Somatic stem cells differ from embryonic stem ES cells in that Quizlet

Embryonic stem (ES) cells are intrinsically different from somatic cells in that they retain the capacity to differentiate into multiple cell types (1, 2). Maintenance of genomic stability in these cells is essential for their potential to serve as donor cells for tissue transplants Somatic stem cells differ from embryonic stem cells because under natural conditions, they give rise to just a ___ cell types few Somatic stem cells have the potential to trea Embryonic stem (ES) cells differ from somatic stem cells in that a) ES cells can only be derived from early embryos, whereas somatic stem cells are present in adults. b) ES cells retain the ability to renew themselves, whereas somatic stem cells do not. c) ES cells can differentiate into any cell type, whereas somatic stem cells are unipotent, and can produce only one differentiated cell type How is a somatic stem cell different from an embryonic stem cell? O Somatic stem cells can divide, but embryonic stem cells can't Somatic stem cells can't divide Somatic stem cells can differentiate into only a few cell types Somatic stem cells can give rise to any type of cell in the entire body O O

benign tumors that form upon injection of ES cells into immune deficient mice, can differentiate into tissues from all 3 embryonic layers Adult stem cells undifferentiated cells in a tissue, also in neonatal and embryonic tissues, aka tissue stem cells or somatic stem cells ES cells can only be derived from early embryos, whereas somatic stem cells are present in adults. b. ES cells retain the ability to renew themselves, whereas somatic stem cells do not. c. ES cells can differentiate into any cell type, whereas somatic stem cells are unipotent, and can produce only one differentiated cell type. d. A and c e. A,b. The key difference between embryonic and somatic stem cells is that the embryonic stem cells are pluripotent undifferentiated cells that have embryonic origin while somatic stem cells are multipotent undifferentiated cells that are of tissue and organ origin Embryonic stem cells (ES cells) are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage embryo. Human embryos reach the blastocyst stage 4-5 days post fertilization, at which time they consist of 50-150 cells. Somatic stem cells: Generate replacements for cells that are lost through normal wear and tear.

Individualized Therapy · Personal Service · State-of-the-Art Service

Somatic stem cells can only become a few types of cells whereas embryonic stem cells can become many types of differentiated cells. Where are somatic stem cells found in the body? Surrounded by niche class in the brain, blood, heart, teeth, liver. Is cell differentiation final and irreversible - embryonic stem cells: can differentiate into only body cells (pluripotent) differentiation in cells is due to difference gene expression in different cell types. All cells in a multicellular organism contain the same genes, but different cells will express different genes. outline the production of Dolly the Sheep using somatic cell. Embryonic stem cells (ESCs) are derived from the embryo and have the potential to become all the different cell types of the body (pluripotency). Somatic stem cells, sometimes called adult stem cells, are found in organs or tissues, can self-renew and yield the differentiated cell types comprising that organ or tissue (multipotency), and are.

Stem Cell Secretome at ANOVA - Stem Cell Treatmen

  1. The major difference between embryonic and somatic stem cells is that embryonic stem cells have the potential to differentiate into all cell types of the body, as they are pluripotent stem cells (cells that are able to differentiate into three primary germ cell layers of the early embryo and, thus, into any cell type of the body); whereas, it is believed that somatic stem cells can differentiate only into different cell types present in the tissue of their origin
  2. a) ES cells can only be derived from early embryos, whereas somatic stem cells are present in adults. b) ES cells retain the ability to renew themselves, whereas somatic stem cells do not. c) ES cells can differentiate into any cell type, whereas somatic stem cells are unipotent, and can produce only one differentiated cell type
  3. The main difference between embryonic and somatic stem cells is that the embryonic stem cells are pluripotent whereas the somatic stem cells are multipotent. That means; the embryonic stem cells can become all types of cells in the body while somatic stem cells can differentiate into several types of cells, but not all
  4. Extraordinary advances in pluripotent stem cell research have initiated an era of hope for regenerative strategies to treat human disease. Besides embryonic stem cells, the discovery of induced pluripotent stem cells widened the possibility of patient-specific cell therapy, drug discovery, and disease modeling
  5. Blastocyst-derived human ES cells differ somewhat from the stem cell lines derived from primordial germ cells by Shamblott and colleagues 17, which do not grow as flat monolayers, express the SSEA.

