Subsequent cloning subsequent derivation of stem cells from cloned human embryos. Medical search. Frequent questions

However, following the successful derivation of human embryonic stem cells in 1998, the debate over human cloning largely shifted to the question of whether it is acceptable for scientists to create human embryos only to destroy them. (thenewatlantis.com)
XI - embryonic stem cells: embryonic cells that are capable of modifying the cells of any organism tissue. (hinxtongroup.org)
Thus, telomerase activity and telomere maintenance are associated with the immortality of cancer cells, germ-line cells, and embryonic stem (ES) cells. (nature.com)
We have previously demonstrated the utility and developmental neutrality of enhanced green fluorescent protein (EGFP) in embryonic stem (ES) cells and mice [ 2 ]. (biomedcentral.com)
In this study we have used embryonic stem (ES) cell-mediated transgenesis to test the enhanced cyan fluorescent protein (ECFP) and enhanced yellow fluorescent protein (EYFP), two mutant and spectrally distinct color variants of wild type (wt) GFP. (biomedcentral.com)
Conditional deletion indicates that Dab2 is dispensable for organ development, when the vast majority of the embryonic cells are dab2 null. (biomedcentral.com)

They showed that opposing gradients of bone morphogenetic protein (BMP) and Nodal, two transforming growth factor family members that act as morphogens, are sufficient to induce molecular and cellular mechanisms required to organize, in vivo or in vitro, uncommitted cells of the zebrafish blastula animal pole into a well-developed embryo. (wikipedia.org)

Mechanochemical Principles of Spatial and Temporal Patterns in Cells and Tissues. (mpi-cbg.de)
Patterns are ubiquitous in living systems and underlie the dynamic organization of cells, tissues, and embryos. (mpi-cbg.de)
The ECFP and EYFP-expressing transgenic ES cells and mice that we have generated provide sources of cells and tissues for combinatorial, double-tagged recombination experiments, chimeras or transplantations. (biomedcentral.com)
However, the mice were grossly normal when dab2 deletion was restricted to the embryo proper and the gene was retained in extraembryonic tissues using Meox2-Cre and Sox2-Cre. (biomedcentral.com)

This form of genetic engineering would deny the children it produces an open future, burdening them with the expectation that they will be like the individuals from whom they were cloned. (thenewatlantis.com)
And cloning could make possible still more dramatic forms of genetic engineering. (thenewatlantis.com)
In Enhancing Evolution, leading bioethicist John Harris dismantles objections to genetic engineering, stem-cell research, designer babies, and cloning and makes an ethical case for biotechnology that is both forthright and rigorous. (philpapers.org)
Human enhancement, Harris argues, is a good thing--good morally, good for individuals, good as social policy, and good for a genetic heritage that needs serious improvement. (philpapers.org)
Recently, the importance of telomere maintenance in human stem cells has been highlighted by studies on dyskeratosis congenital, which is a genetic disorder in the human telomerase component. (nature.com)
In addition to these basic issues concerning leukemia pathogenesis, we are devising new diagnostic procedures for detecting and monitoring leukemia patients based on molecular genetic abnormalities in the malignant cells. (stanford.edu)

They form characteristic cell clusters in suspension culture that express a set of genes associated with pluripotency and can differentiate into endodermal, ectodermal and mesodermal cells both in vitro and in vivo. (wikipedia.org)
… "human clone" means an embryo that, as a result of the manipulation of human reproductive material or an in vitro embryo, contains a diploid set of chromosomes obtained from a single - living or deceased - human being, fetus, or embryo. (hinxtongroup.org)
In vitro studies indicate that Dab2 establishes epithelial cell polarity and organization by directing endocytic trafficking of membrane glycoproteins. (biomedcentral.com)

