1
|
Churbanov A, Abrahamyan L. Preventing Common Hereditary Disorders through Time-Separated Twinning. BIONANOSCIENCE 2018. [DOI: 10.1007/s12668-017-0488-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
2
|
King ML. Maternal messages to live by: a personal historical perspective. Genesis 2017; 55:10.1002/dvg.23007. [PMID: 28095642 PMCID: PMC5276792 DOI: 10.1002/dvg.23007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 11/22/2016] [Accepted: 11/24/2016] [Indexed: 12/17/2022]
Abstract
In the 1980s, the study of localized maternal mRNAs was just emerging as a new research area. Classic embryological studies had linked the inheritance of cytoplasmic domains with specific cell lineages, but the underlying molecular nature of these putative determinants remained a mystery. The model system Xenopus would play a pivotal role in the progress of this new field. In fact, the first localized maternal mRNA to be identified and cloned from any organism was Xenopus vg1, a TGF-beta family member. This seminal finding opened the door to many subsequent studies focused on how RNAs are localized and what functions they had in development. As the field moves into the future, Xenopus remains the system of choice for studies identifying RNA/protein transport particles and maternal RNAs through RNA-sequencing.
Collapse
Affiliation(s)
- Mary Lou King
- Department of Cell Biology, University of Miami Miller School of Medicine, 1011 NW 15th St, Miami, FL 33136, USA
| |
Collapse
|
3
|
Aggregation of cloned embryos in empty zona pellucida improves derivation efficiency of pig ES-like cells. ZYGOTE 2016; 24:909-917. [PMID: 27692031 DOI: 10.1017/s0967199416000241] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The development of embryonic stem cells (ESCs) from large animal species has become an important model for therapeutic cloning using ESCs derived by somatic cell nuclear transfer (SCNT). However, poor embryo quality and blastocyst formation have been major limitations for derivation of cloned ESCs (ntESCs). In this study, we have tried to overcome these problems by treating these cells with histone deacetylase inhibitors (HDACi) and aggregating porcine embryos. First, cloned embryos were treated with Scriptaid to confirm the effect of HDACi on cloned embryo quality. The Scriptaid-treated blastocysts showed significantly higher total cell numbers (29.50 ± 2.10) than non-treated blastocysts (22.29 ± 1.50, P < 0.05). Next, cloned embryo quality and blastocyst formation were analyzed in aggregates. Three zona-free, reconstructed, four-cell-stage SCNT embryos were injected into the empty zona of hatched parthenogenetic (PA) blastocysts. Blastocyst formation and total cell number of cloned blastocysts increased significantly for all aggregates (76.4% and 83.18 ± 8.33) compared with non-aggregates (25.5% and 27.11 ± 1.67, P < 0.05). Finally, aggregated blastocysts were cultured on a feeder layer to examine the efficiency of porcine ES-like cell derivation. Aggregated blastocysts showed a higher primary colony formation rate than non-aggregated cloned blastocysts (17.6 ± 12.3% vs. 2.2 ± 1.35%, respectively, P < 0.05). In addition, derived ES-like cells showed typical characters of ESCs. In conclusion, the aggregation of porcine SCNT embryos at the four-cell stage could be a useful technique for improving the development rate and quality of porcine-cloned blastocysts and the derivation efficiency of porcine ntESCs.
Collapse
|
4
|
Abstract
Abstract Professor Keith Campbell's critical contribution to the discovery that a somatic cell from an adult animal can be fully reprogrammed by oocyte factors to form a cloned individual following nuclear transfer (NT)(Wilmut et al., 1997 ) overturned a dogma concerning the reversibility of cell fate that many scientists had considered to be biologically impossible. This seminal experiment proved the totipotency of adult somatic nuclei and finally confirmed that adult cells could differentiate without irreversible changes to the genetic material.
Collapse
|
5
|
Feng R, Lengner C. Application of Stem Cell Technology in Dental Regenerative Medicine. Adv Wound Care (New Rochelle) 2013; 2:296-305. [PMID: 24527351 DOI: 10.1089/wound.2012.0375] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Indexed: 12/19/2022] Open
Abstract
SIGNIFICANCE In this review, we summarize the current literature regarding the isolation and characterization of dental tissue-derived stem cells and address the potential of these cell types for use in regenerative cell transplantation therapy. RECENT ADVANCES Looking forward, platforms for the delivery of stem cells via scaffolds and the use of growth factors and cytokines for enhancing dental stem cell self-renewal and differentiation are discussed. CRITICAL ISSUES We aim to understand the developmental origins of dental tissues in an effort to elucidate the molecular pathways governing the genesis of somatic dental stem cells. The advantages and disadvantages of several dental stem cells are discussed, including the developmental stage and specific locations from which these cells can be purified. In particular, stem cells from human exfoliated deciduous teeth may act as a very practical and easily accessibly reservoir for autologous stem cells and hold the most value in stem cell therapy. Dental pulp stem cells and periodontal ligament stem cells should also be considered for their triple lineage differentiation ability and relative ease of isolation. Further, we address the potentials and limitations of induced pluripotent stem cells as a cell source in dental regenerative. FUTURE DIRECTIONS From an economical and a practical standpoint, dental stem cell therapy would be most easily applied in the prevention of periodontal ligament detachment and bone atrophy, as well as in the regeneration of dentin-pulp complex. In contrast, cell-based tooth replacement due to decay or other oral pathology seems, at the current time, an untenable approach.
Collapse
Affiliation(s)
- Ruoxue Feng
- School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Chistopher Lengner
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| |
Collapse
|
6
|
Seffer I, Nemeth Z, Hoffmann G, Matics R, Seffer AG, Koller A. Unexplored potentials of epigenetic mechanisms of plants and animals-theoretical considerations. GENETICS & EPIGENETICS 2013; 5:23-41. [PMID: 25512705 PMCID: PMC4222336 DOI: 10.4137/geg.s11752] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Morphological and functional changes of cells are important for adapting to environmental changes and associated with continuous regulation of gene expressions. Genes are regulated–in part–by epigenetic mechanisms resulting in alternating patterns of gene expressions throughout life. Epigenetic changes responding to the environmental and intercellular signals can turn on/off specific genes, but do not modify the DNA sequence. Most epigenetic mechanisms are evolutionary conserved in eukaryotic organisms, and several homologs of epigenetic factors are present in plants and animals. Moreover, in vitro studies suggest that the plant cytoplasm is able to induce a nuclear reassembly of the animal cell, whereas others suggest that the ooplasm is able to induce condensation of plant chromatin. Here, we provide an overview of the main epigenetic mechanisms regulating gene expression and discuss fundamental epigenetic mechanisms and factors functioning in both plants and animals. Finally, we hypothesize that animal genome can be reprogrammed by epigenetic factors from the plant protoplast.