The key difference between adult and embryonic stem cells is that adult stem cells are multipotent while embryonic stem cells are pluripotent.. Stem cells are a category of cells with the ability to divide and develop into different types of cells in the body. They are distinguished from the normal cells since they divide and renew themselves over a longer period of time Tissue-specific stem cells Tissue-specific stem cells (also referred to as somatic or adult stem cells) are more specialized than embryonic stem cells. Typically, these stem cells can generate different cell types for the specific tissue or organ in which they live Induced pluripotent stem cells are stem cells that are created in the laboratory, a happy medium between adult stem cells and embryonic stem cells. iPSCs are created through the introduction of embryonic genes into a somatic cell (a skin cell for example) that cause it to revert back to a stem cell like state Somatic cells that have been reprogrammed to a pluripotent state, known as induced pluripotent stem (iPS) cells, are generating ex­citement due to their ability to function like embryonic stem (ES) cells. 1, 2 Unlike ES cells, iPS cells are more readily obtainable for ther­apy and research, and their isolation does not carry the same ethical concerns. 1, 2 Human iPS cells may be an ideal source for patient-specific therapy since they can be derived from the patients themselves

GJIC has been implicated in regulating different biological events in many stem cells, including cell proliferation, differentiation and apoptosis. This review summarizes the current understanding of gap junctions in both embryonic and somatic stem cells, as well as their potential role in growth control and cellular differentiation Limitations: Somatic stem cells can become only a subset of related cell types which makes their use for potential therapies limited. They also are in very small number and are hard to isolate and grow in culture. These cells require immune suppressive drugs when used. Considerations: This type of therapy is not considered controversial Embryonic stem (ES) cells are formed as a normal part of. EMBRYONIC AND SOMATIC STEM CELLS. After fertilization, the zygote divides to form the morula and then the blastocyst. The blastocyst consists of an outer layer of cells, called the trophoblast, an inner cavity of fluid, called the blastocele, and an internal cluster of cells, called the inner cell mass (ICM) (Rossant 2008).The embryo forms from the cells of the ICM, and these cells can be. Induced stem cells (iSC) are stem cells derived from somatic, reproductive, pluripotent or other cell types by deliberate epigenetic reprogramming. 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. Stem cells give rise to various kinds of cells in the body. Totipotent stem cells are embryonic stem cells that are present during the first few cell divisions postfertilization and can form any of the different types of cells in the body. Multipotent stem cells are adult stem cells that can form other cell types, but have limited potency

Embryonic stem cells and somatic cells differ in mutation

An Argument against a Role for Oct4 in Somatic Stem Cells. Reports of Oct4 expression in somatic and cancer cells have suggested that Oct4 could regulate self-renewal in somatic stem cells as it does in embryonic stem cells. In this issue of Cell Stem Cell, Lengner et al. (2007) provide compelling evidence that Oct4 is neither expressed in nor. While cultured embryonic stem (ES) cells can be harvested in abundance and appear to be the most versatile of cells for regenerative medicine, adult stem cells also hold promise, but the identity and subsequent isolation of these comparatively rare cells remains problematic in most tissues, perhaps with the notable exception of the bone marrow Mouse embryonic stem (ES) cells, derived from the inner cell mass (ICM) of day 3.5 blastocysts, are capable of differentiating into all cells of the embryo proper. ES cell pluripotency is conferred in part through the expression of core transcription factors Oct4, Sox2, and Nanog [1, 2]. In mouse and human ES There are three types of stem cells: adult stem cells, embryonic (or pluripotent) stem cells, and induced pluripotent stem cells (iPSCs). Adult/Tissue Stem Cells Adult stem cells, or tissue stem cells, can come from different parts of the adult body. They are specific to a certain kind of tissue in the body: for instance, liver [

