Editing Embryonic stem cell (section)

==History==
* 1964: Lewis Kleinsmith and G. Barry Pierce Jr. isolated a single type of cell from a [[teratocarcinoma]], a tumor now known from a [[germ cell]].<ref>{{cite journal | vauthors = Kleinsmith LJ, ((Pierce GB Jr)) | title = Multipotentiality of Single Embryoncal Carcinoma Cells | journal = Cancer Res | volume = 24 | pages = 1544–1551 | year = 1964 | pmid = 14234000 | url = http://cancerres.aacrjournals.org/content/24/9/1544.short | access-date = 2016-04-05 | archive-date = 2016-10-06 | archive-url = https://web.archive.org/web/20161006125242/http://cancerres.aacrjournals.org/content/24/9/1544.short | url-status = live }}</ref> These cells were isolated from the teratocarcinoma replicated and grew in cell culture as a stem cell and are now known as embryonal carcinoma (EC) cells.{{Citation needed|date=December 2019|reason=removed citation to predatory publisher content}}  Although similarities in morphology and differentiating potential ([[pluripotency]]) led to the use of EC cells as the ''in vitro'' model for early mouse development,<ref>{{cite journal | author = Martin GR | title = Teratocarcinomas and mammalian embryogenesis | journal = Science | volume = 209 | issue = 4458 | pages = 768–776 | year = 1980 | pmid = 6250214 | doi = 10.1126/science.6250214| bibcode = 1980Sci...209..768M }}</ref> EC cells harbor genetic mutations and often abnormal [[karyotypes]] that accumulated during the development of the teratocarcinoma.  These genetic aberrations further emphasized the need to be able to culture [[pluripotent]] cells directly from the [[inner cell mass]].
[[File:Martin Evans Nobel Prize.jpg|thumb|140px|Martin Evans revealed a new technique for culturing the mouse embryos in the uterus to allow for the derivation of ES cells from these embryos.]]
* 1981: Embryonic stem cells (ES cells) were independently first derived from a mouse embryos by two groups.  [[Martin Evans]] and [[Matthew Kaufman]] from the Department of Genetics, [[University of Cambridge]] published first in July, revealing a new technique for culturing the mouse embryos in the uterus to allow for an increase in cell number, allowing for the derivation of ES cell from these embryos.<ref name="Evans M, Kaufman M 1981 154–6">{{cite journal | vauthors = Evans M, Kaufman M | title = Establishment in culture of pluripotent cells from mouse embryos | journal = Nature | volume = 292 | issue = 5819 | pages = 154–156 | year = 1981 | pmid = 7242681 | doi = 10.1038/292154a0| bibcode = 1981Natur.292..154E | s2cid = 4256553 }}</ref> [[Gail R. Martin]], from the Department of Anatomy, [[University of California, San Francisco]], published her paper in December and coined the term "Embryonic Stem Cell".<ref name="Martin G 1981 7634–8">{{cite journal | author = Martin G | title = Isolation of a pluripotent cell line from early mouse embryos cultured in medium conditioned by teratocarcinoma stem cells | journal = Proc Natl Acad Sci USA | volume = 78 | issue = 12 | pages = 7634–7638 | year = 1981 | pmid = 6950406 | doi = 10.1073/pnas.78.12.7634 | pmc = 349323| bibcode = 1981PNAS...78.7634M | doi-access = free }}</ref> She showed that embryos could be cultured ''in vitro'' and that ES cells could be derived from these embryos.
* 1989: Mario R. Cappechi, [[Martin J. Evans]], and [[Oliver Smithies]] publish their research that details their isolation and genetic modifications of embryonic stem cells, creating the first "[[knockout mice]]".<ref>{{cite web |title=The 2007 Nobel Prize in Physiology or Medicine – Advanced Information |url=https://www.nobelprize.org/nobel_prizes/medicine/laureates/2007/advanced.html |website=Nobel Prize |publisher=Nobel Media |access-date=2018-06-25 |archive-date=2018-06-25 |archive-url=https://web.archive.org/web/20180625075849/https://www.nobelprize.org/nobel_prizes/medicine/laureates/2007/advanced.html |url-status=live }}</ref> In creating knockout mice, this publication provided scientists with an entirely new way to study disease.