Collapse
Affiliation(s)
| | - Zoltan Nemeth
- Seffer-Renner Medical Clinic, Budapest, Hungary. ; Department of Pathophysiology and Gerontology, Medical School, and Szentagothai Res Centre, University of Pecs, Pecs, Hungary
| | - Gyula Hoffmann
- Institute of Biology, Faculty of Sciences, University of Pecs, Pecs, Hungary
| | - Robert Matics
- Department of Pathophysiology and Gerontology, Medical School, and Szentagothai Res Centre, University of Pecs, Pecs, Hungary
| | - A Gergely Seffer
- Surgery Clinic, Medical School, University of Pecs, Pecs, Hungary
| | - Akos Koller
- Department of Pathophysiology and Gerontology, Medical School, and Szentagothai Res Centre, University of Pecs, Pecs, Hungary. ; Department of Physiology, New York Medical College, Valhalla NY, USA
| |
Collapse
|
7
|
BYRNE JAMESA. NUCLEAR REPROGRAMMING AND THE CURRENT CHALLENGES IN ADVANCING PERSONALIZED PLURIPOTENT STEM CELL-BASED THERAPIES. ACTA ACUST UNITED AC 2012. [DOI: 10.1142/s1568558612300028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
8
|
Jeon HY, Jeong YW, Kim YW, Jeong YI, Hossein SM, Yang H, Hyun SH, Jeung EB, Hwang WS. Senescence is accelerated through donor cell specificity in cloned pigs. Int J Mol Med 2012; 30:383-91. [PMID: 22614175 DOI: 10.3892/ijmm.2012.1003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 04/27/2012] [Indexed: 11/05/2022] Open
Abstract
Animals cloned by somatic cell nuclear transfer (SCNT) sometimes have abnormalities that result in large offspring syndrome or early death during gestation due to respiratory and metabolic defects. We cloned pigs using two sources of donor cells and observed phenotypic anomalies in three pigs cloned from one type of cell, s-pig fetal fibroblasts. These animals had many wrinkles on their faces and bodies and looked older than age-matched normal pigs. We performed the present study to examine whether the wrinkled phenotype in the cloned pigs was due to senescence, a genetic problem with donor specificity, or epigenetic problems with reprogramming. To address this issue, we investigated biomarkers of senescence, including telomere length and the expression of senescence-associated β-galactosidase (SA-β-gal), glyceraldehyde phosphate dehydrogenase (GAPDH) and β-actin. We also assessed the methylation status of euchromatic PRE-1 repetitive sequences and centromeric satellite DNA, and measured the mRNA levels of six imprinted genes, Copg2, Mest, Igf2R, GNAS, SNRPN and Ube3a. The telomeres of the wrinkled cloned pigs were much shorter than those of the normal cloned pigs and age-matched normal pigs. In the wrinkled cloned pigs, SA-β-gal activity was detected and GAPDH and β-actin were repressed. The mRNA levels of Mest, GNAS and Ube3a were reduced in the wrinkled cloned pigs, although there was no difference between the normal cloned pigs and normal controls. This gene expression analysis indicates that the wrinkled abnormality of our pigs originates from genetic abnormalities in the donor cells used for SCNT.
Collapse
Affiliation(s)
- Hyun Yong Jeon
- Sooam Biotech Research Foundation, Guro-gu, Seoul 152-904, Republic of Korea
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Choi I, Lee JH, Fisher P, Campbell KH. Caffeine treatment of ovine cytoplasts regulates gene expression and foetal development of embryos produced by somatic cell nuclear transfer. Mol Reprod Dev 2010; 77:876-87. [DOI: 10.1002/mrd.21230] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
10
|
Sparrow R. Therapeutic cloning and reproductive liberty. THE JOURNAL OF MEDICINE AND PHILOSOPHY 2009; 34:102-18. [PMID: 19240247 DOI: 10.1093/jmp/jhp014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Concern for "reproductive liberty" suggests that decisions about embryos should normally be made by the persons who would be the genetic parents of the child that would be brought into existence if the embryo were brought to term. Therapeutic cloning would involve creating and destroying an embryo, which, if brought to term, would be the offspring of the genetic parents of the person undergoing therapy. I argue that central arguments in debates about parenthood and genetics therefore suggest that therapeutic cloning would be prima facie unethical unless it occurred with the consent of the parents of the person being cloned. Alternatively, if therapeutic cloning is thought to be legitimate, this undermines the case for some uses of reproductive cloning by implying that the genetic relation it establishes between clones and DNA donors does not carry the same moral weight as it does in cases of normal reproduction.
Collapse
Affiliation(s)
- Robert Sparrow
- Centre for Human Bioethics, Monash University, Clayton, Victoria 3800, Australia.
| |
Collapse
|
11
|
Mitalipov S, Wolf D. Totipotency, pluripotency and nuclear reprogramming. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2009; 114:185-99. [PMID: 19343304 PMCID: PMC2752493 DOI: 10.1007/10_2008_45] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Mammalian development commences with the totipotent zygote which is capable of developing into all the specialized cells that make up the adult animal. As development unfolds, cells of the early embryo proliferate and differentiate into the first two lineages, the pluripotent inner cell mass and the trophectoderm. Pluripotent cells can be isolated, adapted and propagated indefinitely in vitro in an undifferentiated state as embryonic stem cells (ESCs). ESCs retain their ability to differentiate into cells representing the three major germ layers: endoderm, mesoderm or ectoderm or any of the 200+ cell types present in the adult body. Since many human diseases result from defects in a single cell type, pluripotent human ESCs represent an unlimited source of any cell or tissue type for replacement therapy thus providing a possible cure for many devastating conditions. Pluripotent cells resembling ESCs can also be derived experimentally by the nuclear reprogramming of somatic cells. Reprogrammed somatic cells may have an even more important role in cell replacement therapies since the patient's own somatic cells can be used for reprogramming thereby eliminating immune based rejection of transplanted cells. In this review, we summarize two major approaches to reprogramming: (1) somatic cell nuclear transfer and (2) direct reprogramming using genetic manipulations.
Collapse
Affiliation(s)
- Shoukhrat Mitalipov
- Division of Reproductive Sciences, Oregon National Primate Research Center, Oregon Health and Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA; Oregon Stem Cell Center, Oregon Health and Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA; and Department of Obstetrics and Gynecology, School of Medicine, Oregon Health and Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA,
| | - Don Wolf
- Division of Reproductive Sciences, Oregon National Primate Research Center, Oregon Health and Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| |
Collapse
|
12
|
Egli D, Birkhoff G, Eggan K. Mediators of reprogramming: transcription factors and transitions through mitosis. Nat Rev Mol Cell Biol 2008; 9:505-16. [PMID: 18568039 DOI: 10.1038/nrm2439] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
It is thought that most cell types of the human body share the same genetic information as that contained in the zygote from which they originate. Consistent with this view, animal cloning studies demonstrated that the intact genome of a differentiated cell can be reprogrammed to support the development of an entire organism and allow the production of pluripotent stem cells. Recent progress in reprogramming research now points to an important role for transcription factors in the establishment and the maintenance of cellular phenotypes, and to cell division as a mediator of transitions between different states of gene expression.
Collapse
Affiliation(s)
- Dieter Egli
- The Stowers Medical Institute, Harvard Stem Cell Institute and the Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | | | | |
Collapse
|
13
|
Wakayama S, Cummins JM, Wakayama T. Nuclear reprogramming to produce cloned mice and embryonic stem cells from somatic cells. Reprod Biomed Online 2008; 16:545-52. [PMID: 18413064 DOI: 10.1016/s1472-6483(10)60462-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Cloning methods in mice are now well described and are becoming routine. However, the frequency at which cloned mice are produced remains below 5%, irrespective of the nucleus donor species or cell type. Only a few laboratories have made clones from adult mouse somatic cells and most strains have never produced cloned mice. On the other hand, nuclear transfer can be used to generate human embryonic stem (ntES) cell lines from a patient's own somatic cells. It has been shown that such cells can be generated relatively easily from a variety of mouse genotypes and cell types of both sexes, even though it may be more difficult to generate clones directly. This technique could be used in regenerative medicine and, in theory, in infertility clinics to treat completely infertile individuals. However, these results suggest that the reprogramming integrity of each cloned embryo differs: some cloned embryos can be converted to ntES cells, but these embryos cannot achieve full term development. This review outlines the nature of genomic reprogramming potential and its application, and suggests new approaches to avoid the ethical problems of creating embryos by nuclear transfer.