15.4. Stem Cells Stem cells are cells that divide by mitosis to form either two stem cells, thus increasing the size of the stem cell pool, or one daughter that goes on to differentiate, and one daughter that retains its stem-cell properties. How the choice is made is still unknown Embryonic Stem Cells (ESCs) are commonly derived from the inner cell mass (ICM) of a blastocyst, an early (4 5 days) stage of the embryo. Embryonic germ cells (EGCs) are isolated from the gonadal ridge of a 5 10 week foetus. Adult stem cells differ from ESCs and EGCs in that they are fou nd in tissues after birth, an Stem cells are primary cells that can self-repair by division, and differentiate into many specialized cell types. Depending on the source of origin, there are two types: embryonic and adult stem cells. Embryonic stem cells originate from epiblast tissue (blastocyst cell mass). A blastocyst is an early embryo (approximately 5-day-old human embryo) that contains 50 to 150 cells An embryonic stem cell chromatin remodeling complex, esBAF, is essential for embryonic stem cell self-renewal and pluripotency. Proc Natl Acad Sci USA 2009; 106 :5181-5186. CAS PubMed Google Schola Embryonic stem (ES) cells are a collection of cells found only in very early development which are the precursors to every cell type in the human body. The vast majority of cells in the body (somatic cells) fall into specific classes or types, such as muscle, bone and neurons, each of which have unique characteristics and functions

Stem Cells Questions and Study Guide Quizlet Flashcards

Fusion of Somatic Cells and Embryonic Stem Cells Epigenetic reprogramming of somatic nuclei to an undifferenti-ated state has been demonstrated in murine hybrids produced byfusion ofembryoniccells withsomatic cells.Hybrids between various somatic cells and embryonic carcinoma cells (Solter, 2006), embryonic germ (EG), or ES cells (Zwaka and. Somatic cells can be dedifferentiated in vitro by fusion with pluripotent cells, activating genes that are not expressed in adult stem cells [4 - 7]. For example, the fusion of a thymic lymphocyte with an embryonic germ cell or an embryonic stem cell (ESC) has led to the activation of the Oct4 gene in the somatic Embryonic stem cells retain the ability of the inner cell mass of blastocysts to differentiate into all cell types of the body and have acquired in culture unlimited self-renewal capacity. Somatic stem cells are found in many adult tissues, have an extensive but finite lifespan and can differentiate into a more restricted array of cell types The successful cultivation of ICM cells and establishment of permanent lines of pluripotent embryonic stem cells from early embryos, the embryonic stem (ES) cell lines, was a breakthrough for cell and developmental biologists in the early 1980s (Evans and Kaufman, 1981, Martin, 1981).Later on, pluripotent embryonic germ (EG) cell lines have been established from primordial germ cells (Stewart. Stem Cells vs. Mature Cells: There are three things that make stem cells different from regular somatic cells. They are able to replicate (divide) for long periods of time, they are able to turn into specialized cells ( NIH, 2009 ) such as cells of the muscle tissue, brain, liver and heart ( Klug, 2012 ) and they are unspecialized

1.Somatic stem cells in the epithelial lining of the intestie. a)are particular abundant at the tips of the villi, to be better positioned to replace damaged cells. b)are found deep in the crypts between the intestinal villi. c)are evenly distributed throughout the epithelial layer. d)are terminally differentiated, thus more likely to become. Different Types of Stem Cells Embryonic stem cells (ES)refer to the cells of the inner cell mass of the blastocyst dur-ing embryonic development. ES are partic-ularly notable for their two fundamental properties: the capacity to differentiate into any cell type in the body and the ability to self replicate for numerous generations (Lyons and. Embryonic stem (ES) cells can differentiate into a much wider variety of cell types than somatic stem cells. They are believed to have the capacity (at least in theory) to develop into the full range of cells that make up the human body, including cardiac muscle cells, nerve cells, liver cells, and blood cells

Embryonic stem ES cells differ from somatic stem cells in

Mouse embryonic stem cells. The most-studied embryonic stem cells are mouse embryonic stem cells, which were first reported in 1981. This type of stem cell can be cultured indefinitely in the presence of leukemia inhibitory factor (LIF), a glycoprotein cytokine.If cultured mouse embryonic stem cells are injected into an early mouse embryo at the blastocyst stage, they will become integrated. In the context of generating patient-specific pluripotent stem cells, reproducible results with various patient-derived somatic cells and with different egg donors are a necessity. Figure S1 Development of Human SCNT Embryos and Derivation of NT-ESCs with or without Caffeine Treatment Using Oocytes from Egg Donor A, Related to Figure somatic cell nuclear isolation and injection into an enucleated oocyte are demonstrated. Once a blastocyst is created, it can be used for either distinct process. Rag2 +/+ Corrected Rag2 -/- Deficient Isolate Postmitotic Somatic Cells 1. Nuclear Transfer 2. Isolate Isogenic 3. Create Blastocyst Embryonic Stem Cells 4. Homologous. In the blood system, there is now definitive evidence that the somatic-, blood-specific stem cells are originated during embryonic life and maintained thereafter. Although Notch is generally considered as an essential signaling pathway that regulates multiple stem cell functions, its participation diverges among the different organs and tissues

