extract-treated Cells, the Cells began to express the pluripotent marker genes such as POU5F1 (OCT4) and SOX2 and to form colonies. Reactivation of the OCT4 gene in extract-treated Cells was also confirmed in bovine fibroblasts transformed with an OCT4-EGFP construct. These results suggest that nuclei of mammalian Cells can be partially reprogrammed to an embryonic state by Xenopus egg extracts and the remodeled Cells partly dedifferentiate after cell culture. A system using egg extracts may be useful for understanding the mechanisms and processes of dedifferentiation and reprogramming of mammalian Somatic Cells after nuclear transfer. Mol. Reprod. Dev. 74: 1268–1277, 2007. © 2007 Wiley-Liss, Inc.
Kei Miyamoto - One of the best experts on this subject based on the ideXlab platform.
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cell free extracts from mammalian oocytes partially induce nuclear reprogramming in Somatic Cells
Biology of Reproduction, 2009Co-Authors: Kei Miyamoto, Tomoyuki Tsukiyama, Naojiro Minami, Masayasu Yamada, Ning Li, Hiroshi ImaiAbstract:Nuclear transfer has been regarded as the only reliable tool for studying nuclear reprogramming of mammalian Somatic Cells by oocytes. However, nuclear transfer is not well suited for biochemical analyses of the molecular mechanisms of reprogramming. A cell-free system from oocytes is an attractive alternative way to mimic reprogramming in vitro, since a large number of Cells can be treated and analyzed. Nevertheless, a cell-free system using oocytes has not been developed in mammals. Here, cell extracts from porcine oocytes were prepared and their ability to induce nuclear reprogramming was evaluated. Extracts from metaphase II (MII) oocytes erased the machinery for regulating gene expression in reversibly permeabilized Somatic Cells. For example, the extracts caused histone deacetylation and the disappearance of TATA boxbinding protein from the nuclei. However, MII-extract-treated Cells did not show any obvious changes after cell culture. In contrast, extracts from germinal vesicle (GV) oocytes activated pluripotent marker genes, especially NANOG, and induced partial dedifferentiation after cell culture. The activation of pluripotent marker genes by GV extracts was associated with histone acetylation that was induced during extract treatment. These results indicate that GV- and MII-oocyte extracts have different roles on nuclear reprogramming. Furthermore, both oocyte extracts induced site-specific demethylation in the upstream region of NANOG. These results indicate that cellfree extracts derived from GV- and MII-oocytes could be useful for studying the mechanisms involved in nuclear reprogramming. cell-free extract, cell-free system, dedifferentiation, DNA methylation, extracts, gene regulation, histone acetylation, NANOG, oocyte, pig, reprogramming
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cell free extracts from mammalian oocytes partially induce nuclear reprogramming in Somatic Cells
Biology of Reproduction, 2009Co-Authors: Kei Miyamoto, Tomoyuki Tsukiyama, Naojiro Minami, Masayasu Yamada, Ning Li, Yang Yang, Hiroshi ImaiAbstract:Nuclear transfer has been regarded as the only reliable tool for studying nuclear reprogramming of mammalian Somatic Cells by oocytes. However, nuclear transfer is not well suited for biochemical analyses of the molecular mechanisms of reprogramming. A cell-free system from oocytes is an attractive alternative way to mimic reprogramming in vitro, since a large number of Cells can be treated and analyzed. Nevertheless, a cell-free system using oocytes has not been developed in mammals. Here, cell extracts from porcine oocytes were prepared and their ability to induce nuclear reprogramming was evaluated. Extracts from metaphase II (MII) oocytes erased the machinery for regulating gene expression in reversibly permeabilized Somatic Cells. For example, the extracts caused histone deacetylation and the disappearance of TATA boxbinding protein from the nuclei. However, MII-extract-treated Cells did not show any obvious changes after cell culture. In contrast, extracts from germinal vesicle (GV) oocytes activated pluripotent marker genes, especially NANOG, and induced partial dedifferentiation after cell culture. The activation of pluripotent marker genes by GV extracts was associated with histone acetylation that was induced during extract treatment. These results indicate that GV- and MII-oocyte extracts have different roles on nuclear reprogramming. Furthermore, both oocyte extracts induced site-specific demethylation in the upstream region of NANOG. These results indicate that cellfree extracts derived from GV- and MII-oocytes could be useful for studying the mechanisms involved in nuclear reprogramming. cell-free extract, cell-free system, dedifferentiation, DNA methylation, extracts, gene regulation, histone acetylation, NANOG, oocyte, pig, reprogramming