Collapse
Affiliation(s)
- Sayaka Wakayama
- Centre for Developmental Biology RIKEN Kobe, 2-2-3 Minatojima-minamimachi, Kobe 650-0047, Japan
| | | | | |
Collapse
|
14
|
Hornen N, Kues WA, Carnwath JW, Lucas-Hahn A, Petersen B, Hassel P, Niemann H. Production of Viable Pigs from Fetal Somatic Stem Cells. CLONING AND STEM CELLS 2007; 9:364-73. [PMID: 17907947 DOI: 10.1089/clo.2006.0009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Fetal somatic stem cells (FSSCs) are a novel type of somatic stem cells that have recently been discovered in primary fibroblast cultures from pigs and other species. The goal of the present study was to produce viable piglets from FSSCs. NT complexes were prepared from both FSSCs and porcine fetal fibroblasts (pFF) to permit comparison of these two donor cell types. FSSCs from isolated attached colonies were compared with pFF in their ability to form blastocysts upon use in NT. Fusion and cleavage rates were similar between the two groups, while blastocyst rates were significantly higher when using pFF as donor cells. FSSCs of three different size categories derived from dissociation of spheroids yielded similar results. The use of FSSCs of 15-20 microm in size yielded similar cleavage and blastocyst rates as fetal fibroblasts. In the final experiment NT complexes produced from FSSCs were transferred to foster mothers. After transfer to prepubertal gilts, three of seven recipients established pregnancies and delivered seven piglets, of which three piglets were viable and showed normal development. Results for the first time demonstrate that FSSCs are able to produce cloned embryos, and that pregnancies can be established and viable piglets can be produced.
Collapse
Affiliation(s)
- Nadine Hornen
- Department of Biotechnology, Institut für Tierzucht, Mariensee Neustadt, Germany
| | | | | | | | | | | | | |
Collapse
|
15
|
Eggan K. Dolly's Legacy: Human Nuclear Transplantation And Better Medicines for Our Children. CLONING AND STEM CELLS 2007; 9:21-5. [PMID: 17386009 DOI: 10.1089/clo.2006.0013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Kevin Eggan
- The Stowers Medical Institute, Harvard Stem Cell Institute and Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
| |
Collapse
|
16
|
Betthauser JM, Pfister-Genskow M, Xu H, Golueke PJ, Lacson JC, Koppang RW, Myers C, Liu B, Hoeschele I, Eilertsen KJ, Leno GH. Nucleoplasmin facilitates reprogramming and in vivo development of bovine nuclear transfer embryos. Mol Reprod Dev 2007; 73:977-86. [PMID: 16604516 DOI: 10.1002/mrd.20493] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Successful cloning by somatic cell nuclear transfer (NT) involves an oocyte-driven transition in gene expression from an inherited somatic pattern, to an embryonic form, during early development. This reprogramming of gene expression is thought to require the remodeling of somatic chromatin and as such, faulty and/or incomplete chromatin remodeling may contribute to the aberrant gene expression and abnormal development observed in NT embryos. We used a novel approach to supplement the oocyte with chromatin remodeling factors and determined the impact of these molecules on gene expression and development of bovine NT embryos. Nucleoplasmin (NPL) or polyglutamic acid (PGA) was injected into bovine oocytes at different concentrations, either before (pre-NT) or after (post-NT) NT. Pre-implantation embryos were then transferred to bovine recipients to assess in vivo development. Microinjection of remodeling factors resulted in apparent differences in the rate of blastocyst development and in pregnancy initiation rates in both NPL- and PGA-injected embryos, and these differences were dependent on factor concentration and/or the time of injection. Post-NT NPL-injected embryos that produced the highest rate of pregnancy also demonstrated differentially expressed genes relative to pre-NT NPL embryos and control NT embryos, both of which had lower pregnancy rates. Over 200 genes were upregulated following post-NT NPL injection. Several of these genes were previously shown to be downregulated in NT embryos when compared to bovine IVF embryos. These data suggest that addition of chromatin remodeling factors to the oocyte may improve development of NT embryos by facilitating reprogramming of the somatic nucleus.
Collapse
|
17
|
Wakayama T. Establishment of nuclear transfer embryonic stem cell lines from adult somatic cells by nuclear transfer and its application. ERNST SCHERING RESEARCH FOUNDATION WORKSHOP 2007:111-23. [PMID: 16903420 DOI: 10.1007/3-540-31437-7_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Nuclear transfer can be used to generate embryonic stem cell (ntESC) lines from a patient's own somatic cells. We have shown that ntESCs can be generated relatively easily from a variety of mouse genotypes and cell types of both sexes, even though it may be more difficult to generate clones directly. Several reports have already demonstrated that ntESCs can be used in regenerative medicine in order to rescue immunodeficient or infertile phenotypes. However, it is unclear whether ntES cells are identical to fertilized embryonic stem cells (ESCs). This review seeks to describe the phenotype and possible abnormalities of ntESC lines.
Collapse
Affiliation(s)
- T Wakayama
- Riken Center for Developmental Biology, Kobe, Japan.
| |
Collapse
|
18
|
Wakayama T. Production of Cloned Mice and ES Cells from Adult Somatic Cells by Nuclear Transfer: How to Improve Cloning Efficiency? J Reprod Dev 2007; 53:13-26. [PMID: 17332696 DOI: 10.1262/jrd.18120] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although it has now been 10 years since the first cloned mammals were generated from somatic cells using nuclear transfer (NT), most cloned embryos usually undergo developmental arrest prior to or soon after implantation, and the success rate for producing live offspring by cloning remains below 5%. The low success rate is believed to be associated with epigenetic errors, including abnormal DNA hypermethylation, but the mechanism of "reprogramming" is unclear. We have been able to develop a stable NT method in the mouse in which donor nuclei are directly injected into the oocyte using a piezo-actuated micromanipulator. Especially in the mouse, only a few laboratories can make clones from adult somatic cells, and cloned mice are never successfully produced from most mouse strains. However, this technique promises to be an important tool for future research in basic biology. For example, NT can be used to generate embryonic stem (NT-ES) cell lines from a patient's own somatic cells. We have shown that NT-ES cells are equivalent to ES cells derived from fertilized embryos and that they can be generated relatively easily from a variety of mouse genotypes and cell types of both sexes, even though it may be more difficult to generate clones directly. In general, NT-ES cell techniques are expected to be applied to regenerative medicine; however, this technique can also be applied to the preservation of genetic resources of mouse strain instead of embryos, oocytes and spermatozoa. This review describes how to improve cloning efficiency and NT-ES cell establishment and further applications.
Collapse
|
19
|
Bowles EJ, Campbell KHS, St John JC. Nuclear Transfer: Preservation of a Nuclear Genome at the Expense of Its Associated mtDNA Genome(s). Curr Top Dev Biol 2007; 77:251-90. [PMID: 17222707 DOI: 10.1016/s0070-2153(06)77010-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Nuclear transfer technology has uses across theoretical and applied applications, but advances are restricted by continued poor success rates and health problems associated with live offspring. Development of reconstructed embryos is dependent upon numerous interlinking factors relating both to the donor cell and the recipient oocyte. For example, abnormalities in gene expression following somatic cell nuclear transfer (SCNT) have been linked with an inability of the oocyte cytoplasm to sufficiently epigenetically reprogram the nucleus. Furthermore, influences on the propagation of mitochondria and mitochondrial DNA (mtDNA) could be of great importance in determining the early developmental potential of NT embryos and contributing to their genetic identity. mtDNA encodes some of the subunits of the electron transfer chain, responsible for cellular ATP production. The remaining subunits and those factors required for mtDNA replication, transcription and translation are encoded by the nucleus, necessitating precise intergenomic communication. Additionally, regulation of mtDNA copy number, via the processes of mtDNA transcription and replication, is essential for normal preimplantation embryo development and differentiation. Unimaternal transmission following natural fertilization usually results in the presence of a single identical population of mtDNA, homoplasmy. Heteroplasmy can result if mixed populations of mtDNA genomes co-exist. Many abnormalities observed in NT embryos, fetuses, and offspring may be caused by deficiencies in OXPHOS, perhaps resulting in part from heteroplasmic mtDNA populations. Additionally, incompatibilities between the somatic nucleus and the cytoplast may be exacerbated by increased genetic divergence between the two genomes. It is important to ensure that the nucleus is capable of sufficiently regulating mtDNA, requiring a level of compatibility between the two genomes, which may be a function of evolutionary distance. We suggest that abnormal expression of factors such as TFAM and POLG in NT embryos will prematurely drive mtDNA replication, hence impacting on early development.
