Klonierung von Säugetieren und Gentechnologie
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Klonierung von Säugetieren und Gentechnologie Dolly Dolly with her first newborn, Bonnie • Born in July 1996 at the Roslin Institute in Scotland • First mammal to be cloned from an adult mammal using the nuclear transfer technique • 277 attempts were made before the experiment was successful •Dolly died in February 14, 2003 of progressive lung disease at the age of 6; whereas normal sheep can live up to 12 years of age. Mammal Cloning http://www.howst uffworks.com/cloni ng.htm/printable January 8, 2001 Noah, a baby bull gaur, became the first clone of an endangered animal. Tetra 1998 – 50 mice were cloned in three generations from a single mouse 1998 – 8 calves were cloned from a single adult cow, but only 4 survived to their first birthday 1999 – A female rhesus monkey named Tetra was cloned by splitting early embryo cells. 2000 – Pigs and goats reported cloned from adult cells 2002 – Rabbits and a kitten reported cloned from adult cells http://hs.houstonisd.org/ hspva/academic/Science/ Thinkquest/gail/text/bene fits.html • Genetic Savings and Clone has successfully cloned cats, including CC (above), the first cloned cat. The • company had four clients sign up to • have their domestic cats cloned for U.S. $50,000 each. Klonierung von Haustieren Genetic Savings & Clone promises to clone anyone’s pet — for $50,000 First pet clone is a cat Vergleich der Erfolgsrate bei verschiedenen Tieren Species Number of oocytes used Number of live offspring Notes Mouse 2468 31 (1.3%) - Bovine 440 6 (1.4%) 2 died Sheep 417 14 (3.4%) 11 died within 6 months Pig 977 5 (0.5%) - Goat 285 3 (1.1%) - The table shows success rates of cloning when mature mammal cells were used. Yanagimachi, R. 2002. "Cloning: experience from the mouse and other animals." Molecular and Cellular Endocrinology. 21 March, 187. Kern - Transplantation Enucleation of donor cell Nuclear Transfer • the nucleus of the individual to be cloned is transferred to the cytoplast in one of the 2 ways: 1) electrofusion – whole nucleus donor cell injected beneath the zona pellucida (the outer membrane of the oocyte) and fusion of cells induced by electrical impulses 2) nuclear injection – naked nucleus microinjected into cytoplast Zusammenfassung oocyte cytoplast ENUCLEATION NUCLEAR TRANSFER cytoplast clone cell genetic reprogramming Induktion der EmbryoEntwicklung developing embryo in culture Implantation embryo uterus of surrogate mother Genetische Reprogrammierung Fig. 5 from Nature Reviews Genetics 3: 671 Cloning Humans http://www.cnn.com/2001/WORLD/europe/08/06/clone.doctor/index.html Klonierung von Menschen? therapeutisch oder reproduktiv? http://www.humancloning.org/ Human Cell Embryos Clonaid http://www.clonaid.com/ “The main goal of CLONAID™ is to offer reproductive human cloning on a worldwide basis to infertile couples, homosexual couples, people infected with the HIV virus as well as to families who lost a beloved family member.” http://www.clonaid.com/ • Clonaid was founded by members of a religious sect called the Raelians • On Thursday, December 26, 2002, Clonaid claimed to have successfully created the first human clone, a 7 pound baby girl named Eve • Eve was created using DNA from her mother’s skin cells and is a genetic twin of her mother, a 31-year-old American citizen • After originally stating that a panel of independent scientists would be allowed to verify that Eve was a clone of her mother, on January 3, 2003 it was announced that no tests would be performed to prove Eve’s existence or that she was a clone • Clonaid now claims that 5 cloned humans have been born, the most recent being born February 4, 2003 • There is still no proof that a human clone has ever been born • Many scientists believe that the Clonaid claim is a hoax Klonierung beim Menschen: Sixth Cloned Baby Born DownUnder ! The 6th cloned baby was born on Thursday the 5th of February in Australia.The Clonaid team, after 20 more implantations, had 8 successful pregnancies. Probleme mit Klonierung • Klonieren ist nicht sicher • beim Klonieren entstehen Entwicklungsdefekte •Klone scheinen vorzeitig zu altern Clones are Not Exact Copies • A clone’s mitochondrial DNA comes from the donor egg cell. Unless the donor egg comes from the person being cloned their mitochondrial DNA will be different. • Random developmental events, such as X-chromosome inactivation, can cause clones to differ greatly in appearance. • Different environmental and social factors can cause clones to vary greatly in both appearance and personality. • No clone will ever be exactly the same as the original. • Rainbow and Cc (cloned cat) • Cloned cat hardly resembles her original http://www.crystalinks.com/cloningcats.html Geburtsdefekte bei Klonen • Klone leiden unter dem “large offspring syndrome”, beim dem sowohl das Neugeborene als auch die dazu gehörige Plazenta ungewöhnlich groß sind • Klone haben oft unerklärliche Atmungs- oder Kreislauferkrankungen • Das Immunsystem ist häufig geschwächt oder funktionsunfähig • Sehr wenige Klone erreichen das adulte Alter Sicherheit bei der Klonierung •Die Erfolgsrate bei der Klonierung ist teilweise extrem niedrig •Beim Klonieren entstehen häufig Entwicklungsdefekte •Dadurch haben Klone oft Geburtsfehler • Dolly (left) and her surrogate mother • It took 277 attempts before Dolly became the first cloned sheep Vorzeitige Alterung bei Klonen • Klone scheinen schneller zu alter als normale Individuen • Dolly zeigte in relativ jungen Jahren heftige Arthritis • Bei Dolly hatten die Telomere (spezielle Strukturen an den Chromosomenenden) eine zu geringe Größe •Neuere Untersuchungen zeigen aber, dass die Telomerase in Embryonalstadium aktiv wird und die Telomerlängen größer werden http://users.rcn.com/jkimball.ma.ultranet/BiologyPag es/T/Telomeres.html http://www.zks.uni-freiburg.de/dereg_new/diagramme.html http://www.zks.uni-freiburg.de/dereg_new/diagramme.html http://www.zks.uni-freiburg.de/dereg_new/diagramme.html Erfolgreiche Gentherapie mit tödlichen Nebenwirkungen • X-linked severe combined immunodeficiency disease (X-SCID), bekannt als "bubble baby syndrome.„ • 11 Patienten fehlte das Gen IL2RG • Das Gen wurde in Stammzellen der Kinder überführt • Zwei (inzwischen 3) Kinder entwickelten Leukämie, bzw eine lymphatischen Tumor • Das Transgen war bei beiden Kindern in das Tumorgen LMO2 hinein gesprungen Pflanzengentechnologie Ein natürlicher Helfer für die Pflanzengentechnologie ist das Bakterium Agrobakterium tumefaciens Tumorgallen durch A. tumefaciens Pflanzengentechnologie A. tumefaciens injiziert die T-DNA in die Pflanzenzelle, um sie zu mehr Wachstum anzuregen Pflanzengentechnologie DNA-Transfer mit Hilfe von Agrobakterium tumefaciens http://www.sciencemag.org/cgi/reprint/294/5550/2317.pdf Typischer Pflanzenvektor auf der Basis des Agrobakterium tumefaciens Ti-Plasmids Veränderte Blütenfarben: die blaue Nelke „moon dust“ No.9013 2005. 1. 21 Blue Carnation “Moon dust” released in Japan nationwide - The one and only Blue Carnation in the world - Die erste „blaue“ Rose durch siRNA DFR-Gen: Dihydroflavonolreductase