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reprogramming events of mammalian Somatic Cells induced by xenopus laevis egg extracts
Molecular Reproduction and Development, 2007Co-Authors: Kei Miyamoto, Naojiro Minami, Masayasu Yamada, Mari Ohnuki, Keita Ohsumi, Tadashi Furusawa, Sandeep Goel, Tomoyuki Tokunaga, Hiroshi ImaiAbstract:It is known that differentiated Cells can be reprogrammed to an undifferentiated state in oocyte cytoplasm after nuclear transfer. Recently, some reports suggested that Xenopus egg extracts have the ability to reprogram mammalian Somatic Cells. Reprogramming events of mammalian Cells after Xenopus egg extract treatment and after cell culture of extract-treated Cells have not been elucidated. In this experiment, we examined reprogramming events in reversibly permeabilized or nonpermeabilized porcine fibroblast Cells after Xenopus egg extract treatment. The Xenopus egg-specific histone B4 was assembled on porcine chromatin and nuclear lamin LIII was incorporated into nuclei. Deacetylation of histone H3 at lysine 9 in extract-treated Cells was detected in nonpermeabilized Cells, suggesting that a part of reprogramming may be induced even in nonpermeabilized Cells. Following culture of extract-treated Cells, the Cells began to express the pluripotent marker genes such as POU5F1 (OCT4) and SOX2 and to form colonies. Reactivation of the OCT4 gene in extract-treated Cells was also confirmed in bovine fibroblasts transformed with an OCT4-EGFP construct. These results suggest that nuclei of mammalian Cells can be partially reprogrammed to an embryonic state by Xenopus egg extracts and the remodeled Cells partly dedifferentiate after cell culture. A system using egg extracts may be useful for understanding the mechanisms and processes of dedifferentiation and reprogramming of mammalian Somatic Cells after nuclear transfer. Mol. Reprod. Dev. 74: 1268–1277, 2007. © 2007 Wiley-Liss, Inc.
Masayasu Yamada - One of the best experts on this subject based on the ideXlab platform.
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cell free extracts from mammalian oocytes partially induce nuclear reprogramming in Somatic Cells
Biology of Reproduction, 2009Co-Authors: Kei Miyamoto, Tomoyuki Tsukiyama, Naojiro Minami, Masayasu Yamada, Ning Li, Hiroshi ImaiAbstract:Nuclear transfer has been regarded as the only reliable tool for studying nuclear reprogramming of mammalian Somatic Cells by oocytes. However, nuclear transfer is not well suited for biochemical analyses of the molecular mechanisms of reprogramming. A cell-free system from oocytes is an attractive alternative way to mimic reprogramming in vitro, since a large number of Cells can be treated and analyzed. Nevertheless, a cell-free system using oocytes has not been developed in mammals. Here, cell extracts from porcine oocytes were prepared and their ability to induce nuclear reprogramming was evaluated. Extracts from metaphase II (MII) oocytes erased the machinery for regulating gene expression in reversibly permeabilized Somatic Cells. For example, the extracts caused histone deacetylation and the disappearance of TATA boxbinding protein from the nuclei. However, MII-extract-treated Cells did not show any obvious changes after cell culture. In contrast, extracts from germinal vesicle (GV) oocytes activated pluripotent marker genes, especially NANOG, and induced partial dedifferentiation after cell culture. The activation of pluripotent marker genes by GV extracts was associated with histone acetylation that was induced during extract treatment. These results indicate that GV- and MII-oocyte extracts have different roles on nuclear reprogramming. Furthermore, both oocyte extracts induced site-specific demethylation in the upstream region of NANOG. These results indicate that cellfree extracts derived from GV- and MII-oocytes could be useful for studying the mechanisms involved in nuclear reprogramming. cell-free extract, cell-free system, dedifferentiation, DNA methylation, extracts, gene regulation, histone acetylation, NANOG, oocyte, pig, reprogramming
