The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Toru Nakano - One of the best experts on this subject based on the ideXlab platform.
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Stella controls chromocenter formation through regulation of Daxx expression in 2-cell embryos.
Biochemical and biophysical research communications, 2015Co-Authors: Tatsuhiko Arakawa, Tsunetoshi Nakatani, Tohru Kimura, Masaaki Oda, Yoichi Sekita, Toshinobu Nakamura, Yasuyoshi Kimura, Toru NakanoAbstract:In mammals, the structure of the pericentromeric region alters from a ring structure to a dot-like structure during the 2-cell stage. This structural alteration is termed chromocenter formation (CF) and is required for preimplantation development. Although reverse transcripts of major satellite repeats at pericentromeric regions are known to play roles in CF, its underlying mechanism is not fully understood. We previously reported that Stella (also known as PGC7 and Dppa3) deficiency led to developmental arrest at the preimplantation stage, accompanied by frequent chromosome segregation. In this study, we further investigated the effect of Stella deficiency on chromatin reorganization. The Stella-null embryos exhibited impaired CF and reduced expression of the reverse strand of major satellite repeats. In addition, the accumulation of H3.3, a histone H3 variant associated with transcriptional activation, at the pericentromeric regions and expression of the H3.3-specific chaperone Daxx were reduced in Stella-null embryos. These abnormalities were restored by the enforced expression of Daxx in Stella-null embryos. Thus, Stella controls the expression of Daxx and ensures chromatin reorganization in early embryos.
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Stella preserves maternal chromosome integrity by inhibiting 5hmc induced γh2ax accumulation
EMBO Reports, 2015Co-Authors: Tsunetoshi Nakatani, Kazuo Yamagata, Tohru Kimura, Masaaki Oda, Hiroyuki Nakashima, Mayuko Hori, Yoichi Sekita, Tatsuhiko Arakawa, Toshinobu Nakamura, Toru NakanoAbstract:In the mouse zygote, Stella/PGC7 protects 5-methylcytosine (5mC) of the maternal genome from Tet3-mediated oxidation to 5-hydroxymethylcytosine (5hmC). Although ablation of Stella causes early embryonic lethality, the underlying molecular mechanisms remain unknown. In this study, we report impaired DNA replication and abnormal chromosome segregation (ACS) of maternal chromosomes in Stella-null embryos. In addition, phosphorylation of H2AX (γH2AX), which has been reported to inhibit DNA replication, accumulates in the maternal chromatin of Stella-null zygotes in a Tet3-dependent manner. Cell culture assays verified that ectopic appearance of 5hmC induces abnormal accumulation of γH2AX and subsequent growth retardation. Thus, Stella protects maternal chromosomes from aberrant epigenetic modifications to ensure early embryogenesis.
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Stella preserves maternal chromosome integrity by inhibiting 5hmC‐induced γH2AX accumulation
EMBO reports, 2015Co-Authors: Tsunetoshi Nakatani, Kazuo Yamagata, Tohru Kimura, Masaaki Oda, Hiroyuki Nakashima, Mayuko Hori, Yoichi Sekita, Tatsuhiko Arakawa, Toshinobu Nakamura, Toru NakanoAbstract:In the mouse zygote, Stella/PGC7 protects 5-methylcytosine (5mC) of the maternal genome from Tet3-mediated oxidation to 5-hydroxymethylcytosine (5hmC). Although ablation of Stella causes early embryonic lethality, the underlying molecular mechanisms remain unknown. In this study, we report impaired DNA replication and abnormal chromosome segregation (ACS) of maternal chromosomes in Stella-null embryos. In addition, phosphorylation of H2AX (γH2AX), which has been reported to inhibit DNA replication, accumulates in the maternal chromatin of Stella-null zygotes in a Tet3-dependent manner. Cell culture assays verified that ectopic appearance of 5hmC induces abnormal accumulation of γH2AX and subsequent growth retardation. Thus, Stella protects maternal chromosomes from aberrant epigenetic modifications to ensure early embryogenesis.
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Stella is a maternal effect gene required for normal early development in mice.
