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: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:Pluripotent cells can be derived from somatic cells by either overexpression of defined transcription factors (resulting in induced pluripotent stem cells (iPSCs)) or by nuclear transfer or cloning (resulting in NT-ESCs). To determine whether cloning further reprograms iPSCs, we used iPSCs as donor cells in nuclear transfer experiments.
Project description:Pluripotent cells can be derived from somatic cells by either overexpression of defined transcription factors (resulting in induced pluripotent stem cells (iPSCs)) or by nuclear transfer or cloning (resulting in NT-ESCs). To determine whether cloning further reprograms iPSCs, we used iPSCs as donor cells in nuclear transfer experiments. An iPSC clone derived from tail-tip fibroblasts using adenoviral vectors was used as donor cell in nuclear transfer experiments. RNA was isolated from both parental iPSC clone and derivative NT-ESCs lines and analyzed.
Project description:The transfer of somatic cell nuclei into oocytes can give rise to pluripotent stem cells, holding promise for autologous cell replacement therapy. Though reprogramming of somatic cells by nuclear transfer was first demonstrated more than 60 years ago, only recently have human diploid embryonic stem cells been derived after nuclear transfer of fetal and neonatal fibroblasts. Because of the therapeutic potential of developing diploid embryonic stem cell lines from adult cells of normal and diseased human subjects, we have systematically investigated the parameters affecting efficiency and developmental potential in their derivation. We found that improvements to the oocyte activation protocol, including the use of both a kinase and a translation inhibitor, and cell culture in the presence of histone deacetylase inhibitors enable development of diploid cells to the blastocyst stage. Developmental efficiency varied significantly between oocyte donors, and was inversely related to the number of days of hormonal stimulation required to reach mature oocytes, while the daily dose of gonadotropin or the total number of MII oocytes retrieved did not affect developmental outcome. The use of diluted Sendai virus in calcium-free medium during nuclear transfer improved developmental potential, while the use of concentrated Sendai virus induced an increase in intracellular calcium and caused premature oocyte activation. Using these modifications to the nuclear transfer protocol, we successfully derived diploid pluripotent stem cell lines from both postnatal and adult somatic cells of a type 1 diabetic subject. Gene expression analysis was performed on a total of 5 human cell lines, including an isogenic set of 3 nuclear-transfer embryonic stem cell lines and their parental neonatal fibroblast cell line, as well as a fourth nuclear-transfer embryonic stem cell line, which was derived from adult fibroblasts from a type 1 diabetic subject.
Project description:The transfer of somatic cell nuclei into oocytes can give rise to pluripotent stem cells, holding promise for autologous cell replacement therapy. Though reprogramming of somatic cells by nuclear transfer was first demonstrated more than 60 years ago, only recently have human diploid embryonic stem cells been derived after nuclear transfer of fetal and neonatal fibroblasts. Because of the therapeutic potential of developing diploid embryonic stem cell lines from adult cells of normal and diseased human subjects, we have systematically investigated the parameters affecting efficiency and developmental potential in their derivation. We found that improvements to the oocyte activation protocol, including the use of both a kinase and a translation inhibitor, and cell culture in the presence of histone deacetylase inhibitors enable development of diploid cells to the blastocyst stage. Developmental efficiency varied significantly between oocyte donors, and was inversely related to the number of days of hormonal stimulation required to reach mature oocytes, while the daily dose of gonadotropin or the total number of MII oocytes retrieved did not affect developmental outcome. The use of diluted Sendai virus in calcium-free medium during nuclear transfer improved developmental potential, while the use of concentrated Sendai virus induced an increase in intracellular calcium and caused premature oocyte activation. Using these modifications to the nuclear transfer protocol, we successfully derived diploid pluripotent stem cell lines from both postnatal and adult somatic cells of a type 1 diabetic subject. The goal of this experiment was to determine if human oocytes have the ability to reprogram a somatic cell genome in the absence of the oocyte genome. Our previous research had indicated that human oocytes can reprogram adult somatic cells if the oocyte genome remains present (Noggle et al. Nature 2011, doi:10.1038/nature10397). The data presented here is part of a new series of experiments aimed at obtaining diploid cells after somatic cell nuclear transfer into enucleated oocytes. In this experiment, adult somatic cells were transferred into enucleated oocytes and thereafter cultured in the presence of 240ng/ml scriptaid for 17 hours. Samples were cultured until cleavage stage and then collected for microarray analysis.