Induced totipotent cells can be obtained by reprogramming somatic cells with somatic-cell nuclear transfer (SCNT). (wikipedia.org)
In somatic cells, the activity of telomerase, a reverse transcriptase that can elongate telomeric repeats, is usually diminished after birth so that the telomere length is gradually shortened with cell divisions, and triggers cellular senescence. (nature.com)
Thus, even in stem cells, except for embryonal stem cells and cancer stem cells, telomere shortening occurs during replicative ageing, possibly at a slower rate than that in normal somatic cells. (nature.com)
Telomeric DNA consists of short guanine-rich repeat sequences in all eukaryotes with linear chromosomes, and its length in human somatic cells is remarkably heterogeneous among individuals ranging from 5 to 20 kb, according to age, organ, and the proliferative history of each cell ( Wright and Shay, 2005 ). (nature.com)
In most human somatic cells except for stem cells and lymphocytes, telomerase activity is diminished after birth so that telomere length shortens with each cell division. (nature.com)

Cloning-to-produce-children could also be used to attempt to control the physical and even psychological traits of children, extending the eugenic logic of those who would use reproductive biotechnology to have the perfect child. (thenewatlantis.com)
Other policy options, such as supposed compromises that would prohibit "reproductive cloning" but permit "therapeutic cloning" by prohibiting not the act of creating a cloned embryo but the act of transferring a cloned embryo to a woman's uterus, would inherently mandate the wide-scale destruction of human embryos. (thenewatlantis.com)
Induced stem cells (iSC) are stem cells derived from somatic, reproductive, pluripotent or other cell types by deliberate epigenetic reprogramming. (wikipedia.org)

Basically, given the difference of telomere and telomerase activity in human and mouse cells, the telomere and telomerase status in stem cell populations is different between humans and mice ( Harrington, 2004 ). (nature.com)
diploid) chimeras comprising combinations of the ECFP and EYFP ES cells and/or embryos, demonstrate that populations of cells expressing each individual reporter can be distinguished within a single animal. (biomedcentral.com)

Differentiated airway epithelial cells can revert into stable and functional stem cells in vivo. (wikipedia.org)
In fact, low levels of telomerase activity have been found in human adult stem cells including haematopoietic and non-haematopoietic stem cells such as neuronal, skin, intestinal crypt, mammary epithelial, pancreas, adrenal cortex, kidney, and mesenchymal stem cells (MSCs) ( Table 1 ). (nature.com)
The study of the new dab2 mutant allele in embryos and embryoid bodies confirms a role for Dab2 in extraembryonic endoderm development and epithelial organization. (biomedcentral.com)

The report offers an ethical and policy analysis, articulating what makes cloning morally repugnant and calling for the practice to be definitively prohibited in the United States. (thenewatlantis.com)

To this end, we have established lines of ES cells together with viable and fertile mice having widespread expression of either the ECFP or EYFP GFP-variant reporters. (biomedcentral.com)
He probes the male mouse's reaction to chemical signals from female mice to advance understanding of pattern recognition and learning in the much more complex human brain. (vetscite.org)

When the world learned in 1997 of Dolly the sheep, the first clone produced from an adult mammal, a broad public discussion about the ethics of human cloning ensued, largely focused on the nature, meaning, and future of human procreation. (thenewatlantis.com)
One example is the transformation of iris cells to lens cells in the process of maturation and transformation of retinal pigment epithelium cells into the neural retina during regeneration in adult newt eyes. (wikipedia.org)
Some types of mature, specialized adult cells can naturally revert to stem cells. (wikipedia.org)
For instance, multilineage-differentiating stress-enduring (Muse) cells are stress-tolerant adult human stem cells that can self-renew. (wikipedia.org)

Nat Rev Mol Cell Biol , Art. (mpi-cbg.de)

We demonstrate here that GSK-3 maintains the MLL leukemia stem cell transcriptional program by promoting the conditional association of CREB and its coactivators TORC and CBP with homedomain protein MEIS1, a critical component of the MLL-subordinate program, which in turn facilitates HOX-mediated transcription and transformation. (stanford.edu)

If research cloning is not stopped now, we face the prospect of the mass farming of human embryos and fetuses, and the transformation of the noble enterprise of biomedical research into a grotesque system of exploitation and death. (thenewatlantis.com)
The reversible transformation of cells of one differentiated cell type to another is called metaplasia. (wikipedia.org)
Our research focuses on developmental pathways that regulate hematopoietic cell growth and differentiation and are disrupted in the course of neoplastic transformation, particularly in leukemias and lymphomas. (stanford.edu)