Current biology : CB, 2003Co-Authors: Bernhard Payer, Mitinori Saitou, Sheila C. Barton, Rosemary R. Thresher, John Dixon, Dirk Zahn, William H. Colledge, Mark B.l. Carlton, Toru Nakano, M. Azim SuraniAbstract:Abstract Stella is a novel gene specifically expressed in primordial germ cells, oocytes, preimplantation embryos, and pluripotent cells [1, 2]. It encodes a protein with a SAP-like domain [3] and a splicing factor motif-like structure, suggesting possible roles in chromosomal organization or RNA processing. Here, we have investigated the effects of a targeted mutation of Stella in mice. We show that while matings between heterozygous animals resulted in the birth of apparently normal Stella null offspring, Stella -deficient females displayed severely reduced fertility due to a lack of maternally inherited Stella-protein in their oocytes. Indeed, we demonstrate that embryos without Stella are compromised in preimplantation development and rarely reach the blastocyst stage. Stella is thus one of few known mammalian maternal effect genes [4–9], as the phenotypic effect on embryonic development is mainly a consequence of the maternal Stella mutant genotype. Furthermore, we show that Stella that is expressed in human oocytes [10] is also expressed in human pluripotent cells and in germ cell tumors. Interestingly, human chromosome 12p, which harbours Stella , is consistently overrepresented in these tumors [11]. These findings suggest a similar role for Stella during early human development as in mice and a potential involvement in germ cell tumors.
Toshinobu Nakamura - One of the best experts on this subject based on the ideXlab platform.
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Stella controls chromocenter formation through regulation of Daxx expression in 2-cell embryos.
Biochemical and biophysical research communications, 2015Co-Authors: Tatsuhiko Arakawa, Tsunetoshi Nakatani, Tohru Kimura, Masaaki Oda, Yoichi Sekita, Toshinobu Nakamura, Yasuyoshi Kimura, Toru NakanoAbstract:In mammals, the structure of the pericentromeric region alters from a ring structure to a dot-like structure during the 2-cell stage. This structural alteration is termed chromocenter formation (CF) and is required for preimplantation development. Although reverse transcripts of major satellite repeats at pericentromeric regions are known to play roles in CF, its underlying mechanism is not fully understood. We previously reported that Stella (also known as PGC7 and Dppa3) deficiency led to developmental arrest at the preimplantation stage, accompanied by frequent chromosome segregation. In this study, we further investigated the effect of Stella deficiency on chromatin reorganization. The Stella-null embryos exhibited impaired CF and reduced expression of the reverse strand of major satellite repeats. In addition, the accumulation of H3.3, a histone H3 variant associated with transcriptional activation, at the pericentromeric regions and expression of the H3.3-specific chaperone Daxx were reduced in Stella-null embryos. These abnormalities were restored by the enforced expression of Daxx in Stella-null embryos. Thus, Stella controls the expression of Daxx and ensures chromatin reorganization in early embryos.
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Stella preserves maternal chromosome integrity by inhibiting 5hmc induced γh2ax accumulation
EMBO Reports, 2015Co-Authors: Tsunetoshi Nakatani, Kazuo Yamagata, Tohru Kimura, Masaaki Oda, Hiroyuki Nakashima, Mayuko Hori, Yoichi Sekita, Tatsuhiko Arakawa, Toshinobu Nakamura, Toru NakanoAbstract:In the mouse zygote, Stella/PGC7 protects 5-methylcytosine (5mC) of the maternal genome from Tet3-mediated oxidation to 5-hydroxymethylcytosine (5hmC). Although ablation of Stella causes early embryonic lethality, the underlying molecular mechanisms remain unknown. In this study, we report impaired DNA replication and abnormal chromosome segregation (ACS) of maternal chromosomes in Stella-null embryos. In addition, phosphorylation of H2AX (γH2AX), which has been reported to inhibit DNA replication, accumulates in the maternal chromatin of Stella-null zygotes in a Tet3-dependent manner. Cell culture assays verified that ectopic appearance of 5hmC induces abnormal accumulation of γH2AX and subsequent growth retardation. Thus, Stella protects maternal chromosomes from aberrant epigenetic modifications to ensure early embryogenesis.
