Project description:Differentiated somatic cells can be reprogrammed into induced pluripotent stem (iPS) cells by forced expression of four transcription factors—Oct4, Sox2, Klf4, and c-Myc. However, it remains undetermined whether the reprogrammed iPS cells are fully pluripotent, resembling normal embryonic stem (ES) cells, given that no iPS cell lines have been shown to possess the capability to autonomously generate full-term mice after injection into tetraploid blastocysts. Here, we provide evidence demonstrating that iPS cells induced by the four transcription factors can be fully pluripotent and that full-term mice can be produced from complemented tetraploid blastocysts. This work serves as a proof of principle that iPS cells can generate full term embryos by tetraploid complementation.
Project description:Differentiated somatic cells can be reprogrammed into induced pluripotent stem (iPS) cells by forced expression of four transcription factorsâOct4, Sox2, Klf4, and c-Myc. However, it remains undetermined whether the reprogrammed iPS cells are fully pluripotent, resembling normal embryonic stem (ES) cells, given that no iPS cell lines have been shown to possess the capability to autonomously generate full-term mice after injection into tetraploid blastocysts. Here, we provide evidence demonstrating that iPS cells induced by the four transcription factors can be fully pluripotent and that full-term mice can be produced from complemented tetraploid blastocysts. This work serves as a proof of principle that iPS cells can generate full term embryos by tetraploid complementation. We compared the gene expression profile of iPS cell, ES cell and MEF. ES cell and MEF served as control for iPS cell. Three biological repeats were included for each line.
Project description:Differentiated cell can be reprogrammed into totipotent embryo through somatic cell nuclear transfer (SCNT). However, this process is highly inefficient and most cloned embryos arrest at certain developmental stages. Through single cell sequencing combined with embryo biopsy, here we generate a global map of DNA methylome and RNA transcriptome for SCNT embryos with distinct developmental fates. We subsequently demonstrate that the unfaithful reactivation of two histone demethylases, Kdm4b and Kdm5b, accounts for the arrest of cloned embryos at 2-cell and 4-cell stage, respectively. Ectopic expression of Kdm4b and Kdm5b in SCNT can remove H3K9me3 barrier, restore the transcription profile and facilitate the blastocyst developmental efficiency over 95%. Moreover, these cloned embryos can further support full-term development and the derivation of SCNT-embryonic stem cells with greater efficiency. Our study reveals that histone methylation reset is crucial for the development of SCNT embryos, which provides a clue to further improve therapeutic cloning. Examination of histone H3K9me3 modifications in 2-cell embryos and cumulus cells.
Project description:Separation of cell lineages during early mammalian development is required to establish the pluripotent founder cell population that will give rise to the embryo proper and a functional trophoblast to support its development. We systemically assessed the role of the homeobox gene Cdx2 in vivo and in vitro development with an RNAi approach. Effective elimination of both maternal and zygotic Cdx2 resulted in typical phenotypes of Cdx2-mutant embryos, such as failure of hatching and implantation. However, the blastulation and expression of TE specific markers in these Cdx2-deficient embryos excluded the possibility of Cdx2 to act as a TE determinant, although compromised structure and functioning of TE was observed and the resulted embryos were not viable. Strikingly, the efficiency of stem cell derivation was significantly higher than control when embryos were put on MEF at the 8-cell stage and the derived stem cells were fully pluripotent as shown by chimera and tetraploid complementation experiments. Comparative genomic hybridization of wild type and Cdx2 mutant at 8-cell and blastocyst mouse embryos were performed. 8-cell biological duplicates and blastocyst stage biological triplicates embryos were used.The hybridization experiments were duplicated in a reciprocal labeling manner to reduce dye integration bias (dye-swaps).