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cell free extracts from mammalian oocytes partially induce nuclear reprogramming in Somatic Cells
Biology of Reproduction, 2009Co-Authors: Kei Miyamoto, Tomoyuki Tsukiyama, Naojiro Minami, Masayasu Yamada, Ning Li, Yang Yang, Hiroshi ImaiAbstract:Nuclear transfer has been regarded as the only reliable tool for studying nuclear reprogramming of mammalian Somatic Cells by oocytes. However, nuclear transfer is not well suited for biochemical analyses of the molecular mechanisms of reprogramming. A cell-free system from oocytes is an attractive alternative way to mimic reprogramming in vitro, since a large number of Cells can be treated and analyzed. Nevertheless, a cell-free system using oocytes has not been developed in mammals. Here, cell extracts from porcine oocytes were prepared and their ability to induce nuclear reprogramming was evaluated. Extracts from metaphase II (MII) oocytes erased the machinery for regulating gene expression in reversibly permeabilized Somatic Cells. For example, the extracts caused histone deacetylation and the disappearance of TATA boxbinding protein from the nuclei. However, MII-extract-treated Cells did not show any obvious changes after cell culture. In contrast, extracts from germinal vesicle (GV) oocytes activated pluripotent marker genes, especially NANOG, and induced partial dedifferentiation after cell culture. The activation of pluripotent marker genes by GV extracts was associated with histone acetylation that was induced during extract treatment. These results indicate that GV- and MII-oocyte extracts have different roles on nuclear reprogramming. Furthermore, both oocyte extracts induced site-specific demethylation in the upstream region of NANOG. These results indicate that cellfree extracts derived from GV- and MII-oocytes could be useful for studying the mechanisms involved in nuclear reprogramming. cell-free extract, cell-free system, dedifferentiation, DNA methylation, extracts, gene regulation, histone acetylation, NANOG, oocyte, pig, reprogramming
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reprogramming events of mammalian Somatic Cells induced by xenopus laevis egg extracts
Molecular Reproduction and Development, 2007Co-Authors: Kei Miyamoto, Naojiro Minami, Masayasu Yamada, Mari Ohnuki, Keita Ohsumi, Tadashi Furusawa, Sandeep Goel, Tomoyuki Tokunaga, Hiroshi ImaiAbstract:It is known that differentiated Cells can be reprogrammed to an undifferentiated state in oocyte cytoplasm after nuclear transfer. Recently, some reports suggested that Xenopus egg extracts have the ability to reprogram mammalian Somatic Cells. Reprogramming events of mammalian Cells after Xenopus egg extract treatment and after cell culture of extract-treated Cells have not been elucidated. In this experiment, we examined reprogramming events in reversibly permeabilized or nonpermeabilized porcine fibroblast Cells after Xenopus egg extract treatment. The Xenopus egg-specific histone B4 was assembled on porcine chromatin and nuclear lamin LIII was incorporated into nuclei. Deacetylation of histone H3 at lysine 9 in extract-treated Cells was detected in nonpermeabilized Cells, suggesting that a part of reprogramming may be induced even in nonpermeabilized Cells. Following culture of extract-treated Cells, the Cells began to express the pluripotent marker genes such as POU5F1 (OCT4) and SOX2 and to form colonies. Reactivation of the OCT4 gene in extract-treated Cells was also confirmed in bovine fibroblasts transformed with an OCT4-EGFP construct. These results suggest that nuclei of mammalian Cells can be partially reprogrammed to an embryonic state by Xenopus egg extracts and the remodeled Cells partly dedifferentiate after cell culture. A system using egg extracts may be useful for understanding the mechanisms and processes of dedifferentiation and reprogramming of mammalian Somatic Cells after nuclear transfer. Mol. Reprod. Dev. 74: 1268–1277, 2007. © 2007 Wiley-Liss, Inc.
Naojiro Minami - One of the best experts on this subject based on the ideXlab platform.