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Stella preserves maternal chromosome integrity by inhibiting 5hmC‐induced γH2AX accumulation
EMBO reports, 2015Co-Authors: Tsunetoshi Nakatani, Kazuo Yamagata, Tohru Kimura, Masaaki Oda, Hiroyuki Nakashima, Mayuko Hori, Yoichi Sekita, Tatsuhiko Arakawa, Toshinobu Nakamura, Toru NakanoAbstract:In the mouse zygote, Stella/PGC7 protects 5-methylcytosine (5mC) of the maternal genome from Tet3-mediated oxidation to 5-hydroxymethylcytosine (5hmC). Although ablation of Stella causes early embryonic lethality, the underlying molecular mechanisms remain unknown. In this study, we report impaired DNA replication and abnormal chromosome segregation (ACS) of maternal chromosomes in Stella-null embryos. In addition, phosphorylation of H2AX (γH2AX), which has been reported to inhibit DNA replication, accumulates in the maternal chromatin of Stella-null zygotes in a Tet3-dependent manner. Cell culture assays verified that ectopic appearance of 5hmC induces abnormal accumulation of γH2AX and subsequent growth retardation. Thus, Stella protects maternal chromosomes from aberrant epigenetic modifications to ensure early embryogenesis.
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pgc7 Stella protects against dna demethylation in early embryogenesis
Nature Cell Biology, 2007Co-Authors: Toshinobu Nakamura, Tohru Kimura, Yoshikazu Arai, Hiroki Umehara, Masaaki Masuhara, Hisaaki Taniguchi, Toshihiro Sekimoto, Masahito Ikawa, Yoshihiro Yoneda, Masaru OkabeAbstract:DNA methylation is an important means of epigenetic gene regulation1,2 and must be carefully controlled as a prerequisite for normal early embryogenesis. Although global demethylation occurs soon after fertilization, it is not evenly distributed throughout the genome. Genomic imprinting and epigenetic asymmetry between parental genomes, that is, delayed demethylation of the maternal genome after fertilization3,4,5,6, are clear examples of the functional importance of DNA methylation. Here, we show that PGC7/Stella, a maternal factor essential for early development, protects the DNA methylation state of several imprinted loci and epigenetic asymmetry. After determining that PGC7/Stella binds to Ran binding protein 5 (RanBP5; a nuclear transport shuttle protein), mutant versions of the two proteins were used to examine exactly when and where PGC7/Stella functions within the cell. It is likely that PGC7/Stella protects the maternal genome from demethylation only after localizing to the nucleus, where it maintains the methylation of several imprinted genes. These results demonstrate that PGC7/Stella is indispensable for the maintenance of methylation involved in epigenetic reprogramming after fertilization.
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PGC7/Stella protects against DNA demethylation in early embryogenesis.
Nature cell biology, 2006Co-Authors: Toshinobu Nakamura, Tohru Kimura, Yoshikazu Arai, Hiroki Umehara, Masaaki Masuhara, Hisaaki Taniguchi, Toshihiro Sekimoto, Masahito Ikawa, Yoshihiro Yoneda, Masaru OkabeAbstract:DNA methylation is an important means of epigenetic gene regulation and must be carefully controlled as a prerequisite for normal early embryogenesis. Although global demethylation occurs soon after fertilization, it is not evenly distributed throughout the genome. Genomic imprinting and epigenetic asymmetry between parental genomes, that is, delayed demethylation of the maternal genome after fertilization, are clear examples of the functional importance of DNA methylation. Here, we show that PGC7/Stella, a maternal factor essential for early development, protects the DNA methylation state of several imprinted loci and epigenetic asymmetry. After determining that PGC7/Stella binds to Ran binding protein 5 (RanBP5; a nuclear transport shuttle protein), mutant versions of the two proteins were used to examine exactly when and where PGC7/Stella functions within the cell. It is likely that PGC7/Stella protects the maternal genome from demethylation only after localizing to the nucleus, where it maintains the methylation of several imprinted genes. These results demonstrate that PGC7/Stella is indispensable for the maintenance of methylation involved in epigenetic reprogramming after fertilization.
Tohru Kimura - One of the best experts on this subject based on the ideXlab platform.
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Stella controls chromocenter formation through regulation of Daxx expression in 2-cell embryos.