Yu et al., 2007. Induced pluripotent stem cell lines derived from human somatic cells. Science. 318, 1917-20. Abstract » Byrne et al., 2007. Producing primate embryonic stem cells by somatic cell nuclear transfer. Nature. 450, 497-502. Abstract » Wernig, M., et al., 2007. In vitro reprogramming of fibroblasts into a pluripotent ES-cell-like. In addition to adult tissue stem cells, stem cells can be isolated from pre-implantation mouse and human embryos and maintained in culture as undifferentiated cells (figure 1). Such embryonic stem (ES) cells have the ability to generate all the differentiated cells of the adult and are thus described as being pluripotent (figure 1)

Human cells come in a variety of types, such as adult stem cells, somatic cells, and the more conventional embryonic stem (ES) cells. These cells can potentially be used to regenerate human cells, organs, and tissues and contribute toward restoration of normal function after disease or injury [2]. The Russian histologist Alexander A. Maximov. Somatic stem cells are capable of both self-renewal and differentiation into at least one mature cell type and have been identified in a diverse range of tissues and organs, including, but not limited to, hematopoietic stem cells (HSCs) in the bone marrow, muscle stem cells (MuSCs) in skeletal muscle, intestinal stem cells in the gut, and the. 2. Embryonic Stem Cells. Embryonic stem cell lines (ES cell lines) are cultures of cells derived from the epiblast tissue of the inner cell mass (ICM) of a blastocyst or earlier morula stage embryos. A blastocyst is an early stage embryo—approximately four to five days old in humans and consisting of 50-150 cells

Solved: How Is A Somatic Stem Cell Different From An Embry

Reports of Oct4 expression in somatic and cancer cells have suggested that Oct4 could regulate self-renewal in somatic stem cells as it does in embryonic stem cells. In this issue of Cell Stem Cell, Lengner et al. (2007) provide compelling evidence that Oct4 is neither expressed in nor required for somatic stem cell function properties of making stem cells to differ from other cells in the body. The establishment of the first embryonic stem (ES) cells in mice, but nowadays stem cells have been the focus of active research because of their enormous future for basic research, medicine and animal biotechnology. Work with fish stem cell culture has skilled 20 years Accumulating somatic mutations have been implicated in age-related cellular degeneration and death. Because of their random nature and low abundance, somatic mutations are difficult to detect except in single cells or clonal cell lineages. Here, we show that in single hepatocytes from human liver, an organ exposed to high levels of genotoxic stress, somatic mutation frequencies are high and.

Somatic cell reprogramming holds great promise for the development of novel cellular therapeutics. A number of sources of reprogramming potential have been identified, including oocytes, embryonic germ (EG) cells and embryonic stem (ES) cells In this issue of Cell Stem Cell, Pan et al. (2007) and Zhao et al. (2007) report genome-wide histone H3 trimethylations at lysines 4 and 27 in human embryonic stem (ES) cells.Similar gene sets arise via different experimental systems, advancing our understanding of stem cell epigenetics

embryonic and adult stem cells Flashcards Quizle

adult (somatic) stem cells and embryonic stem (ES) cells. The recent derivation of human ES cell lines from human blasto-cysts1,2 and human embryonic germ (EG) cell lines from primordial germ cells3 has aroused intense public and scien-tific discussion. This interest stems in part from the contro Embryonic stem cells. Embryonic stem cells are the cells within the protective layer of the blastocyst. They are pluripotent, which means they can develop into any of the cells of the adult body. Researchers believe that, because they are pluripotent, and easy to grow, they have the best potential for replacing damaged or lost tissue or body parts Stem cell - Stem cell - Adult stem cells: Some tissues in the adult body, such as the epidermis of the skin, the lining of the small intestine, and bone marrow, undergo continuous cellular turnover. They contain stem cells, which persist indefinitely, and a much larger number of transit amplifying cells, which arise from the stem cells and divide a finite number of times until they.