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cell free extracts from mammalian oocytes partially induce nuclear reprogramming in Somatic Cells
Biology of Reproduction, 2009Co-Authors: Kei Miyamoto, Tomoyuki Tsukiyama, Naojiro Minami, Masayasu Yamada, Ning Li, Hiroshi ImaiAbstract:Nuclear transfer has been regarded as the only reliable tool for studying nuclear reprogramming of mammalian Somatic Cells by oocytes. However, nuclear transfer is not well suited for biochemical analyses of the molecular mechanisms of reprogramming. A cell-free system from oocytes is an attractive alternative way to mimic reprogramming in vitro, since a large number of Cells can be treated and analyzed. Nevertheless, a cell-free system using oocytes has not been developed in mammals. Here, cell extracts from porcine oocytes were prepared and their ability to induce nuclear reprogramming was evaluated. Extracts from metaphase II (MII) oocytes erased the machinery for regulating gene expression in reversibly permeabilized Somatic Cells. For example, the extracts caused histone deacetylation and the disappearance of TATA boxbinding protein from the nuclei. However, MII-extract-treated Cells did not show any obvious changes after cell culture. In contrast, extracts from germinal vesicle (GV) oocytes activated pluripotent marker genes, especially NANOG, and induced partial dedifferentiation after cell culture. The activation of pluripotent marker genes by GV extracts was associated with histone acetylation that was induced during extract treatment. These results indicate that GV- and MII-oocyte extracts have different roles on nuclear reprogramming. Furthermore, both oocyte extracts induced site-specific demethylation in the upstream region of NANOG. These results indicate that cellfree extracts derived from GV- and MII-oocytes could be useful for studying the mechanisms involved in nuclear reprogramming. cell-free extract, cell-free system, dedifferentiation, DNA methylation, extracts, gene regulation, histone acetylation, NANOG, oocyte, pig, reprogramming
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cell free extracts from mammalian oocytes partially induce nuclear reprogramming in Somatic Cells
Biology of Reproduction, 2009Co-Authors: Kei Miyamoto, Tomoyuki Tsukiyama, Naojiro Minami, Masayasu Yamada, Ning Li, Yang Yang, Hiroshi ImaiAbstract:Nuclear transfer has been regarded as the only reliable tool for studying nuclear reprogramming of mammalian Somatic Cells by oocytes. However, nuclear transfer is not well suited for biochemical analyses of the molecular mechanisms of reprogramming. A cell-free system from oocytes is an attractive alternative way to mimic reprogramming in vitro, since a large number of Cells can be treated and analyzed. Nevertheless, a cell-free system using oocytes has not been developed in mammals. Here, cell extracts from porcine oocytes were prepared and their ability to induce nuclear reprogramming was evaluated. Extracts from metaphase II (MII) oocytes erased the machinery for regulating gene expression in reversibly permeabilized Somatic Cells. For example, the extracts caused histone deacetylation and the disappearance of TATA boxbinding protein from the nuclei. However, MII-extract-treated Cells did not show any obvious changes after cell culture. In contrast, extracts from germinal vesicle (GV) oocytes activated pluripotent marker genes, especially NANOG, and induced partial dedifferentiation after cell culture. The activation of pluripotent marker genes by GV extracts was associated with histone acetylation that was induced during extract treatment. These results indicate that GV- and MII-oocyte extracts have different roles on nuclear reprogramming. Furthermore, both oocyte extracts induced site-specific demethylation in the upstream region of NANOG. These results indicate that cellfree extracts derived from GV- and MII-oocytes could be useful for studying the mechanisms involved in nuclear reprogramming. cell-free extract, cell-free system, dedifferentiation, DNA methylation, extracts, gene regulation, histone acetylation, NANOG, oocyte, pig, reprogramming
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reprogramming events of mammalian Somatic Cells induced by xenopus laevis egg extracts