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:Derivation of embryonic stem cells (ESC) genetically identical to a patient by somatic cell nuclear transfer (SCNT) holds the potential to cure or alleviate the symptoms of many degenerative diseases while circumventing any immunorejection issues. However, no primate nuclear transfer embryonic stem (ntES) cell lines have been derived to date. Here, we used a modified SCNT technique to produce rhesus macaque SCNT blastocysts at a relatively high efficiency from adult donor cells and we successfully derived two primate ntES cell lines from 304 oocytes (an overall efficiency of 0.7%). Nuclear and mitochondrial DNA analysis confirmed the ntES cell lines were derived from rhesus monkey SCNT blastocysts and both rhesus monkey ntES cell lines exhibited a normal ESC morphology, expressed key stemness markers, were transcriptionally indistinguishable from control ESC lines and differentiated into multiple cell types. This is, to our knowledge, the first confirmed derivation of primate ntES cell lines. Keywords: rhesus monkey somatic cell nuclear transfer embryonic stem cells
Project description:The transfer of somatic cell nuclei into oocytes can give rise to pluripotent stem cells, holding promise for autologous cell replacement therapy. Though reprogramming of somatic cells by nuclear transfer was first demonstrated more than 60 years ago, only recently have human diploid embryonic stem cells been derived after nuclear transfer of fetal and neonatal fibroblasts. Because of the therapeutic potential of developing diploid embryonic stem cell lines from adult cells of normal and diseased human subjects, we have systematically investigated the parameters affecting efficiency and developmental potential in their derivation. We found that improvements to the oocyte activation protocol, including the use of both a kinase and a translation inhibitor, and cell culture in the presence of histone deacetylase inhibitors enable development of diploid cells to the blastocyst stage. Developmental efficiency varied significantly between oocyte donors, and was inversely related to the number of days of hormonal stimulation required to reach mature oocytes, while the daily dose of gonadotropin or the total number of MII oocytes retrieved did not affect developmental outcome. The use of diluted Sendai virus in calcium-free medium during nuclear transfer improved developmental potential, while the use of concentrated Sendai virus induced an increase in intracellular calcium and caused premature oocyte activation. Using these modifications to the nuclear transfer protocol, we successfully derived diploid pluripotent stem cell lines from both postnatal and adult somatic cells of a type 1 diabetic subject.
Project description:The transfer of somatic cell nuclei into oocytes can give rise to pluripotent stem cells, holding promise for autologous cell replacement therapy. Though reprogramming of somatic cells by nuclear transfer was first demonstrated more than 60 years ago, only recently have human diploid embryonic stem cells been derived after nuclear transfer of fetal and neonatal fibroblasts. Because of the therapeutic potential of developing diploid embryonic stem cell lines from adult cells of normal and diseased human subjects, we have systematically investigated the parameters affecting efficiency and developmental potential in their derivation. We found that improvements to the oocyte activation protocol, including the use of both a kinase and a translation inhibitor, and cell culture in the presence of histone deacetylase inhibitors enable development of diploid cells to the blastocyst stage. Developmental efficiency varied significantly between oocyte donors, and was inversely related to the number of days of hormonal stimulation required to reach mature oocytes, while the daily dose of gonadotropin or the total number of MII oocytes retrieved did not affect developmental outcome. The use of diluted Sendai virus in calcium-free medium during nuclear transfer improved developmental potential, while the use of concentrated Sendai virus induced an increase in intracellular calcium and caused premature oocyte activation. Using these modifications to the nuclear transfer protocol, we successfully derived diploid pluripotent stem cell lines from both postnatal and adult somatic cells of a type 1 diabetic subject.