Biochemical and biophysical research communications, 2015Co-Authors: Tatsuhiko Arakawa, Tsunetoshi Nakatani, Tohru Kimura, Masaaki Oda, Yoichi Sekita, Toshinobu Nakamura, Yasuyoshi Kimura, Toru NakanoAbstract:In mammals, the structure of the pericentromeric region alters from a ring structure to a dot-like structure during the 2-cell stage. This structural alteration is termed chromocenter formation (CF) and is required for preimplantation development. Although reverse transcripts of major satellite repeats at pericentromeric regions are known to play roles in CF, its underlying mechanism is not fully understood. We previously reported that Stella (also known as PGC7 and Dppa3) deficiency led to developmental arrest at the preimplantation stage, accompanied by frequent chromosome segregation. In this study, we further investigated the effect of Stella deficiency on chromatin reorganization. The Stella-null embryos exhibited impaired CF and reduced expression of the reverse strand of major satellite repeats. In addition, the accumulation of H3.3, a histone H3 variant associated with transcriptional activation, at the pericentromeric regions and expression of the H3.3-specific chaperone Daxx were reduced in Stella-null embryos. These abnormalities were restored by the enforced expression of Daxx in Stella-null embryos. Thus, Stella controls the expression of Daxx and ensures chromatin reorganization in early embryos.
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Stella preserves maternal chromosome integrity by inhibiting 5hmc induced γh2ax accumulation
EMBO Reports, 2015Co-Authors: Tsunetoshi Nakatani, Kazuo Yamagata, Tohru Kimura, Masaaki Oda, Hiroyuki Nakashima, Mayuko Hori, Yoichi Sekita, Tatsuhiko Arakawa, Toshinobu Nakamura, Toru NakanoAbstract:In the mouse zygote, Stella/PGC7 protects 5-methylcytosine (5mC) of the maternal genome from Tet3-mediated oxidation to 5-hydroxymethylcytosine (5hmC). Although ablation of Stella causes early embryonic lethality, the underlying molecular mechanisms remain unknown. In this study, we report impaired DNA replication and abnormal chromosome segregation (ACS) of maternal chromosomes in Stella-null embryos. In addition, phosphorylation of H2AX (γH2AX), which has been reported to inhibit DNA replication, accumulates in the maternal chromatin of Stella-null zygotes in a Tet3-dependent manner. Cell culture assays verified that ectopic appearance of 5hmC induces abnormal accumulation of γH2AX and subsequent growth retardation. Thus, Stella protects maternal chromosomes from aberrant epigenetic modifications to ensure early embryogenesis.
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Stella preserves maternal chromosome integrity by inhibiting 5hmC‐induced γH2AX accumulation
EMBO reports, 2015Co-Authors: Tsunetoshi Nakatani, Kazuo Yamagata, Tohru Kimura, Masaaki Oda, Hiroyuki Nakashima, Mayuko Hori, Yoichi Sekita, Tatsuhiko Arakawa, Toshinobu Nakamura, Toru NakanoAbstract:In the mouse zygote, Stella/PGC7 protects 5-methylcytosine (5mC) of the maternal genome from Tet3-mediated oxidation to 5-hydroxymethylcytosine (5hmC). Although ablation of Stella causes early embryonic lethality, the underlying molecular mechanisms remain unknown. In this study, we report impaired DNA replication and abnormal chromosome segregation (ACS) of maternal chromosomes in Stella-null embryos. In addition, phosphorylation of H2AX (γH2AX), which has been reported to inhibit DNA replication, accumulates in the maternal chromatin of Stella-null zygotes in a Tet3-dependent manner. Cell culture assays verified that ectopic appearance of 5hmC induces abnormal accumulation of γH2AX and subsequent growth retardation. Thus, Stella protects maternal chromosomes from aberrant epigenetic modifications to ensure early embryogenesis.