They are classified as either totipotent (iTC), pluripotent (iPSC) or progenitor (multipotent - iMSC, also called an induced multipotent progenitor cell - iMPC) or unipotent - (iUSC) according to their developmental potential and degree of dedifferentiation. (wikipedia.org)

A critical length of telomere repeats is required to ensure proper telomere function and avoid the activation of DNA damage pathways that result in replicative senescence or cell death. (nature.com)

Both directed and random mutagenesis approaches, including the technologies of transgenesis and gene targeting in ES cells, have become commonplace. (biomedcentral.com)
Fluorescent protein reporters currently represent a superior alternative to other gene-based reporters such as the bacterial lacZ or human placental alkaline phosphatase in that their visualization is non-invasive, and as such does not require chromogenic substrates. (biomedcentral.com)
We are studying the role that normal chromatin structure plays in gene regulation in hematopoietic cells and how its disruption leads to altered development and cancer. (stanford.edu)
A fragment of the Dab2 human cDNA was also isolated based on its frequent loss of expression in ovarian cancer, and was termed DOC-2 (Differentially expressed in ovarian carcinoma gene 2) [ 2 ]. (biomedcentral.com)

To take human organ generation via BC and transplantation to the next step, we reviewed current emerging organ generation technologies and the associated efficiency of chimera formation in human cells from the standpoint of developmental biology. (frontiersin.org)

In a new preface, Harris offers a glimpse at the new science and technology to come, equipping readers with the knowledge to assess the ethics and policy dimensions of future forms of human enhancement. (philpapers.org)

But cloning research continued, and American scientists announced in 2013 that they had for the first time successfully obtained stem cells from cloned human embryos. (thenewatlantis.com)
Although the latest scientific work related to cloning has been focused on potential medical applications, much of that research is relevant to the creation of cloned children. (thenewatlantis.com)
Cloning-for-biomedical-research is also profoundly unethical, as it turns human reproduction into a manufacturing process in the most literal sense: human embryos are created to serve as raw materials for the production of biomedical research supplies. (thenewatlantis.com)
Cloning-for-biomedical-research also endangers the health and safety of the women called on to undergo dangerous hormone treatments to serve as egg donors. (thenewatlantis.com)
The Threat of Human Cloning concludes by calling for laws prohibiting both human cloning and the creation of embryos for research. (thenewatlantis.com)

… "embryo" means a human organism during the first 56 days of its development following fertilization or creation, excluding any time during which its development has been suspended, and includes any cell derived from such an organism that is used for the purpose of creating a human being. (hinxtongroup.org)
On the other hand, a chimera is defined as an organism in which cells from two or more different organisms have contributed. (frontiersin.org)

After injury, mature terminally differentiated kidney cells dedifferentiate into more primordial versions of themselves and then differentiate into the cell types needing replacement in the damaged tissue Macrophages can self-renew by local proliferation of mature differentiated cells. (wikipedia.org)

Progenitors are obtained by so-called direct reprogramming or directed differentiation and are also called induced somatic stem cells. (wikipedia.org)
This meant that the cells can change their differentiation pathway. (wikipedia.org)
In Drosophila imaginal discs, cells have to choose from a limited number of standard discrete differentiation states. (wikipedia.org)
The fact that transdetermination (change of the path of differentiation) often occurs for a group of cells rather than single cells shows that it is induced rather than part of maturation. (wikipedia.org)

While they normally produce digestive fluids for the stomach, they can revert into stem cells to make temporary repairs to stomach injuries, such as a cut or damage from infection. (wikipedia.org)
Moreover, they can make this transition even in the absence of noticeable injuries and are capable of replenishing entire gastric units, in essence serving as quiescent "reserve" stem cells. (wikipedia.org)
This capacity to regenerate does not decline with age and may be linked to their ability to make new stem cells from muscle cells on demand. (wikipedia.org)
The Honeycomb Game is a word-building game: make words by clicking on cells in the honeycomb below. (claylane.uk)

