Differentiated somatic cells are more efficient than adult stem cells for cloning by somatic cell nuclear transfer
Ontology highlight
ABSTRACT: Since the creation of Dolly, the first sheep cloned via somatic cell nuclear transfer (SCNT), in 1997, more than a dozen species of mammals have been cloned using this technology. One hypothesis for the limited success of cloning via SCNT (1-5%) is that the clones are likely derived from adult stem cells, which form an extremely small fraction in most adult tissues. Support for this hypothesis is that the cloning efficiency of full term development using embryonic stem (ES) cells as nuclear donors is 5-10 times higher than that for somatic cells as nuclear donors. Additionally, cloned pups could not be produced directly from cloned embryos derived from nuclei of differentiated B and T cells or neuronal cells. The question remains: can SCNT-derived animal clones be derived from truly differentiated somatic cells? We tested this hypothesis with mouse hematopoietic cells at different differentiation stages: hematopoietic stem cells (HSCs), progenitor cells (HPCs), and granulocytes. Surprisingly, we found that cloning efficiency increases over the differentiation hierarchy. The terminally differentiated post-mitotic granulocytes yielded the greatest cloning efficiency and we produced two cloned pups from granulocytes. We conclude that cloned mammals could be directly derived from post-mitotic differentiated somatic cells. Keywords: cell type comparison
Project description:Since the creation of Dolly, the first sheep cloned via somatic cell nuclear transfer (SCNT), in 1997, more than a dozen species of mammals have been cloned using this technology. One hypothesis for the limited success of cloning via SCNT (1-5%) is that the clones are likely derived from adult stem cells, which form an extremely small fraction in most adult tissues. Support for this hypothesis is that the cloning efficiency of full term development using embryonic stem (ES) cells as nuclear donors is 5-10 times higher than that for somatic cells as nuclear donors. Additionally, cloned pups could not be produced directly from cloned embryos derived from nuclei of differentiated B and T cells or neuronal cells. The question remains: can SCNT-derived animal clones be derived from truly differentiated somatic cells? We tested this hypothesis with mouse hematopoietic cells at different differentiation stages: hematopoietic stem cells (HSCs), progenitor cells (HPCs), and granulocytes. Surprisingly, we found that cloning efficiency increases over the differentiation hierarchy. The terminally differentiated post-mitotic granulocytes yielded the greatest cloning efficiency and we produced two cloned pups from granulocytes. We conclude that cloned mammals could be directly derived from post-mitotic differentiated somatic cells. Experiment Overall Design: single channel Affymetrix arrays to confirm cell-type specific gene expression profiles
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: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.
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. 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:Cloning mammals by somatic cell nuclear transfer (SCNT) is highly inefficient because of aberrant genomic reprogramming. In addition to random reprogramming errors, we hypothesized the presence of specific errors as evidenced by common anomalies among clones. We found that Xist, which normally inactivates one of the two X chromosomes in females, was ectopically expressed from the active X (Xa) chromosome in cloned mouse embryos of both sexes. Deletion of Xist on Xa normalized global gene expression and produced about a 10-fold increase in cloning efficiency. We also identified an Xist-independent mechanism that specifically downregulated a subset of X-linked genes through somatic-type repressive histone blocks. Thus, we have identified nonrandom reprogramming errors in mouse cloning, which provide promising targets for breakthroughs in SCNT cloning technology. Gene expression were measured in mouse in vitro fertilized and somatic cell cloned blastocysts. More than three biological replicates were performed in each group using defferent nuclear donor cells.
Project description:Somatic cell nuclear transfer (SCNT) has been used to clone cynomolgus monkeys (Macaca fascicularis), but the cloning of other non-human primate species remains to be achieved. On the other hand, our histological examination indicated severe calcification of the placenta of SCNT fetuses. Additionally, we found that some of the maternal-biased imprinting genes were aberrantly lost in the cloned embryos by multi-omics analysis. We thus developed a trophoblast replacement (TR) method, providing an ICSI-derived placenta for the SCNT fetus, to support the full-term development of the cloned embryos after implantation. By combining this TR method with treatment with epigenetic modification factors, we obtained a healthy somatic cell cloned rhesus monkey. Thus, TR represents a useful approach for rhesus monkey cloning.
Project description:Somatic cell nuclear transfer (SCNT) has been used to clone cynomolgus monkeys (Macaca fascicularis), but the cloning of other non-human primate species remains to be achieved. On the other hand, our histological examination indicated severe calcification of the placenta of SCNT fetuses. Additionally, we found that some of the maternal-biased imprinting genes were aberrantly lost in the cloned embryos by multi-omics analysis. We thus developed a trophoblast replacement (TR) method, providing an ICSI-derived placenta for the SCNT fetus, to support the full-term development of the cloned embryos after implantation. By combining this TR method with treatment with epigenetic modification factors, we obtained a healthy somatic cell cloned rhesus monkey. Thus, TR represents a useful approach for rhesus monkey cloning.