Collapse
Affiliation(s)
- Emma J Bowles
- The Mitochondrial and Reproductive Genetics Group, The Division of Medical Sciences, The Medical School, The University of Birmingham, Birmingham B15 2TT, United Kingdom
| | | | | |
Collapse
|
20
|
Wakayama S, Jakt ML, Suzuki M, Araki R, Hikichi T, Kishigami S, Ohta H, Van Thuan N, Mizutani E, Sakaide Y, Senda S, Tanaka S, Okada M, Miyake M, Abe M, Nishikawa SI, Shiota K, Wakayama T. Equivalency of nuclear transfer-derived embryonic stem cells to those derived from fertilized mouse blastocysts. Stem Cells 2006; 24:2023-33. [PMID: 16690779 DOI: 10.1634/stemcells.2005-0537] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Therapeutic cloning, whereby nuclear transfer (NT) is used to generate embryonic stem cells (ESCs) from blastocysts, has been demonstrated successfully in mice and cattle. However, if NT-ESCs have abnormalities, such as those associated with the offspring produced by reproductive cloning, their scientific and medical utilities might prove limited. To evaluate the characteristics of NT-ESCs, we established more than 150 NT-ESC lines from adult somatic cells of several mouse strains. Here, we show that these NT-ESCs were able to differentiate into all functional embryonic tissues in vivo. Moreover, they were identical to blastocyst-derived ESCs in terms of their expression of pluripotency markers in the presence of tissue-dependent differentially DNA methylated regions, in DNA microarray profiles, and in high-coverage gene expression profiling. Importantly, the NT procedure did not cause irreversible damage to the nuclei. These similarities of NT-ESCs and ESCs indicate that murine therapeutic cloning by somatic cell NT can provide a reliable model for preclinical stem cell research.
Collapse
Affiliation(s)
- Sayaka Wakayama
- Laboratory for Genomic Programming, RIKEN Center for Developmental Biology, Kobe, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Abstract
Until recently, it was thought that only embryonic stem cells were pluripotent and that adult stem cells were restricted in their differentiative and regenerative potential to become the tissues in which they reside. However, the discovery that adult stem cells in one tissue can contribute to the formation of other tissues, especially after injury or cell damage, implies that stem cells have developmental plasticity. For example, haematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) from bone marrow can be used to regenerate diverse tissues at distant sites, including the lung. This article reviews the character of stem cells in the lung parenchyma and focuses on the potential uses of adult stem cells in research of lung injury and lung disease therapies.
Collapse
Affiliation(s)
- C C Yen
- Department of Life Sciences, National Chung Hsing University, and Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
| | | | | | | |
Collapse
|
22
|
Loi P, Clinton M, Vackova I, Fulka J, Feil R, Palmieri C, Della Salda L, Ptak G. Placental abnormalities associated with post-natal mortality in sheep somatic cell clones. Theriogenology 2006; 65:1110-21. [PMID: 16154189 DOI: 10.1016/j.theriogenology.2005.07.016] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2004] [Revised: 07/22/2005] [Accepted: 07/31/2005] [Indexed: 11/25/2022]
Abstract
We report on cloning experiments designed to explore the causes of peri- and post-natal mortality of cloned lambs. A total of 93 blastocysts obtained by nuclear transfer of somatic cells (granulosa cells) were transferred into 41 recipient ewes, and pregnancies were monitored by ultrasound scanning. In vitro derived, fertilized embryos (IVF, n=123) were also transferred to assess oocyte competence, and naturally mated ewes (n=120) were analysed as well. Cloned embryos developed to the blastocyst stage and implanted at the same rate as IVF embryos. After day 30 of gestation, however, dramatic losses occurred, and only 12 out of 93 (13%) clones reached full-term development, compared to 51 out of 123 (41.6%) lambs born from the IVF control embryos. Three full-term lamb clones were delivered stillborn, as a result of placental degeneration. A further five clone recipients developed hydroallantois. Their lambs died within 24h following delivery by caesarian section, and displayed degenerative lesions in liver and kidney resulting from the severe hydroallantois. One set of twins was delivered by assisted parturition at day 150, but died 24h later due to respiratory distress syndrome. The remaining two clone recipients underwent caesarian section, and the corresponding two lambs displayed signs of respiratory dysfunction and died at approximately 1 month of age due to a bacterial complication. Blood samples collected from the cloned lambs after birth revealed a wide range of abnormalities indicative of kidney and liver dysfunction. Macroscopical and histopathological examination of the placentae revealed a marked reduction in vascularization, particularly at the apex of the villous processes, as well as a loss of differentiation of the trophoblastic epithelium. Our results strongly suggest that post-mortality in cloned lambs is mainly caused by placental abnormalities.
Collapse
Affiliation(s)
- Pasqualino Loi
- Dipartimento di Scienze Biomediche Comparate, Teramo University, Piazza Aldo Moro 45, 64100 Teramo, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Kishigami S, Wakayama S, van Thuan N, Wakayama T. Cloned mice and embryonic stem cell establishment from adult somatic cell. Hum Cell 2006; 19:2-10. [PMID: 16643601 DOI: 10.1111/j.1749-0774.2005.00001.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cloning methods are now well described and becoming routine. Yet the frequency at which cloned offspring are produced remains below 2% irrespective of nucleus donor species or cell type. Especially in the mouse, few laboratories can make clones from adult somatic cells, and most mouse strains never succeed to produce cloned mice. On the other hand, nuclear transfer can be used to generate embryonic stem (ntES) cell lines from a patient's own somatic cells. We have shown that ntES cells can be generated relatively easily from a variety of mouse genotypes and cell types of both sexes, even though it may be more difficult to generate clones directly. Several reports have already demonstrated that ntES cells can be used in regenerative medicine in order to rescue immune deficient or infertile phenotypes. However, it is unclear whether ntES cells are identical to fertilized embryonic stem (ES) cells. In general, ntES cell techniques are expected to be applicable to regenerative medicine, however, these techniques can also be used for the preservation of the genetic resources of mouse strains instead of preserving such resources in embryos, oocytes or spermatozoa. This review seeks to describe the phenotype, application, and possible abnormalities of cloned mice and ntES cell lines.
Collapse
Affiliation(s)
- Satoshi Kishigami
- Center for Developmental Biology RIKEN, Kobe University, Kobe, Japan
| | | | | | | |
Collapse
|
24
|
Abstract
The full power of gene modification in higher eukaryotes, including its potential to correct disease-causing mutations, has so far been limited by its low efficiency. Now that power looks set to be released through the use of customized endonuclease "hands," DNA-binding zinc fingers linked to nuclease "thumbs," capable of grasping and cutting any chosen genomic target locus. Once cleaved, the target locus is efficiently repaired by endogenous mechanisms, using an exogenous DNA template that carries the chosen modification. These helping hands are likely to touch many areas of biological and clinical endeavor.
Collapse
Affiliation(s)
- Andrew C G Porter
- Gene Targeting Group, Department of Haematology, Imperial College Faculty of Medicine, Hammersmith Hospital, London, UK.
| |
Collapse
|
25
|
Del Vecchio F, Filareto A, Spitalieri P, Sangiuolo F, Novelli G. Cellular genetic therapy. Transplant Proc 2005; 37:2657-61. [PMID: 16182776 DOI: 10.1016/j.transproceed.2005.06.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Cellular genetic therapy is the ultimate frontier for those pathologies that are consequent to a specific nonfunctional cellular type. A viable cure for there kinds of diseases is the replacement of sick cells with healthy ones, which can be obtained from the same patient or a different donor. In fact, structures can be corrected and strengthened with the introduction of undifferentiated cells within specific target tissues, where they will specialize into the desired cellular types. Furthermore, consequent to the recent results obtained with the transdifferentiation experiments, a process that allows the in vitro differentiation of embryonic and adult stem cells, it has also became clear that many advantages may be obtained from the use of stem cells to produce drugs, vaccines, and therapeutic molecules. Since stem cells can sustain lineage potentials, the capacity for differentiation, and better tolerance for the introduction of exogenous genes, they are also considered as feasible therapeutic vehicles for gene therapy. In fact, it is strongly believed that the combination of cellular genetic and gene therapy approaches will definitely allow the development of new therapeutic strategies as well as the production of totipotent cell lines to be used as experimental models for the cure of genetic disorders.