Influence on the Cells Membrane Permeability and Integrity Cell membrane integrity is crucial for cell features and success. (forgetmenotinitiative.org)

In this regard, emerging technologies of chimeric human organ production via blastocyst complementation (BC) holds great promise. (frontiersin.org)
However, though BC is emerging as a potential organ transplant option, challenges regarding organ size scalability, immune system incompatibilities, long-term maintenance, potential evolutionary distance, or unveiled mechanisms between donor and host cells remain. (frontiersin.org)
In this review, we summarize the history of interspecies chimerism in various animal models to find hints for BC application and describe the challenges and prospects of utilizing BC for human organ generation. (frontiersin.org)

H uman cloning has advanced considerably since it was last widely debated. (thenewatlantis.com)

The researchers were able to identify the minimal conditions and factors that would be sufficient for starting the cascade of molecular and cellular processes to instruct pluripotent cells to organize the embryo. (wikipedia.org)
Telomerase can add telomeric repeats onto the chromosome ends, and prevents the replication-dependent loss of telomere and cellular senescence in highly proliferative cells of the germline and in the majority of cancers ( Blasco, 2005 ). (nature.com)

Not only would cloning-to-produce-children be a dangerous experimental procedure, one that cannot be consented to by its subjects (the children created by it), it is also a profound distortion of the moral meaning of human procreation. (thenewatlantis.com)

As stem cells have elongated proliferative capacity, they should have a mechanism that maintains telomere length through many cell divisions. (nature.com)

This process allows the body to replace cells not suitable to new conditions with more suitable new cells. (wikipedia.org)
The process involves sucking out the nucleus of a somatic (body) cell and injecting it into an oocyte that has had its nucleus removed Using an approach based on the protocol outlined by Tachibana et al. (wikipedia.org)
The regulation of telomere length and telomerase activity is a complex and dynamic process that is tightly linked to cell cycle regulation in human stem cells. (nature.com)

The subsequent discovery of promising alternative techniques for generating stem cells without creating or destroying embryos seemed to show that scientific progress would obviate the demand for cloning. (thenewatlantis.com)
This kind of cloning is today being performed at several scientific labs in the United States, despite the availability of alternative techniques that produce cells of nearly the same scientific and medical value but that require neither the creation nor destruction of human embryos. (thenewatlantis.com)

Modulation of LDL receptor endocytosis by Dab2 has also been studied in cultured cells [ 36 ], though a role in vivo has not yet been established. (biomedcentral.com)

In 1895 Thomas Morgan removed one of a frog's two blastomeres and found that amphibians are able to form whole embryos from the remaining part. (wikipedia.org)
They found the compounds activate nerve cells in the male mouse's nose with unprecedented effectiveness. (vetscite.org)

In newts, muscle tissue is regenerated from specialized muscle cells that dedifferentiate and forget the type of cell they had been. (wikipedia.org)

The Threat of Human Cloning begins by laying out the scientific and policy background of the cloning debates. (thenewatlantis.com)

This report - written to be understood by non-specialists, including policymakers and the general public - explains the history of cloning as well as recent developments. (thenewatlantis.com)
In ancient history, humans used the term "chimera" to describe mythical creatures and hybrids. (frontiersin.org)

Here we review the role of telomeres and telomerase in the function and capacity of the human stem cells. (nature.com)

In 1924 Hans Spemann and Hilde Mangold demonstrated the key importance of cell-cell inductions during animal development. (wikipedia.org)
3) We are defining the properties of cancer stem cells that initiate and sustain the unique disease features of acute leukemias through the use of various adoptive animal models. (stanford.edu)

Because of lipophilic nature from the cell membranes, monoterpenes could cause their devastation by raising permeability or inhibiting enzymes [18]. (forgetmenotinitiative.org)

A variety of nontumorigenic stem cells display the ability to generate multiple cell types. (wikipedia.org)
A genuine variety of allelochemicals appear to alter place cell membranes. (forgetmenotinitiative.org)

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