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Introduction to Biotechnology
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2020
Another application of animal biotechnology is the use of somatic cell nuclear transfer to produce genetically identical copies of an organism. This process has been referred to as cloning. To date, somatic cell nuclear transfer has been used to clone cattle, sheep, pigs, goats, horses, mules, cats, rats, and mice. The technique involves culturing somatic cells from an appropriate tissue (fibroblasts) from the animal to be cloned. Nuclei from the cultured somatic cells are then microinjected into an enucleated oocyte obtained from another individual of the same or a closely related species. Through a process that is not yet understood, the nucleus from the somatic cell is reprogrammed to a pattern of gene expression suitable for directing normal development of the embryo. The embryo is further cultured in an in vitro environment, and then it is transferred to a recipient female for normal fetal development (Figure 1.4). Another very important application of genetically modified animals is in the drug testing and toxicity evaluations. In Chapter 7, we have discussed various applications of animal biotechnology with great details supported by beautiful illustrations.
Introduction to Biotechnology
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2018
Another application of animal biotechnology is the use of somatic cell nuclear transfer to produce genetically identical copies of an organism. This process has been referred to as cloning. To date, somatic cell nuclear transfer has been used to clone cattle, sheep, pigs, goats, horses, mules, cats, rats, and mice. The technique involves culturing somatic cells from an appropriate tissue (fibroblasts) from the animal to be cloned. Nuclei from the cultured somatic cells are then microinjected into an enucleated oocyte obtained from another individual of the same or a closely related species. Through a process that is not yet understood, the nucleus from the somatic cell is reprogrammed to a pattern of gene expression suitable for directing normal development of the embryo. The embryo is further cultured in an in vitro environment, and then it is transferred to a recipient female for normal fetal development (Figure 1.2).
Overview of Recent Trends in Stem Cell Bioprocessing
Published in V. Sivasubramanian, Bioprocess Engineering for a Green Environment, 2018
M. Jerold, V. Sivasubramanian, K. Vasantharaj, C. Vigneshwaran
There are mainly two types of stem cells: pluripotent stem cells (PSCs) and adult stem cells. PSCs include embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). The ESCs produced from the inner cell mass of the blastocyst tend to differentiate into various forms of cell types (Thomson et al., 1998). In various cases, the somatic cells are reprogrammed using pluripotent genes, are allowed to retrieve the properties of pluripotent cells (Takahashi et al., 2007; Yu et al., 2007) and are referred to as iPSCs. Further, the adult stem cells are categorized into three forms: hematopoietic stem cells (HSCs), mesenchymal stem cells (MSCs), and neural stem cells (NSCs). Adult stem cells are not preferred due to inadequate proliferation and differentiation potential. Somatic cells produced from fetal tissue sources such as amniotic fluid stem cells are widely used in cell therapy, tissue engineering, drug discovery, and disease modelling due to their massive proliferation and differentiation ability (Trohatou et al., 2013).
Posthumanism: Creation of ‘New Men’ Through Technological Innovation
Published in The New Bioethics, 2021
Genome editing is intended to alter the biophysical characteristics (phenotype) by introducing changes in the DNA sequence (genotype); genome changes are effected by inserting, deleting, modifying or replacing specific DNA segments of the genome either in somatic or germline cells. Clinical applications of genetic changes to somatic cells to treat cancer and prevent monogenic human diseases have been used during the past several decades. Although considerable progress has been achieved in the last years in genome editing and a small number of clinical trials are under way (Ishii 2016) only a few have been approved as therapies (Reeves 2016). Currently, the great interest in this therapeutic approach is reflected in the programme Somatic Cell Genome Editing launched by National Institutes of Health to accelerate the development safer and more effective genome-editing tools (Perry et al. 2018).
Dental pulp stem cells in serum-free medium for regenerative medicine
Published in Journal of the Royal Society of New Zealand, 2020
Dawn E. Coates, Mohammad Alansary, Lara Friedlander, Diogo G. Zanicotti, Warwick J. Duncan
The retention of stemness in culture is an essential requirement for evaluating and enabling clinical translation. Interestingly, there is evidence that the culture of DPSCs in low or serum-free conditions markedly increases the levels of p75 and HNK-1. These known markers of neural crest cells increased from 2% of cells in 10% serum to 34–58% of cells in low/serum-free conditions (Gazarian and Ramírez-García 2017). It is thus possible that serum-free medium is beneficial for retaining the stemness of DPSCs. The role of Oct3/4, Sox2, cMyc and Klf4 in the production of induced pluripotent stem cells (iPSC) from somatic cells is well accepted (Takahashi and Yamanaka 2006). That neural crest stem cells can be stimulated to become iPSC with only the addition of Oct3/4 and either Klf4 or cMyc indicates their more embryonic nature (Kim et al. 2008). There is therefore good evidence that a population of neural crest derived stem cells can be found within dental pulp and that serum-free medium may enhance their stemness.
Down-regulation of pluripotency and expression of SSEA-3 surface marker for mesenchymal Muse cells by in vitro expansion passaging
Published in Egyptian Journal of Basic and Applied Sciences, 2019
Ali M. Fouad, Mahmoud M. Gabr, Elsayed K. Abdelhady, Sahar A. Rashed, Sherry M. Khater, Mahmoud M. Zakaria
Stem cells can be divided as embryonic and non-embryonic stem cells. Embryonic stem cells are the gold standard for pluripotent stem cells which can differentiate into the three germ layers (ectoderm, endoderm and mesoderm). In the developing embryo, pluripotent stem cells are the origin of somatic and germline cells [1]. Adult stem cells as embryonic stem cells are all undifferentiated cells. However, the differentiation capacity of adult stem cells is limited to its origin. Hematopoietic and mesenchymal stem cells are the main identified types of adult stem cells, hematopoietic stem cells can be obtained from bone marrow, umbilical cord blood, and peripheral blood and are capable of generating all cell lineage found in mature blood [2]. While mesenchymal stem cells, in the suitable environment have the ability to differentiate into chondrocytes, adipocytes and osteocytes [3], and can be obtained from bone marrow as a primary source, fat tissue and umbilical cord [4]. In 2006, a scientific breakthrough was performed by Yamanaka and colleagues after generating pluripotent stem cells from somatic cells by genetic manipulation with pluripotent markers, these cells are called induced pluripotent stem cells (iPSCs) [5].