Collapse
Affiliation(s)
- F Del Vecchio
- Dipartimento di Biopatologia e Diagnostica per Immagini, Sezione di Genetica, Universita' di Tor Vergata, Rome, Italy
| | | | | | | | | |
Collapse
|
26
|
Wakayama S, Kishigami S, Van Thuan N, Ohta H, Hikichi T, Mizutani E, Yanagimachi R, Wakayama T. Propagation of an infertile hermaphrodite mouse lacking germ cells by using nuclear transfer and embryonic stem cell technology. Proc Natl Acad Sci U S A 2005; 102:29-33. [PMID: 15618395 PMCID: PMC544064 DOI: 10.1073/pnas.0408548102] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Animals generated by systematic mutagenesis and routine breeding are often infertile because they lack germ cells, and maintenance of such lines of animals has been impossible. We found a hermaphrodite infertile mouse in our colony, a genetic male with an abnormal Y chromosome lacking developing germ cells. We tried to clone this mouse by conventional nuclear transfer but without success. ES cells produced from blastocysts, which had been cloned by using somatic cell nuclear transfer (ntES cells) from this mouse, were also unable to produce offspring when injected into enucleated oocytes. Although we were able to produce two chimeric offspring using these ntES cells by tetraploid complementation, they were infertile, because they also lacked developing germ cells. However, when such ntES cells were injected into normal diploid blastocysts, many chimeric offspring were produced. One such male offspring transmitted hermaphrodite mouse genes to fertile daughters via X chromosome-bearing sperm. Thus, ntES cells were used to propagate offspring from infertile mice lacking germ cells.
Collapse
Affiliation(s)
- Sayaka Wakayama
- Center for Developmental Biology, RIKEN Kobe, 2-2-3 Minatojima-minamimachi, Kobe 650-0047, Japan
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Wakayama S, Ohta H, Kishigami S, Thuan NV, Hikichi T, Mizutani E, Miyake M, Wakayama T. Establishment of male and female nuclear transfer embryonic stem cell lines from different mouse strains and tissues. Biol Reprod 2004; 72:932-6. [PMID: 15601921 DOI: 10.1095/biolreprod.104.035105] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Nuclear transfer can be used to generate embryonic stem cell lines from somatic cells, and these have great potential in regenerative medicine. However, it is still unclear whether any individual or cell type can be used to generate such lines. Here, we tested seven different male and female mouse genotypes and three cell types as sources of nuclei to determine the efficiency of establishing nuclear transfer embryonic stem cell lines. Lines were successfully established from all sources. Cumulus cell nuclei from F(1) mouse genotypes showed a significantly higher cumulative establishment rate from reconstructed oocytes than from other cells; however, there were no genotype differences in success rates from cloned blastocysts. Thus, the overall success depends on preimplantation development, and, once embryos have reached the blastocyst stage, the genotype differences disappear. All mouse genotypes that were tested demonstrated at least one cell line that subsequently contributed to germline transmission in chimeric mice, so these cell lines clearly possess the same potential as embryonic stem cells derived from fertilized embryos. Thus, nuclear transfer embryonic stem cells can be generated relatively easily from a variety of inbred mouse genotypes and cell types of both sexes, even though it may be more difficult to generate clones directly.
Collapse
Affiliation(s)
- Sayaka Wakayama
- Center for Developmental Biology, RIKEN Kobe, Kobe 650-0047, Japan
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Affiliation(s)
- Anthony C F Perry
- Laboratory of Mammalian Molecular Embryology, RIKEN Center for Developmental Biology, 2-2-3 Minatojima Minamimachi, Chuo-ku, Kobe 650-0047, Japan.
| |
Collapse
|
29
|
Abstract
Few treatment options are available for patients suffering from diseased and injured organs because of a severe shortage of donor organs available for transplantation. Therapeutic cloning, where the nucleus from a donor cell is transferred into an enucleated oocyte in order to extract pluripotent embryonic stem cells, offers a potentially limitless source of cells for replacement therapy. Scientists in the field of tissue engineering apply the principles of cell transplantation, material science, and engineering to construct biological substitutes that will restore and maintain normal function in diseased and injured tissues. The present chapter reviews recent advances that have occurred in therapeutic cloning and tissue engineering and describes applications of these new technologies that may offer novel therapies for patients with end-stage organ failure.
Collapse
Affiliation(s)
- Anthony Atala
- Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston Salem, North Carolina 27157, USA.
| | | |
Collapse
|
30
|
Human somatic cell nuclear transfer (cloning). Fertil Steril 2004; 82 Suppl 1:S236-9. [PMID: 15363739 DOI: 10.1016/j.fertnstert.2004.05.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2000] [Accepted: 08/08/2000] [Indexed: 10/25/2022]
|
31
|
de Grey ADNJ. Inter-Species Therapeutic Cloning: The Looming Problem of Mitochondrial DNA and Two Possible Solutions. Rejuvenation Res 2004; 7:95-8. [PMID: 15312296 DOI: 10.1089/1549168041553017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
32
|
Arat S, Rzucidlo SJ, Stice SL. Gene expression and in vitro development of inter-species nuclear transfer embryos. Mol Reprod Dev 2004; 66:334-42. [PMID: 14579409 DOI: 10.1002/mrd.10362] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This study examined the chromatin morphology, in vitro development, and expression of selected genes in cloned embryos produced by transfer of mouse embryonic fibroblasts (MEF) into the bovine ooplasm. After 6 hr of activation, inter-species nuclear transfer (NT) embryos (MEF-NT) had one (70%) or two pronuclei (20%), respectively. After 72 hr of culture in vitro, 62.6% of the MEF-NTs were arrested at the 8-cell stage, 31.2% reached the 2- to 4-cell stage, and only 6.2% had more than eight blastomeres, but none of these developed to the blastocyst stage. Whereas, 20% of NT embryos derived from bovine embryonic fibroblast fused with bovine ooplasm (BEF-NT) reached the blastocyst stage. Donor MEF nuclei expressing an Enhanced Green Fluorescent Protein (EGFP) transgene resulted in 1- to 8-cell stage MEF-NT that expressed EGFP. The expression of selected genes was examined in 8-cell MEF-NTs, 8-cell mouse embryos, enucleated bovine oocytes, and MEFs using RT-PCR. The mRNA for heat shock protein 70.1 (Hsp 70.1) gene was detected in MEF-NTs and MEF, but not in mouse embryos. The hydroxy-phosphoribosyl transferase (HPRT) mRNA was found in normal mouse embryos and MEF but not in MEF-NTs. Expression of Oct-4 and embryonic alkaline phospatase (eAP) genes was only detected in normal mouse embryos and not in the inter-species NT embryos. Abnormal gene expression profiles were associated with an arrest in the development at the 8-cell stage, but MEF-NT embryos appeared to have progressed through gross chromatin remodeling, typical of intra-species NT embryos. Therefore, molecular reprogramming rather than chromatin remodeling may be a better indicator of nuclear reprogramming in inter-species NT embryos.