Molecular Reproduction and Development, 2007Co-Authors: Kei Miyamoto, Naojiro Minami, Masayasu Yamada, Mari Ohnuki, Keita Ohsumi, Tadashi Furusawa, Sandeep Goel, Tomoyuki Tokunaga, Hiroshi ImaiAbstract:It is known that differentiated Cells can be reprogrammed to an undifferentiated state in oocyte cytoplasm after nuclear transfer. Recently, some reports suggested that Xenopus egg extracts have the ability to reprogram mammalian Somatic Cells. Reprogramming events of mammalian Cells after Xenopus egg extract treatment and after cell culture of extract-treated Cells have not been elucidated. In this experiment, we examined reprogramming events in reversibly permeabilized or nonpermeabilized porcine fibroblast Cells after Xenopus egg extract treatment. The Xenopus egg-specific histone B4 was assembled on porcine chromatin and nuclear lamin LIII was incorporated into nuclei. Deacetylation of histone H3 at lysine 9 in extract-treated Cells was detected in nonpermeabilized Cells, suggesting that a part of reprogramming may be induced even in nonpermeabilized Cells. Following culture of extract-treated Cells, the Cells began to express the pluripotent marker genes such as POU5F1 (OCT4) and SOX2 and to form colonies. Reactivation of the OCT4 gene in extract-treated Cells was also confirmed in bovine fibroblasts transformed with an OCT4-EGFP construct. These results suggest that nuclei of mammalian Cells can be partially reprogrammed to an embryonic state by Xenopus egg extracts and the remodeled Cells partly dedifferentiate after cell culture. A system using egg extracts may be useful for understanding the mechanisms and processes of dedifferentiation and reprogramming of mammalian Somatic Cells after nuclear transfer. Mol. Reprod. Dev. 74: 1268–1277, 2007. © 2007 Wiley-Liss, Inc.
Teruhiko Wakayama - One of the best experts on this subject based on the ideXlab platform.
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retraction stimulus triggered fate conversion of Somatic Cells into pluripotency
Nature, 2014Co-Authors: Haruko Obokata, Teruhiko Wakayama, Yoshiki Sasai, Koji Kojima, Martin P Vacanti, Hitoshi Niwa, Masayuki Yamato, Charles A VacantiAbstract:Here we report a unique cellular reprogramming phenomenon, called stimulus-triggered acquisition of pluripotency (STAP), which requires neither nuclear transfer nor the introduction of transcription factors. In STAP, strong external stimuli such as a transient low-pH stressor reprogrammed mammalian Somatic Cells, resulting in the generation of pluripotent Cells. Through real-time imaging of STAP Cells derived from purified lymphocytes, as well as gene rearrangement analysis, we found that committed Somatic Cells give rise to STAP Cells by reprogramming rather than selection. STAP Cells showed a substantial decrease in DNA methylation in the regulatory regions of pluripotency marker genes. Blastocyst injection showed that STAP Cells efficiently contribute to chimaeric embryos and to offspring via germline transmission. We also demonstrate the derivation of robustly expandable pluripotent cell lines from STAP Cells. Thus, our findings indicate that epigenetic fate determination of mammalian Cells can be markedly converted in a context-dependent manner by strong environmental cues. One of two papers describing a reprogramming phenomenon called stimulus-triggered acquisition of pluripotency (STAP) — in STAP, lineage-committed adult Somatic Cells are reprogrammed to pluripotency by transient exposure to low-pH treatment, and extensive analysis of the molecular features and developmental potential of STAP Cells indicates that they represent a unique state of pluripotency. The fates of the Somatic Cells that form the bulk of the mammalian body are thought to be largely determined by the time the cellular differentiation processes of development have been completed. Reprogramming in response to environmental stress has been observed in plants but not so far in mammalian Cells. Now two manuscripts by Haruko Obokata and colleagues describe an unexpected reprogramming phenomenon, which the authors call stimulus-triggered acquisition of pluripotency (STAP). In STAP, mouse Somatic Cells such as CD45+ haematopoietic Cells are reprogrammed to pluripotency by transient exposure to low pH. Extensive analysis of the molecular features and developmental potential of STAP Cells suggests that they represent a unique state of pluripotency — and provide an alternative source of pluripotent Cells to the use of transcription factors, as has become routine for induced pluripotent stem cell production.