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pgc7 Stella protects against dna demethylation in early embryogenesis
Nature Cell Biology, 2007Co-Authors: Toshinobu Nakamura, Tohru Kimura, Yoshikazu Arai, Hiroki Umehara, Masaaki Masuhara, Hisaaki Taniguchi, Toshihiro Sekimoto, Masahito Ikawa, Yoshihiro Yoneda, Masaru OkabeAbstract:DNA methylation is an important means of epigenetic gene regulation1,2 and must be carefully controlled as a prerequisite for normal early embryogenesis. Although global demethylation occurs soon after fertilization, it is not evenly distributed throughout the genome. Genomic imprinting and epigenetic asymmetry between parental genomes, that is, delayed demethylation of the maternal genome after fertilization3,4,5,6, are clear examples of the functional importance of DNA methylation. Here, we show that PGC7/Stella, a maternal factor essential for early development, protects the DNA methylation state of several imprinted loci and epigenetic asymmetry. After determining that PGC7/Stella binds to Ran binding protein 5 (RanBP5; a nuclear transport shuttle protein), mutant versions of the two proteins were used to examine exactly when and where PGC7/Stella functions within the cell. It is likely that PGC7/Stella protects the maternal genome from demethylation only after localizing to the nucleus, where it maintains the methylation of several imprinted genes. These results demonstrate that PGC7/Stella is indispensable for the maintenance of methylation involved in epigenetic reprogramming after fertilization.
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PGC7/Stella protects against DNA demethylation in early embryogenesis.
Nature cell biology, 2006Co-Authors: Toshinobu Nakamura, Tohru Kimura, Yoshikazu Arai, Hiroki Umehara, Masaaki Masuhara, Hisaaki Taniguchi, Toshihiro Sekimoto, Masahito Ikawa, Yoshihiro Yoneda, Masaru OkabeAbstract:DNA methylation is an important means of epigenetic gene regulation and must be carefully controlled as a prerequisite for normal early embryogenesis. Although global demethylation occurs soon after fertilization, it is not evenly distributed throughout the genome. Genomic imprinting and epigenetic asymmetry between parental genomes, that is, delayed demethylation of the maternal genome after fertilization, are clear examples of the functional importance of DNA methylation. Here, we show that PGC7/Stella, a maternal factor essential for early development, protects the DNA methylation state of several imprinted loci and epigenetic asymmetry. After determining that PGC7/Stella binds to Ran binding protein 5 (RanBP5; a nuclear transport shuttle protein), mutant versions of the two proteins were used to examine exactly when and where PGC7/Stella functions within the cell. It is likely that PGC7/Stella protects the maternal genome from demethylation only after localizing to the nucleus, where it maintains the methylation of several imprinted genes. These results demonstrate that PGC7/Stella is indispensable for the maintenance of methylation involved in epigenetic reprogramming after fertilization.
Tsunetoshi Nakatani - One of the best experts on this subject based on the ideXlab platform.
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Stella controls chromocenter formation through regulation of Daxx expression in 2-cell embryos.
Biochemical and biophysical research communications, 2015Co-Authors: Tatsuhiko Arakawa, Tsunetoshi Nakatani, Tohru Kimura, Masaaki Oda, Yoichi Sekita, Toshinobu Nakamura, Yasuyoshi Kimura, Toru NakanoAbstract:In mammals, the structure of the pericentromeric region alters from a ring structure to a dot-like structure during the 2-cell stage. This structural alteration is termed chromocenter formation (CF) and is required for preimplantation development. Although reverse transcripts of major satellite repeats at pericentromeric regions are known to play roles in CF, its underlying mechanism is not fully understood. We previously reported that Stella (also known as PGC7 and Dppa3) deficiency led to developmental arrest at the preimplantation stage, accompanied by frequent chromosome segregation. In this study, we further investigated the effect of Stella deficiency on chromatin reorganization. The Stella-null embryos exhibited impaired CF and reduced expression of the reverse strand of major satellite repeats. In addition, the accumulation of H3.3, a histone H3 variant associated with transcriptional activation, at the pericentromeric regions and expression of the H3.3-specific chaperone Daxx were reduced in Stella-null embryos. These abnormalities were restored by the enforced expression of Daxx in Stella-null embryos. Thus, Stella controls the expression of Daxx and ensures chromatin reorganization in early embryos.