5. Somatic Cell Nuclear Transfer (SCNT) - Therapeutic Cloning 1.Nucleus of oocyte is removed and replaced with foreign nucleus from any somatic cell that is 'reprogrammed' in the environment of the egg. 2.Artificial activation of egg and 5-7 days in culture allows development of ES cell-like, SCNT pluripotent stem-cell line Cell Stem Cell Article Oct4 Expression Is Not Required for Mouse Somatic Stem Cell Self-Renewal Christopher J. Lengner,1 Fernando D. Camargo,1 Konrad Hochedlinger,3 G. Grant Welstead,1 Samir Zaidi,2 Sumita Gokhale,1 Hans R. Scholer,4 Alexey Tomilin,5 and Rudolf Jaenisch1 ,2 * 1Whitehead Institute for Biomedical Research 2Department of Biology Massachusetts Institute of Technology, 9 Cambridge. EMBRYONIC STEM CELLS/INDUCED PLURIPOTENT STEM CELLS Distinguishing Between Mouse and Human Pluripotent Stem Cell Regulation: The Best Laid Plans of Mice and Men ANGELIQUE SCHNERCH, a,b CHANTAL CERDAN,a MICKIE BHATIA a,b aStem Cell and Cancer Research Institute, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada; bDepartment of Biochemistry and Biomedical Sciences. Embryonic stem (ES) cells are derived from the inner cell mass of the embryonic blastocyst. ES cells were first isolated and characterized in mice1 and subsequently in humans2,3,4. ES cells can differentiate into cells from all three germ layers and give rise to most cell types5. The pluripotency of stem cells is controlle Stem cells and Genesis. by Jonathan Sarfati [2001; Updated from time to time with new research information; last update 21 November 2017] Editor: We are re-posting this 2001 Journal article on the front page, because it is an overview of what has been a very controversial issue. The basic biblically-based moral principles have not changed, of course: that is: research that destroys embryos is.

For more on this, google induced pluripotent stem cells. It's pretty neat. There are major limitations to both of these that researchers are still trying to overcome. One of the biggest is the telomere shortening problem, but there is also a lot of potential with these techniques different types of stem cells come from, what their potential is for use in therapy, and why some types of stem cells are shrouded in controversy. Researchers are working on new ways to use stem cells to cure diseases and heal injuries. Learn more about unlocking stem cell potential. Embryonic Stem Cells Embryonic stem (ES) cells are formed as.

Cell Stem Cell Review Unraveling Epigenetic Regulation in Embryonic Stem Cells Marina Bibikova,1 Louise C. Laurent,2,3 Bing Ren,4,5 Jeanne F. Loring,2,* and Jian-Bing Fan1,* 1Illumina, Inc., San Diego, CA 92121, USA 2Center for Regenerative Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA 3Department of Reproductive Medicine 4Ludwig Institute for Cancer Researc Promising results with stem cell transplantation at ANOVA IRM. Talk to an expert. The most potent stem cell treatment to date.Talk to an expert at ANOVA IRM How do somatic stem cells differ from embryonic stem cells? Tissue Membranes A tissue membrane is a thin layer or sheet of cells that covers the outside of the body (for example, skin), the organs (for example, pericardium), internal passageways that lead to the exterior of the body (for example, abdominal mesenteries), and the lining of the. Embryonic Stem Cell Advantages 1. Flexible—appear to have the potential to make any cell 2. Immortal—one ES cell line can potentially provide an endless supply of cells with defined characteristics 3. Availability—embryos from in vitro fertilization clinics Embryonic Stem Cell Disadvantages 1 Adult versus Embryonic Stem Cells. Dr. Mae-Wan Ho gives the latest score-sheet in the great stem cell debate. In June, the journal Nature published two articles online, one describing the use of embryonic stem (ES) cells to reverse the symptoms of Parkinson's disease [1], the other, the isolation of adult stems cells from bone marrow that can.

