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Genetic Update Conferences 2012-2013. Reprogramming = Dedifferentiation - the process of converting somatic cell back in to pluripotent stems. Vocabulary.
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Genetic Update Conferences 2012-2013 Reprogramming = Dedifferentiation - the process of converting somatic cell back in to pluripotent stems.
Regression of a specialized cell or tissue to a simpler, more embryonic, unspecialized form. Dedifferentiation may occur before the regeneration of appendages in plants and certain animals and in the development of some cancers Dedifferentiation
oocyte cytoplasm • is a female gametocyte or germ cell involved in reproduction. In other words, it is an immature ovum, or egg cell. An oocyte is produced in the ovary during female gametogenesis. The female germ cells produce a primordial germ cell (PGC) which undergoes mitosis to form an oogonium. During oogenesis the oogonium becomes a primary oocyte.
pluripotent • In cell biology, pluripotency refers to a stem cell that has the potential to differentiate into any of the three germ layers: endoderm (interior stomach lining, gastrointestinal tract, the lungs), mesoderm (muscle, bone, blood, urogenital), or ectoderm (epidermal tissues and nervous system).Pluripotent stem cells can give rise to any fetal or adult cell type. However, alone they cannot develop into a fetal or adult organism because they lack the potential to contribute to extraembryonic tissue, such as the placenta.
Cell Biomarkers for pluripotency • Biomarker-a molecule that is present (or absent) from a particular cellular type • Cell sorting techniques are based on cellular biomarkers • A biomarker can be used to identify a cell population, make a diagnostic, measure the progress of disease or the effects of treatment • One example of cellular biomarker is the protein Oct-4 that is found in embryonic stem cells
IPS cells Induced pluripotent stem cells-type of pluripotent stem cell artificially derived from a non-pluripotent cell - typically an adult somatic cell - by inducing a "forced" expression of specific genes. Discovered by Shinya Yamanaka, John Gurdon, and team
Somatic cells • any biological cell forming the body of an organism; that is, in a multicellular organism, any cell other than a gamete, germ cell, gametocyte or undifferentiated stem cell
Cell induces teratoma in SCID mouse • Teratoma-A teratoma is an encapsulated tumor with tissue or organ components resembling normal derivatives of all three germ layers. The tissues of a teratoma, although normal in themselves, may be quite different from surrounding tissues and may be highly disparate; teratomas have been reported to contain hair, teeth, bone and, very rarely, more complex organs or processes such as eyes, torso, and hands, feet, or other limbs.
USED TODAY • SCID mouse-SCID mice were and still are used in disease, vaccine, and transplant research, especially as animal models for testing the safety of new vaccines or therapeutic agents in people with weakened immune systems.
WHAT IS SCID • SCID(Severe combined immunodeficiency)-is a genetic disorder in which both "arms" (B cells and T cells) of the adaptive immune system are impaired due to a defect in one of several possible genes. SCID is a severe form of heritable immunodeficiency. It is also known as the bubble boy disease because its victims are extremely vulnerable to infectious diseases
Cell with GFP followed in chimera embryos > egg and sperm • green fluorescent protein (GFP) is a protein composed of 238 amino acid residues (26.9kDa) that exhibits bright green fluorescence when exposed to light in the blue to ultraviolet range • [Insert chimera embryo picture cause I can’t get a picture]
Cells form an embryo in 'Tetraploid Complementation' Test • 'Tetraploid Complementation' Test -a technique in biology in which cells of two mammalian embryos are combined to form a new embryo. It is used to construct genetically modified organisms, to study the consequences of certain mutations on embryonic development, and in the study of pluripotent stem cells. • Normal mammalian somatic cells are diploid: each chromosome (and thus every gene) is present in duplicate. The assay starts with producing a tetrapod cell in which every chromosome exists fourfold. This is done by taking an embryo at the two-cell stage and fusing the two cells by applying an electrical current. The resulting tetraploid cell will continue to divide, and all daughter cells will also be tetraploid.