Project description:Differentiated cell can be reprogrammed into totipotent embryo through somatic cell nuclear transfer (SCNT). However, this process is highly inefficient and most cloned embryos arrest at certain developmental stages. Through single cell sequencing combined with embryo biopsy, here we generate a global map of DNA methylome and RNA transcriptome for SCNT embryos with distinct developmental fates. We subsequently demonstrate that the unfaithful reactivation of two histone demethylases, Kdm4b and Kdm5b, accounts for the arrest of cloned embryos at 2-cell and 4-cell stage, respectively. Ectopic expression of Kdm4b and Kdm5b in SCNT can remove H3K9me3 barrier, restore the transcription profile and facilitate the blastocyst developmental efficiency over 95%. Moreover, these cloned embryos can further support full-term development and the derivation of SCNT-embryonic stem cells with greater efficiency. Our study reveals that histone methylation reset is crucial for the development of SCNT embryos, which provides a clue to further improve therapeutic cloning. For SCNT embryos 4-8 replicates were performed for each stage . As the control, 3 replicates were performed for each stage of wild type samples
Project description:Differentiated cell can be reprogrammed into totipotent embryo through somatic cell nuclear transfer (SCNT). However, this process is highly inefficient and most cloned embryos arrest at certain developmental stages. Through single cell sequencing combined with embryo biopsy, here we generate a global map of DNA methylome and RNA transcriptome for SCNT embryos with distinct developmental fates. We subsequently demonstrate that the unfaithful reactivation of two histone demethylases, Kdm4b and Kdm5b, accounts for the arrest of cloned embryos at 2-cell and 4-cell stage, respectively. Ectopic expression of Kdm4b and Kdm5b in SCNT can remove H3K9me3 barrier, restore the transcription profile and facilitate the blastocyst developmental efficiency over 95%. Moreover, these cloned embryos can further support full-term development and the derivation of SCNT-embryonic stem cells with greater efficiency. Our study reveals that histone methylation reset is crucial for the development of SCNT embryos, which provides a clue to further improve therapeutic cloning. For SCNT embryos or injected SCNT embryos 3-8 replicates were performed for each stage . As the control, 3-6 replicates were performed for each stage of wild type samples
Project description:Differentiated cell can be reprogrammed into totipotent embryo through somatic cell nuclear transfer (SCNT). However, this process is highly inefficient and most cloned embryos arrest at certain developmental stages. Through single cell sequencing combined with embryo biopsy, here we generate a global map of DNA methylome and RNA transcriptome for SCNT embryos with distinct developmental fates. We subsequently demonstrate that the unfaithful reactivation of two histone demethylases, Kdm4b and Kdm5b, accounts for the arrest of cloned embryos at 2-cell and 4-cell stage, respectively. Ectopic expression of Kdm4b and Kdm5b in SCNT can remove H3K9me3 barrier, restore the transcription profile and facilitate the blastocyst developmental efficiency over 95%. Moreover, these cloned embryos can further support full-term development and the derivation of SCNT-embryonic stem cells with greater efficiency. Our study reveals that histone methylation reset is crucial for the development of SCNT embryos, which provides a clue to further improve therapeutic cloning.
Project description:Differentiated cell can be reprogrammed into totipotent embryo through somatic cell nuclear transfer (SCNT). However, this process is highly inefficient and most cloned embryos arrest at certain developmental stages. Through single cell sequencing combined with embryo biopsy, here we generate a global map of DNA methylome and RNA transcriptome for SCNT embryos with distinct developmental fates. We subsequently demonstrate that the unfaithful reactivation of two histone demethylases, Kdm4b and Kdm5b, accounts for the arrest of cloned embryos at 2-cell and 4-cell stage, respectively. Ectopic expression of Kdm4b and Kdm5b in SCNT can remove H3K9me3 barrier, restore the transcription profile and facilitate the blastocyst developmental efficiency over 95%. Moreover, these cloned embryos can further support full-term development and the derivation of SCNT-embryonic stem cells with greater efficiency. Our study reveals that histone methylation reset is crucial for the development of SCNT embryos, which provides a clue to further improve therapeutic cloning.
Project description:Differentiated cell can be reprogrammed into totipotent embryo through somatic cell nuclear transfer (SCNT). However, this process is highly inefficient and most cloned embryos arrest at certain developmental stages. Through single cell sequencing combined with embryo biopsy, here we generate a global map of DNA methylome and RNA transcriptome for SCNT embryos with distinct developmental fates. We subsequently demonstrate that the unfaithful reactivation of two histone demethylases, Kdm4b and Kdm5b, accounts for the arrest of cloned embryos at 2-cell and 4-cell stage, respectively. Ectopic expression of Kdm4b and Kdm5b in SCNT can remove H3K9me3 barrier, restore the transcription profile and facilitate the blastocyst developmental efficiency over 95%. Moreover, these cloned embryos can further support full-term development and the derivation of SCNT-embryonic stem cells with greater efficiency. Our study reveals that histone methylation reset is crucial for the development of SCNT embryos, which provides a clue to further improve therapeutic cloning.
Project description:Ectopic expression of four transcription factors including Oct4, Sox2, Klf4 and c-Myc in differentiated fibroblast cells could reset the cell fate of fibroblast cells to pluripotent state. Subsequently, fully pluripotency of these so-called induced pluripotent stem cells (iPSCs) has been demonstrated as viable mice could be generated autonomously from iPS cells through tetraploid blastocyst complementation. Moreover, the generation of human and patient-specific iPS cells have raised the possibility of utilizing iPS cells clinically. However, the utilization of c-Myc in iPS cells induction greatly increased the incidence of tumorigenecity in the iPS-chimeric mice and also might hinder the clinical application of human iPS cells in the future. Fortunately, c-Myc has been recently found dispensable for iPS induction even though the iPS induction efficiency is greatly reduced in the absence of c-Myc. However, it remains unknown if these three factors-induced iPS cells are fully pluripotent. In the present study, we have successfully demonstrated that 3-factor iPS cells could also be fully pluripotent as viable mice could be generated from 3-factor iPS cells autonomously via tetraploid complementation and moreover, our data indicated that the pluripotency regulatory mechanism in 3-factor iPS cells might be distinct from 4-factor iPS cells. We compared the gene expression profile of iPS cells with and without the tetraploid embryo complementation competence. Three biological repeats were included for each line.