* [[File:Dolly clone.svg|thumb|Dolly the sheep cell differentiation]]1996: [[Dolly (sheep)|Dolly]], was the first mammal cloned from an adult cell by the [[Roslin Institute|Roslin Institute of the University of Edinburgh]].<ref>{{Cite web|title=The Life of Dolly {{!}} Dolly the Sheep|url=https://dolly.roslin.ed.ac.uk/facts/the-life-of-dolly/index.html|access-date=2022-02-21|language=en-US|archive-date=2021-11-11|archive-url=https://web.archive.org/web/20211111151011/http://dolly.roslin.ed.ac.uk/facts/the-life-of-dolly/index.html|url-status=dead}}</ref> This experiment instituted the proposition that specialized adult cells obtain the genetic makeup to perform a specific task; which established a basis for further research within a variety of cloning techniques. The Dolly experiment was performed by obtaining the mammalian udder cells from a sheep (Dolly) and differentiating these cells until division was concluded. An egg cell was then procured from a different sheep host and the nucleus was removed. An udder cell was placed next to the egg cell and connected by electricity causing this cell to share DNA. This egg cell differentiated into an [[embryo]] and the embryo was inserted into a third sheep which gave birth to the clone version of Dolly.<ref>{{Cite book|last1=Klotzko|first1=Arlene Judith|url=https://books.google.com/books?id=JVagpD0snTsC&dq=dolly+the+sheep+first+cloned+mammal&pg=PR14|title=A Clone of Your Own?|last2=Klotzko|first2=Visiting Scholar Royal Free and University College Medical School Arlene Judith|year=2006|publisher=Cambridge University Press|isbn=978-0-521-85294-4|language=en|access-date=2022-02-21|archive-date=2022-12-22|archive-url=https://web.archive.org/web/20221222121202/https://books.google.com/books?id=JVagpD0snTsC&dq=dolly+the+sheep+first+cloned+mammal&pg=PR14|url-status=live}}</ref>
* 1998: A team from the [[University of Wisconsin, Madison]] (James A. Thomson, Joseph Itskovitz-Eldor, Sander S. Shapiro, Michelle A. Waknitz, Jennifer J. Swiergiel, Vivienne S. Marshall, and Jeffrey M. Jones) publish a paper titled "Embryonic Stem Cell Lines Derived From Human Blastocysts". The researchers behind this study not only created the first embryonic stem cells, but recognized their pluripotency, as well as their capacity for self-renewal. The abstract of the paper notes the significance of the discovery with regards to the fields of developmental biology and drug discovery.<ref>{{cite journal |last1=Thompson |first1=James A. |last2=Itskovitz-Eldor |first2=Joseph |last3=Shapiro |first3=Sander S. |last4=Waknitz |first4=Michelle A. |last5=Swiergiel |first5=Jennifer J. |last6=Marshall |first6=Vivienne S. |last7=Jones |first7=Jeffrey M. |title=Embryonic Stem Cell Lines Derived From Human Blastocyst |journal=Science |date=6 November 1998 |volume=282 |issue=5391 |pages=1145–1147 |doi=10.1126/science.282.5391.1145 |pmid=9804556 |bibcode=1998Sci...282.1145T |doi-access=free }}</ref>
* 2001: [[President George W. Bush]] allows federal funding to support research on roughly 60—at this time, already existing—lines of embryonic stem cells. Seeing as the limited lines that Bush allowed research on had already been established, this law supported embryonic stem cell research without raising any [[Stem cell controversy|ethical questions]] that could arise with the creation of new lines under federal budget.<ref>{{cite news |title=President George W. Bush's address on stem cell research |url=http://edition.cnn.com/2001/ALLPOLITICS/08/09/bush.transcript/ |publisher=CNN Inside Politics |date=Aug 9, 2001 |access-date=June 25, 2018 |archive-date=June 13, 2018 |archive-url=https://web.archive.org/web/20180613180507/http://edition.cnn.com/2001/ALLPOLITICS/08/09/bush.transcript/ |url-status=dead }}</ref>
* 2006: Japanese scientists [[Shinya Yamanaka]] and Kazutoshi Takashi publish a paper describing the induction of pluripotent stem cells from cultures of adult mouse [[fibroblasts]]. [[Induced pluripotent stem cell|Induced pluripotent stem cells (iPSCs)]] are a huge discovery, as they are seemingly identical to embryonic stem cells and could be used without sparking the same moral controversy.<ref>{{cite journal |last1=Yamanaka |first1=Shinya |last2=Takahashi |first2=Kazutoshi |title=Induction of Pluripotent Stem Cells From Mouse Embryonic and Adult Fibroblast Cultures by Defined Factors |journal=Cell |date=25 Aug 2006 |volume=126 |issue=4 |pages=663–676 |doi=10.1016/j.cell.2006.07.024|pmid=16904174 |hdl=2433/159777 |s2cid=1565219 |hdl-access=free }}</ref>
* January, 2009: The [[US Food and Drug Administration]] (FDA) provides approval for [[Geron Corporation]]'s phase I trial of their human embryonic stem cell-derived treatment for [[spinal cord injuries]]. The announcement was met with excitement from the scientific community, but also with wariness from stem cell opposers. The treatment cells were, however, derived from the cell lines approved under George W. Bush's [[Stem-cell policy|ESC policy]].<ref>{{cite journal |last1=Wadman |first1=Meredith |title=Stem cells ready for primetime |journal=Nature |volume=457 |issue=7229 |pages=516 |doi=10.1038/457516a |pmid=19177087 |date=27 January 2009|doi-access=free }}</ref>
* March, 2009: Executive Order 13505 is signed by [[President Barack Obama]], removing the restrictions put in place on federal funding for human stem cells by the previous presidential administration. This would allow the [[National Institutes of Health]] (NIH) to provide funding for hESC research. The document also states that the NIH must provide revised federal funding guidelines within 120 days of the order's signing.<ref>{{cite journal |title=Executive Order 13505—Removing Barriers To Responsible Scientific Research Involving Human Stem Cells |journal=Federal Register: Presidential Documents |date=11 March 2009 |volume=74 |issue=46 |url=https://www.gpo.gov/fdsys/pkg/FR-2009-03-11/pdf/E9-5441.pdf |access-date=2018-06-25 |archive-date=2018-11-01 |archive-url=https://web.archive.org/web/20181101193558/https://www.gpo.gov/fdsys/pkg/FR-2009-03-11/pdf/E9-5441.pdf |url-status=live }}</ref>