Collapse
Affiliation(s)
- Sezen Arat
- Department of Animal and Dairy Science, University of Georgia, Athens, Georgia 30602, USA
| | | | | |
Collapse
|
33
|
de Grey ADNJ, Campbell FC, Dokal I, Fairbairn LJ, Graham GJ, Jahoda CAB, Porterg ACG. Total Deletion ofin VivoTelomere Elongation Capacity: An Ambitious but Possibly Ultimate Cure for All Age-Related Human Cancers. Ann N Y Acad Sci 2004; 1019:147-70. [PMID: 15247008 DOI: 10.1196/annals.1297.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Despite enormous effort, progress in reducing mortality from cancer remains modest. Can a true cancer "cure" ever be developed, given the vast versatility that tumors derive from their genomic instability? Here we consider the efficacy, feasibility, and safety of a therapy that, unlike any available or in development, could never be escaped by spontaneous changes of gene expression: the total elimination from the body of all genetic potential for telomere elongation, combined with stem cell therapies administered about once a decade to maintain proliferative tissues despite this handicap. We term this therapy WILT, for whole-body interdiction of lengthening of telomeres. We first argue that a whole-body gene-deletion approach, however bizarre it initially seems, is truly the only way to overcome the hypermutation that makes tumors so insidious. We then identify the key obstacles to developing such a therapy and conclude that, while some will probably be insurmountable for at least a decade, none is a clear-cut showstopper. Hence, given the absence of alternatives with comparable anticancer promise, we advocate working toward such a therapy.
Collapse
Affiliation(s)
- Aubrey D N J de Grey
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK.
| | | | | | | | | | | | | |
Collapse
|
34
|
Quivy V, Calomme C, Dekoninck A, Demonte D, Bex F, Lamsoul I, Vanhulle C, Burny A, Van Lint C. Gene Activation and Gene Silencing: A Subtle Equilibrium. CLONING AND STEM CELLS 2004; 6:140-9. [PMID: 15268788 DOI: 10.1089/1536230041372454] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The genetic make-up of a cell resides entirely in its DNA. Now that the nucleotide sequence of several genomes has been determined, the major challenging problem is to understand how cell differentiation, proliferation or death are controlled. Major steps include analysis of the determinants of the cell cycle, the unravelling of RNAs and proteins involved in the control of gene expression and the dissection of the protein-destruction machinery. The successive steps to be considered are transcription of RNA on the DNA template, mRNA stabilization or degradation, and mRNA translation and protein localization in the right cell compartment. Gene expression or gene silencing is the result of many DNA-RNA-protein interactions and chromatin is among the key regulators of gene expression. Open chromatin (euchromatin) allows expression of the DNA message. This chromatin structure is generally characterized by the presence on the gene promoters of transcription complexes associated with histone acetyltransferases (HATs). On the contrary, closed chromatin (heterochromatin) is poorly acetylated and more condensed. It contains histone deacetylases (HDACs), potentially associated with DNA methyltransferases (DNMTs). DNMT activity leads to methylation and silencing of the DNA. Thus, a major problem in the field of gene regulation resides in understanding chromatin structure at each promoter, a formidable task for the years to come.
Collapse
Affiliation(s)
- Vincent Quivy
- Université Libre de Bruxelles, Institut de Biologie et de Médecine Moléculaires, Service de Chimie Biologique, Laboratoire de Virologie Moléculaire, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Abstract
A severe shortage of donor organs available for transplantation in the United States leaves patients suffering from diseased and injured organs with few treatment options. Scientists in the field of tissue engineering apply the principles of cell transplantation, material science, and engineering to construct biological substitutes that will restore and maintain normal function in diseased and injured tissues. Therapeutic cloning, where the nucleus from a donor cell is transferred into an enucleated oocyte in order to extract pluripotent embryonic stem cells, offers a potentially limitless source of cells for tissue engineering applications. The present chapter reviews recent advances that have occurred in therapeutic cloning and tissue engineering and describes applications of these new technologies that may offer novel therapies for patients with end-stage organ failure.
Collapse
Affiliation(s)
- Chester J Koh
- Wake Forest Institute for Regenerative Medicine, Medical Center Boulevard, Winston Salem, NC 27157, USA
| | | |
Collapse
|
36
|
Peura TT. Improved in vitro development rates of sheep somatic nuclear transfer embryos by using a reverse-order zona-free cloning method. CLONING AND STEM CELLS 2003; 5:13-24. [PMID: 12713697 DOI: 10.1089/153623003321512120] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This paper describes a modified zona-free cloning protocol for examining the effects of short-term exposure of donor nuclei to maternal chromosomal components and associated factors. In vitro matured zona-free sheep oocytes were enucleated by micromanipulator-assisted aspiration either before or after fusion with adult fibroblast or granulosa donor cells. Subsequent kinetics of donor nuclei and maternal chromatin as well as in vitro embryo development rates were recorded. The effect of an additional activation stimulus in connection with the reverse-order cloning (fusion before enucleation) and the feasibility of manual enucleation by metal blade were also studied. As a result of the simultaneous fusion and activation, most donor nuclei remained in interphase but swelled in size. Maternal chromosomes reached anaphase II-telophase II stages within 1-2 h of activation, effectively facilitating telophase enucleation with both the micromanipulator-assisted aspiration and manual bisection. A significantly higher development rate to the blastocyst stage was achieved with the reverse-order protocol, suggesting further investigation into the possible role of oocyte nucleus-associated factors in reprogramming is warranted. Overall, the reverse-order zona-free cloning method was efficient in the production of transferable cloned sheep blastocysts and may offer yet another choice of methodology in the practical application of nuclear transfer technology.
Collapse
Affiliation(s)
- T T Peura
- South Australian Research and Development Institute, Turretfield Research Centre, Rosedale, Australia.
| |
Collapse
|
37
|
Oback B, Wiersema AT, Gaynor P, Laible G, Tucker FC, Oliver JE, Miller AL, Troskie HE, Wilson KL, Forsyth JT, Berg MC, Cockrem K, McMillan V, Tervit HR, Wells DN. Cloned cattle derived from a novel zona-free embryo reconstruction system. CLONING AND STEM CELLS 2003; 5:3-12. [PMID: 12713696 DOI: 10.1089/153623003321512111] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
As the demand for cloned embryos and offspring increases, the need arises for the development of nuclear transfer procedures that are improved in both efficiency and ease of operation. Here, we describe a novel zona-free cloning method that doubles the throughput in cloned bovine embryo production over current procedures and generates viable offspring with the same efficiency. Elements of the procedure include zona-free enucleation without a holding pipette, automated fusion of 5-10 oocyte-donor cell pairs and microdrop in vitro culture. Using this system, zona-free embryos were reconstructed from five independent primary cell lines and cultured either singularly (single-IVC) or as aggregates of three (triple-IVC). Blastocysts of transferable quality were obtained at similar rates from zona-free single-IVC, triple-IVC, and control zona-intact embryos (33%, 25%, and 29%, respectively). In a direct comparison, there was no significant difference in development to live calves at term between single-IVC, triple-IVC, and zona-intact embryos derived from the same adult fibroblast line (10%, 13%, and 15%, respectively). This zona-free cloning method could be straightforward for users of conventional cloning procedures to adopt and may prove a simple, fast, and efficient alternative for nuclear cloning of other species as well.
Collapse
Affiliation(s)
- B Oback
- Reproductive Technologies, AgResearch Ltd., Ruakura Research Centre, Hamilton, New Zealand.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Eggan K, Jaenisch R. Micromanipulating dosage compensation: understanding X-chromosome inactivation through nuclear transplantation. Semin Cell Dev Biol 2003; 14:349-58. [PMID: 15015742 DOI: 10.1016/j.semcdb.2003.09.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Nuclear transfer (NT) studies have provided insight into the functional importance of epigenetic alteration of the X chromosomes during X-inactivation. Uniparental embryos created by NT have been informative as to the time and location at which the imprint controlling extraembryonic X-inactivation is established. Experiments with female somatic cells, have demonstrated that the inactive X chromosome (Xi) is reactivated after NT, leading to random X-inactivation in the embryonic lineages of cloned embryos. However, in the extraembryonic lineages of clones, epigenetic information from the donor cell nucleus persists, leading to preferential inactivation of the donor cell's inactive X in the placenta of cloned animals. These results suggest epigenetic information established during embryonic X-inactivation is functionally equivalent to the gametic imprint.