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Stella preserves maternal chromosome integrity by inhibiting 5hmc induced γh2ax accumulation
EMBO Reports, 2015Co-Authors: Tsunetoshi Nakatani, Kazuo Yamagata, Tohru Kimura, Masaaki Oda, Hiroyuki Nakashima, Mayuko Hori, Yoichi Sekita, Tatsuhiko Arakawa, Toshinobu Nakamura, Toru NakanoAbstract:In the mouse zygote, Stella/PGC7 protects 5-methylcytosine (5mC) of the maternal genome from Tet3-mediated oxidation to 5-hydroxymethylcytosine (5hmC). Although ablation of Stella causes early embryonic lethality, the underlying molecular mechanisms remain unknown. In this study, we report impaired DNA replication and abnormal chromosome segregation (ACS) of maternal chromosomes in Stella-null embryos. In addition, phosphorylation of H2AX (γH2AX), which has been reported to inhibit DNA replication, accumulates in the maternal chromatin of Stella-null zygotes in a Tet3-dependent manner. Cell culture assays verified that ectopic appearance of 5hmC induces abnormal accumulation of γH2AX and subsequent growth retardation. Thus, Stella protects maternal chromosomes from aberrant epigenetic modifications to ensure early embryogenesis.
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Stella preserves maternal chromosome integrity by inhibiting 5hmC‐induced γH2AX accumulation
EMBO reports, 2015Co-Authors: Tsunetoshi Nakatani, Kazuo Yamagata, Tohru Kimura, Masaaki Oda, Hiroyuki Nakashima, Mayuko Hori, Yoichi Sekita, Tatsuhiko Arakawa, Toshinobu Nakamura, Toru NakanoAbstract:In the mouse zygote, Stella/PGC7 protects 5-methylcytosine (5mC) of the maternal genome from Tet3-mediated oxidation to 5-hydroxymethylcytosine (5hmC). Although ablation of Stella causes early embryonic lethality, the underlying molecular mechanisms remain unknown. In this study, we report impaired DNA replication and abnormal chromosome segregation (ACS) of maternal chromosomes in Stella-null embryos. In addition, phosphorylation of H2AX (γH2AX), which has been reported to inhibit DNA replication, accumulates in the maternal chromatin of Stella-null zygotes in a Tet3-dependent manner. Cell culture assays verified that ectopic appearance of 5hmC induces abnormal accumulation of γH2AX and subsequent growth retardation. Thus, Stella protects maternal chromosomes from aberrant epigenetic modifications to ensure early embryogenesis.
Hui Liu - One of the best experts on this subject based on the ideXlab platform.
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Stella cre mice are highly efficient cre deleters
Genesis, 2011Co-Authors: Hui Liu, Wei Wang, Su Kit Chew, Song Choon Lee, George S. Vassiliou, Tony Green, Allan Bradley, Andrew P Futreal, Shujun ZhangAbstract:Cre-loxP recombination is widely used for genetic manipulation of the mouse genome. Here, we report generation and characterization of a new Cre line, Stella-Cre, where Cre expression cassette was targeted to the 3' UTR of the Stella locus. Stella is specifically expressed in preimplantation embryos and in the germline. Cre-loxP recombination efficiency in Stella-Cre mice was investigated at several genomic loci including Rosa26, Jak2, and Npm1. At all the loci examined, we observed 100% Cre-loxP recombination efficiency in the embryos and in the germline. Thus, Stella-Cre mice serve as a very efficient deleter line.
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Stella‐Cre mice are highly efficient Cre deleters
Genesis (New York N.Y. : 2000), 2011Co-Authors: Hui Liu, Wei Wang, Su Kit Chew, Song Choon Lee, George S. Vassiliou, Tony Green, P. Andrew Futreal, Allan Bradley, Shujun ZhangAbstract:Cre-loxP recombination is widely used for genetic manipulation of the mouse genome. Here, we report generation and characterization of a new Cre line, Stella-Cre, where Cre expression cassette was targeted to the 3' UTR of the Stella locus. Stella is specifically expressed in preimplantation embryos and in the germline. Cre-loxP recombination efficiency in Stella-Cre mice was investigated at several genomic loci including Rosa26, Jak2, and Npm1. At all the loci examined, we observed 100% Cre-loxP recombination efficiency in the embryos and in the germline. Thus, Stella-Cre mice serve as a very efficient deleter line.