'Tetraploid Complementation' Test cont. • Such a tetraploid embryo can develop normally to the blastocyst stage and will implant in the wall of the uterus. The tetraploid cells can form the extra-embryonic tissue (placenta etc.), however a proper fetus will rarely develop. • The tetraploid complementation assay is also used to test whether induced pluripotent stem cells (stem cells artificially produced from differentiated cells, e.g. from skin cells) are as competent as normal embryonal stem cells. If a viable animal can be produced from an induced pluripotent stem cell using the tetraploid complementation assay, then the induced stem cells are deemed equivalent to embryonal stem cells
Shinya Yamanaka • Japanese physician that discovered that mature cells can be converted into stem cells. • Awarded the Nobel Prize for Physiology or Medicine • In 2006, he and his team generated induced pluripotent stem cells (iPS cells) from adult mouse fibroblasts
John Gurdon • A British developmental biologist that best known for his pioneering research in nuclear transplantation and cloning • Worked with Yamanaka and was awarded Nobel Prize for Physiology or Medicine
James Thomson • an American developmental biologist best known for deriving the first human embryonic stem (ES) cell line in 1998 and for deriving human induced pluripotent stem (iPS) cells in 2007. • Human embryonic stem cells can divide without limit, and yet maintain the potential to make all the cells of the body. This remarkable potential makes them useful for basic research on the function of the human body, for drug discovery and testing, and as a source of cells and tissues for transplantation medicine
Ian Wilmut • an English embryologist and Chair of the Scottish Centre for Regenerative Medicine at the University of Edinburgh.He is best known as the leader of the research group that in 1996 first cloned a mammal from an adult somatic cell, a Finnish Dorset lamb named Dolly. He was granted an OBE in 1999 for services to embryo development • Wilmut was the leader of the research group that in 1996 first cloned a mammal, a lamb named Dolly. Dolly died of a respiratory disease in 2003. However, in 2008 Wilmut announced that he is to abandon the technique of somatic cell nuclear transferby which Dolly was created in favour of an alternative technique developed by Shinya Yamanaka
New iPSFacilites at Harvard, Toronto, Kyoto • In 2008, Harvard University, along with universities in Toronto and Kyoto, established entire facilities devoted to iPS cell studies
Reference • William K. Purves, Gordon H. Orians, David Sadava, H. Craig Heller, Craig Heller (2003). Life: The Science of Biology(7th ed.), pp. 823–824 • http://www.thefreedictionary.com/dedifferentiation • http://en.wikipedia.org/wiki/Cell_potency • http://en.wikipedia.org/wiki/Biomarker_(cell) • http://en.wikipedia.org/wiki/Teratoma • http://en.wikipedia.org/wiki/Severe_combined_immunodeficiency
Reference • http://en.wikipedia.org/wiki/Chimera_(genetics) • The tetraploid complementation assay is also used to test whether induced pluripotent stem cells (stem cells artificially produced from differentiated cells, e.g. from skin cells) are as competent as normal embryonal stem cells. If a viable animal can be produced from an induced pluripotent stem cell using the tetraploid complementation assay, then the induced stem cells are deemed equivalent to embryonal stem cells
http://en.wikipedia.org/wiki/Ian_Wilmut • http://www.nature.com/news/2009/090422/full/458962a.html • ictsd.org/i/publications/11770/ • www.wipo.int/freepublications/en/intproperty/.../wipo_pub_941.pdf • www.telegraph.co.uk › Science › Science News • science.howstuffworks.com/life/genetic/cloning3.htm
www.ndsu.edu/pubweb/~mcclean/plsc431/mutation/mutation5.htm • www.nlm.nih.gov/medlineplus/ency/article/001316.htm • www.scid.net/ • www.conncoll.edu/ccacad/zimmer/GFP-ww/GFP-1.htm • ciceet.unh.edu/powerpoint/ringwood-methods.pdf • http://www.britannica.com/EBchecked/topic/644616/Sir-Ian-Wilmut/281350/Dolly-and-Polly
THANK YOU By: Bradley Varner & Chris Kohl