Collapse
Affiliation(s)
- Kevin Eggan
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | | |
Collapse
|
39
|
Abstract
A commercially viable cattle embryo transfer (ET) industry was established in North America during the early 1970s, approximately 80 years after the first successful embryo transfer was reported in a mammal. Initially, techniques for recovering and transferring cattle embryos were exclusively surgical. However, by the late 1970s, most embryos were recovered and transferred nonsurgically. Successful cryopreservation of embryos was widespread by the early 1980s, followed by the introduction of embryo splitting, in vitro procedures, direct transfer of frozen embryos and sexing of embryos. The wide spread adoption of ethylene glycol as a cryoprotectant has simplified the thaw-transfer procedures for frozen embryos. The number of embryos recovered annually has not grown appreciably over the last 10 years in North America and Europe; however, there has been significant growth of commercial ET in South America. Within North America, ET activity has been relatively constant in Holstein cattle, whereas there has been a large ET increase in the Angus breed and a concomitant ET decrease in some other beef breeds. Although a number of new technologies have been adopted within the ET industry in the last decade, the basic procedure of superovulation of donor cattle has undergone little improvement over the last 20 years. The export-import of frozen cattle embryos has become a well-established industry, governed by specific health regulations. The international movement of embryos is subject to sudden and dramatic disturbances, as exemplified by the 2001 outbreak of foot and mouth disease in Great Britain. It is probable that there will be an increased influence of animal rights issues on the ET industry in the future. Several companies in North America are currently commercially producing cloned cattle. The sexing of bovine semen with the use of flow cytometry is extremely accurate and moderate pregnancy rates in heifers have been achieved in field trials, but sexed semen currently is available in only a few countries and on an extremely limited basis. As of yet, all programs involving the production of transgenic cattle are experimental in nature.
Collapse
Affiliation(s)
- John F Hasler
- Em Tran, Inc., 197 Bossler Road, Elizabethtown, PA 17022, USA.
| |
Collapse
|
40
|
Loi P, Fulka J, Ptak G. Amphibian and mammal somatic-cell cloning: different species, common results? Trends Biotechnol 2003; 21:471-3. [PMID: 14573358 DOI: 10.1016/j.tibtech.2003.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Since the production of Dolly the sheep cloning methods for somatic cells have been thoroughly described and are becoming routine. However, the rate at which live clones are produced remains low in all mammalian species tested so far. Remarkably, irrespective of the cloning protocol or the donor-cell type, all clones display common abnormalities, particularly in the placenta. The process is also complicated by early mortality of somatic-cell clones and the founder mammalian clone, Dolly the sheep, died in February 2003 aged six years. Based on published data and on our own experience, our view is that mammalian somatic-cell cloning and the pioneer nuclear-transfer data from amphibians have much in common. We suggest that the only way to improve nuclear reprogramming is to modify the chromatin structure of somatic cells before nuclear transfer, to provide the oocyte with a chromosomal structure that is more compatible with the natural reprogramming machinery of the oocyte.
Collapse
Affiliation(s)
- Pasqualino Loi
- Department of Comparative Biomedical Sciences, Teramo University, Teramo 64100, Italy.
| | | | | |
Collapse
|
41
|
Maga EA, Sargent RG, Zeng H, Pati S, Zarling DA, Oppenheim SM, Collette NMB, Moyer AL, Conrad-Brink JS, Rowe JD, BonDurant RH, Anderson GB, Murray JD. Increased efficiency of transgenic livestock production. Transgenic Res 2003; 12:485-96. [PMID: 12885169 DOI: 10.1023/a:1024257906647] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Production of transgenic livestock by pronuclear microinjection of DNA into fertilized zygotes suffers from the compounded inefficiencies of low embryo survival and low integration frequencies of the injected DNA into the genome. These inefficiencies are one of the major obstacles to the large-scale use of pronuclear microinjection techniques in livestock. We investigated exploiting the properties of recombinase proteins that allow them to bind DNA to generate transgenic animals via pronuclear microinjection. In theory, the use of recombinase proteins has the potential to generate transgenic animals with targeted changes, but in practice we found that the use of RecA recombinase-coated DNA increases the efficiency of transgenic livestock production. The use of RecA protein resulted in a significant increase in both embryo survival rates and transgene integration frequencies. Embryo survival rates were doubled in goats, and transgene integration was 11-fold higher in goats and three-fold higher in pigs when RecA protein-coated DNA was used compared with conventional DNA constructs without RecA protein coating. However, a large number of the transgenic founders generated with RecA protein-coated DNA were mosaic. The RecA protein coating of DNA is straightforward and can be applied to any species and any existing microinjection apparatus. These findings represent significant improvements on standard pronuclear microinjection methods by enabling the more efficient production of transgenic livestock.
Collapse
Affiliation(s)
- Elizabeth A Maga
- Department of Animal Science, University of California, Davis, CA 95616, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Abstract
Advances in cloning technology and successful cloning experiments in animals raised concerns about the possibility of human cloning in recent years. Despite many objections, this is not only a possibility but also a reality. Human cloning is a scientific revolution. However, it also introduces the potential for physical and psychosocial harm to human beings. From this point of view, it raises profound ethical, social and health related concerns. Human cloning would have an impact on the practice of nursing because it could result in the creation of new physiological and psychosocial conditions that would require nursing care. The nursing profession must therefore evaluate the ethics of human cloning, in particular the potential role of nurses. This article reviews the ethical considerations of reproductive human cloning, discusses the main reasons for concern, and reflects a nursing perspective regarding this issue.
Collapse
Affiliation(s)
- Leyla Dinç
- Hacettepe University School of Nursing, 06100 Ankara, Turkey.
| |
Collapse
|
43
|
Kues WA, Carnwath JW, Paul D, Niemann H. Cell cycle synchronization of porcine fetal fibroblasts by serum deprivation initiates a nonconventional form of apoptosis. CLONING AND STEM CELLS 2003; 4:231-43. [PMID: 12398804 DOI: 10.1089/15362300260339511] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The success of somatic nuclear transfer depends upon the cell cycle stage of the donor nucleus and the recipient cytoplast. Recently, we established efficient cell cycle synchronization protocols for porcine fetal fibroblasts and found that serum withdrawal leads to cell death. Here, we examined whether the specific cell death induced by serum deprivation follows the conventional apoptotic pathway in porcine fibroblasts. Terminal deoxynucleotidyl transferase mediated dUTP nick end-labeling analysis revealed that serum deprivation induced DNA fragmentation in a concentration and time dependent manner. Semiquantitative RT-PCR and Western blotting revealed activation of cell death-related genes Bak and Bax of the Bcl-2 family. However, electrophoretic analysis of genomic DNA from serum deprived cells did not provide evidence for the internucleosomal DNA cleavage which is characteristic of conventional apoptosis. Thus, serum deprivation triggers initial steps in the apoptotic pathway, but does not lead to the typical oligonucleosome-sized DNA ladder. These findings contribute to a better understanding of apoptotic pathways and aid to define essential parameters of the donor nucleus for successful somatic cloning.
Collapse
Affiliation(s)
- Wilfried A Kues
- Department of Biotechnology, Institute for Animal Science, Neustadt, Germany
| | | | | | | |
Collapse
|
44
|
Abstract
Despite the fact that cloned animals derived from somatic cells have been successfully generated in a variety of mammalian species, there are still many unsolved problems with current cloning technology. Somatic cell nuclear transfer has shown several developmental aberrancies, including a high rate of abortion during early gestation and increased perinatal death. One cause of these developmental failures of cloned embryos may reside in the epigenetic reprogramming of somatic donor genome. In mammals, DNA methylation is an essential process in the regulation of transcription during embryonic development and is generally associated with gene silencing. A genome-wide demethylation may be a prerequisite for the formation of pluripotent stem cells that are important for later development. We analyzed methylation patterns in cloned bovine embryos to monitor the epigenetic reprogramming process of donor genomic DNA. Aberrant methylation profiles of cloned bovine embryos were observed in various genomic regions, except in single-copy gene sequences. The overall genomic methylation status of cloned embryos was quite different from that of normal embryos produced in vitro or in vivo. These results suggest that the developmental failures of cloned embryos may be due to incomplete epigenetic reprogramming of donor genomic DNA. We expect that advances in understanding the molecular events for reprogramming of donor genome will contribute to clarify the developmental defects of cloned embryos.