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stimulus triggered fate conversion of Somatic Cells into pluripotency
Nature, 2014Co-Authors: Haruko Obokata, Teruhiko Wakayama, Yoshiki Sasai, Koji Kojima, Martin P Vacanti, Hitoshi Niwa, Masayuki Yamato, Charles A VacantiAbstract:The fates of the Somatic Cells that form the bulk of the mammalian body are thought to be largely determined by the time the cellular differentiation processes of development have been completed. Reprogramming in response to environmental stress has been observed in plants but not so far in mammalian Cells. Now two manuscripts by Haruko Obokata and colleagues describe an unexpected reprogramming phenomenon, which the authors call stimulus-triggered acquisition of pluripotency (STAP). In STAP, mouse Somatic Cells such as CD45+ haematopoietic Cells are reprogrammed to pluripotency by transient exposure to low pH. Extensive analysis of the molecular features and developmental potential of STAP Cells suggests that they represent a unique state of pluripotency and provide an alternative source of pluripotent Cells to the use of transcription factors, as has become routine for induced pluripotent stem cell production.
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production of cloned mice and es Cells from adult Somatic Cells by nuclear transfer how to improve cloning efficiency
Journal of Reproduction and Development, 2007Co-Authors: Teruhiko WakayamaAbstract:Although it has now been 10 years since the first cloned mammals were generated from Somatic Cells using nuclear transfer (NT), most cloned embryos usually undergo developmental arrest prior to or soon after implantation, and the success rate for producing live offspring by cloning remains below 5%. The low success rate is believed to be associated with epigenetic errors, including abnormal DNA hypermethylation, but the mechanism of "reprogramming" is unclear. We have been able to develop a stable NT method in the mouse in which donor nuclei are directly injected into the oocyte using a piezo-actuated micromanipulator. Especially in the mouse, only a few laboratories can make clones from adult Somatic Cells, and cloned mice are never successfully produced from most mouse strains. However, this technique promises to be an important tool for future research in basic biology. For example, NT can be used to generate embryonic stem (NT-ES) cell lines from a patient's own Somatic Cells. We have shown that NT-ES Cells are equivalent to ES Cells derived from fertilized embryos and that they can be generated relatively easily from a variety of mouse genotypes and cell types of both sexes, even though it may be more difficult to generate clones directly. In general, NT-ES cell techniques are expected to be applied to regenerative medicine; however, this technique can also be applied to the preservation of genetic resources of mouse strain instead of embryos, oocytes and spermatozoa. This review describes how to improve cloning efficiency and NT-ES cell establishment and further applications.
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differentiation of embryonic stem cell lines generated from adult Somatic Cells by nuclear transfer
Science, 2001Co-Authors: Teruhiko Wakayama, Viviane Tabar, Ivan Rodriguez, Anthony C F Perry, Lorenz Studer, Peter T MombaertsAbstract:Embryonic stem (ES) Cells are fully pluripotent in that they can differentiate into all cell types, including gametes. We have derived 35 ES cell lines via nuclear transfer (ntES cell lines) from adult mouse Somatic Cells of inbred, hybrid, and mutant strains. ntES Cells contributed to an extensive variety of cell types, including dopaminergic and serotonergic neurons in vitro and germ Cells in vivo. Cloning by transfer of ntES cell nuclei could result in normal development of fertile adults. These studies demonstrate the full pluripotency of ntES Cells.
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differentiation of embryonic stem cell lines generated from adult Somatic Cells by nuclear transfer
Science, 2001Co-Authors: Teruhiko Wakayama, Viviane Tabar, Ivan Rodriguez, Anthony C F Perry, Lorenz Studer, Peter T MombaertsAbstract:Embryonic stem (ES) Cells are fully pluripotent in that they can differentiate into all cell types, including gametes. We have derived 35 ES cell lines via nuclear transfer (ntES cell lines) from adult mouse Somatic Cells of inbred, hybrid, and mutant strains. ntES Cells contributed to an extensive variety of cell types, including dopaminergic and serotonergic neurons in vitro and germ Cells in vivo. Cloning by transfer of ntES cell nuclei could result in normal development of fertile adults. These studies demonstrate the full pluripotency of ntES Cells.