A b and c 9 Embryonic stem ES cells differ from somatic

  1. In adults, stem cells (often referred to as adult stem cells or somatic stem cells) with a more restricted capacity to generate different cell types have been identified in many tissues. Somatic stem cells for the most part reside in special microenvironments called niches, composed of mesenchymal, endothelial, and other cell types
  2. Key Difference - IPS Cells vs Embryonic Stem Cells There are several types of stem cells which can be used for tissue regeneration in tissue engineering and wound healing. Among them, embryonic stem cells serve as a major and the most suitable stem cell types since they are naturally pluripotent
  3. With their properties of self-renewal and differentiation, embryonic stem (ES) cells hold great promises for regenerative therapy. However, teratoma formation and ethical concerns of ES cells may restrict their potential clinical applications. Currently, parthenogenetic embryonic stem (pES) cells have attracted the interest of researchers for its self-renewing and pluripotent differentiation.
  4. cells, referred to as embryonic stem (ES) cells, can be derived from it. Embryonic stem cells derived from the mouse have the innate capacity (potential) to differentiate into each of the 200 or so cell types which make up the body, and are described as pluripotent (see also glossary of terms)

Adult stem cells. Adult or somatic stem cells exist throughout the body after embryonic development and are found inside of different types of tissue. Adult stem calls are found in many organs and tissues in the human body, including the dental pulp contained within teeth. Embryonic stem cells. Embryonic stem cells are derived from a four- or. Q. stem cells are defined as. answer choices. a cell that has the ability to divide only once and stay the same as other kinds of cells. A cell that has the ability to continuously divide and differentiate into various other kinds of cells/tissues. any cell of a living organism other than the reproductive cells An embryonic stem cell would be a typical example of a pluripotent cell, although considering several recent descriptions of cells that have a similar potency but are derived from various fetal. References. Stem cells are found and originate in the early stages of embryonic growth, as part of the embryo, placenta or umbilical cord, known as embryonic stem cells. Adult stem cells are cells found in adult somatic tissues, dividing when prompted by damage. Placental or umbilical cord cells are located in the placenta and are harvested.

We started three different approaches for establishment of the in vitro gametogenesis systems: 1) ES-derived gametogenesis, 2) derivation of germ cells from somatic stem cells and 3) in vitro. Stem cells are gaining attention as promising tools in the field of regenerative medicine and developmental biology especially after the establishment of human embryonic stem (ES) cells in 1998 and human induced pluripotens stem (iPS) cells in 2007 . Human iPS cells are considered to possess similar characteristics to human ES cells . Because. Currently, the main stem cell therapies under consideration are divided into two types: those using embryonic stem cells ('ES cells') and those using somatic stem cells. Although ES cells are currently in vogue, unresolved ethical issues and problems of rejection and canceration remain major hurdles to their clinical use Stem cells are quickly coming into focus of much biomedical research eventually aiming at the therapeutic applications for various disorders and trauma. It is important, however, to keep in mind.

IJMS | Free Full-Text | BC-Box Motif-Mediated NeuronalSomatic CellsMale and female germline and somatic stem cells in theirRBCP - Stem cell perspectives in Plastic Surgery

The richest source of embryonic stem cells is tissue formed during the first five days after the egg has started to divide. At this stage of development, called the blastocyst, the embryo consists of a cluster of about 100 cells that can become any cell type. Stem cells are harvested from cloned embryos at this stage of development, resulting. Induced pluripotent stem cell (iPS cell), immature cell that is generated from an adult (mature) cell and that has regained the capacity to differentiate into any type of cell in the body. Induced pluripotent stem cells (iPS cells) differ from embryonic stem cells (ES cells), which form the inner cell mass of an embryo but also are pluripotent, eventually giving rise to all the cell types that. Embryonic Stem (ES) Cells : Because ES cells are pleuripotent , they can potentially give rise to the variety of cell types that are instrumental in regenerating damaged myocardium , including cardiomyocytes , endothelial cells and smooth muscle cells . To this end , mouse and human ES cells have been shown to differentiate to form endothelial and smooth muscle cells in vitro and in vivo, and. embryonic stem cells. (2, 3, 4) The ultimate test for pluripotency has been the ability of mouse-cultured embryonic stem cells to contribute to chimeric (an individual, organ, or part consisting of tissues of diverse genetic constitution) tissues of the embryo after introduction of embryonic stem cells from severa