Collapse
Affiliation(s)
- Y M Han
- Laboratory of Development and Differentiation, Korea Research Institute of Bioscience and Biotechnology, PO Box 115, Yusong, Daejeon 305-600, South Korea.
| | | | | | | |
Collapse
|
45
|
Abstract
The technique of nuclear transfer (NT) allows the production of embryos, fetuses, and offspring from a range of embryonic, fetal, and adult derived cell types in a range of species. Successful development is dependent upon numerous factors, including type of recipient cell, source of recipient cell, method of reconstruction, activation, embryo culture, donor cell type, and donor and recipient cell cycle stages. The present review will discuss the uses of NT, the techniques presently available, and the factors affecting subsequent development.
Collapse
Affiliation(s)
- K H Campbell
- School of Biosciences, University of Nottingham, Leicestershire, United Kingdom.
| | | | | | | |
Collapse
|
46
|
Abstract
Therapeutic human cloning has the potential significantly to reduce human suffering and enhance human happiness. This is the main ethical argument in its favour. The main ethical arguments against it centre on questions to do with the moral status of the human embryo. A subsidiary set of arguments arises from the connections between therapeutic human cloning and reproductive cloning. Most of the ethical questions concerning the status of the human embryo have long been examined in the context of abortion, though they are being re-examined in the context of genetic screening and embryo research. A consensus on such matters seems extremely unlikely to result in the near future. The current role of ethicists may not, therefore, be so much to attempt to produce a definitive answer to the question of the status of the human embryo at the very early developmental stages at which therapeutic human cloning would take place, but more to help clarify arguments and indicate the implications of particular approaches. That is what this paper seeks to do.
Collapse
Affiliation(s)
- Michael J Reiss
- Institute of Education, University of London, 20 Bedford Way, London, WC1H 0AL, UK.
| |
Collapse
|
47
|
Loi P, Clinton M, Barboni B, Fulka J, Cappai P, Feil R, Moor RM, Ptak G. Nuclei of nonviable ovine somatic cells develop into lambs after nuclear transplantation. Biol Reprod 2002; 67:126-32. [PMID: 12080008 DOI: 10.1095/biolreprod67.1.126] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Here we report on the successful reprogramming of nuclei from somatic cells rendered nonviable by heat treatment. Granulosa cells from adult sheep were heated to nonphysiological temperatures (55 degrees C or 75 degrees C) before their nuclei were injected into enucleated metaphase II oocytes. Reprogramming was demonstrated by the capacity of the reconstructed embryos to develop to the blastocyst stage in vitro and into fetuses and viable offspring in suitable foster mothers. To our knowledge, this is the first report of cloned mammalian offspring originating from nonviable cells. In addition, our experiments show that heat-treating donor nuclei destabilizes higher-order features of chromatin (but leaves intact its nucleosomal organization) and results in a high proportion of reconstructed embryos developing to the blastocyst stage and beyond.
Collapse
Affiliation(s)
- Pasqualino Loi
- Dipartimento di Strutture, Funzioni, Patologie e Biotecnologie, Università di Teramo, Piazza Aldo Moro 45, 64100 Teramo, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Lotem J, Sachs L. Cytokine control of developmental programs in normal hematopoiesis and leukemia. Oncogene 2002; 21:3284-94. [PMID: 12032770 DOI: 10.1038/sj.onc.1205319] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The establishment of a system for in vitro clonal development of hematopoietic cells made it possible to discover the cytokines that regulate hematopoiesis. These cytokines include colony stimulating factors and others, which interact in a network, and there is a cytokine cascade which couples growth and differentiation. A network allows considerable flexibility and a ready amplification of response to a particular stimulus. A network may also be necessary to stabilize the whole system. Cells called hematopoietic stem cells (HSC) can repopulate all hematopoietic lineages in lethally irradiated hosts, and under appropriate conditions give rise to neuronal, muscle, and epithelial cells. Granulocyte colony stimulating factor induces migration of both HSC and in vitro colony forming cells from the bone marrow to peripheral blood. Granulocyte colony stimulating factor is also used clinically to repair irradiation and chemotherapy associated suppression of normal hematopoiesis in cancer patients, and to stimulate normal granulocyte development in patients with infantile congenital agranulocytosis. It is suggested that there may also be appropriate conditions under which in vitro colony forming cells have a wider differentiation potential similar to that shown by HSC. An essential part of the developmental program is cytokine suppression of apoptosis by changing the balance in expression of apoptosis inducing and suppressing genes. Decreasing the level of cytokines that suppress therapeutic induction of apoptosis in malignant cells can improve cancer therapy. Cytokines and some other compounds can reprogram abnormal developmental programs in leukemia, so that the leukemic cells differentiate to mature non dividing cells, and this can also be used for therapy. There is considerable plasticity in the developmental programs of normal and malignant cells.
Collapse
Affiliation(s)
- Joseph Lotem
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | | |
Collapse
|
49
|
Abstract
Stem cells are a subject of immense research interest, and may in the not too far future provide the basis for a number of new therapies aimed at substituting damaged or lacking cells, tissues, and even organs. A number of stem cell types have been identified, including embryonal stem cells, umbilical cord blood stem cells, and bone marrow stem cells. Two of the most promising stem cell types, embryonal stem cells and umbilical cord blood stem cells, are obtained from sources within the field of gynecology and obstetrics, namely fertility clinics performing in-vitro fertilization, and labor wards, respectively. This review focuses on the biological potentials of stem cells with a primarily gynaecological-obstetrical perspective. It is not the aim of this review to discuss the many important ethical aspects of stem cell technologies.
Collapse
Affiliation(s)
- Kåre Rygaard
- The Fertility Clinic, Herlev Hospital, University of Copenhagen, Denmark.
| | | |
Collapse
|
50
|
Kang YK, Park JS, Koo DB, Choi YH, Kim SU, Lee KK, Han YM. Limited demethylation leaves mosaic-type methylation states in cloned bovine pre-implantation embryos. EMBO J 2002; 21:1092-100. [PMID: 11867537 PMCID: PMC125883 DOI: 10.1093/emboj/21.5.1092] [Citation(s) in RCA: 156] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cloning by nuclear transfer (NT) has been riddled with difficulties: most clones die before birth and survivors frequently display growth abnormalities. The cross-species similarity in abnormalities observed in cloned fetuses/animals leads us to suspect the fidelity of epigenetic reprogramming of the donor genome. Here, we found that single-copy sequences, unlike satellite sequences, are demethylated in pre-implantation NT embryos. The differential demethylation pattern between genomic sequences was confirmed by analyzing single blastocysts. It suggests selective demethylation of other developmentally important genes in NT embryos. We also observed a reverse relationship between methylation levels and inner cell mass versus trophectoderm (ICM/TE) ratios, which was found to be a result of another type of differential demethylation occurring in NT blastocysts where unequal methylation was maintained between ICM and TE regions. TE-localized methylation aberrancy suggests a widespread gene dysregulation in an extra-embryonic region, thereby resulting in placental dysfunction familiar to cloned fetuses/animals. These differential demethylations among genomic sequences and between differently allocated cells produce varied overall, but specified, methylation patterns, demonstrating that epigenetic reprogramming occurs in a limited fashion in NT embryos.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Yong-Mahn Han
- Animal Developmental Biotechnology Laboratory, Korea Research Institute of Bioscience and Biotechnology (KRIBB), PO Box 115, Yusong, Taejon 305-600, South Korea
Corresponding author e-mail address:
| |
Collapse
|