Cloning Extinct Animals
Perhaps one of the most controversial issues of the new century is that of cloning. While scientists have been able to successfully clone animals, it remains to be seen how the genetic lineage of the subjects will be altered. Already, we know that “Dolly”, a sheep that was the world's first ever cloned animal, was weaker than the original, and has suffered through a series of illnesses, including arthritis. She was susceptible to premature aging. Today many more animals have been cloned successfully, including endangered species. The issue of human cloning has also generated public outcry, with many agreeing on a ban. But how about cloning extinct animals?
The blockbuster hit Jurassic Park, based on the Michael Crichton novel of the same name, introduced the theory that scientists could bring dinosaurs back to life by using genetic material from dinosaurs combined with that of amphibians (the only vertebrates able to regenerate lost limbs). While dinosaur DNA could only have been extracted from blood inside mosquitoes that were preserved in amber to suit the story, it is in fact possible for us to get material from more recent extinct animals to try and bring a lost species back. That is where science fiction ends and science fact begins!
The magical thing about DNA is that it creates all the instructions to build an individual. Ultimately if we can get hold of that code, we can use it to create life. When the technology that created Dolly and other cloned animals proved itself, scientists began to wonder whether the DNA of extinct species could be used to bring them back to life.
It will be impossible to clone dinosaurs, because DNA only survives for about 10.000 years and the dinosaurs became extinct about 65 million years ago, so there is little hope of ever being able to clone a dinosaur from ancient DNA. There have been attempts to clone more recently extinct animals like the woolly mammoth, but finding suitable mammoth DNA has proved impossible. In February 2001, scientists working on the DNA of ancient birds at Oxford University reported that it would be highly unsuitable for cloning. The DNA of Moas from New Zealand, which became extinct about 500 years ago consisted of highly repetitive stretches of junk DNA, which would according the scientists be impossible to link together correctly.
More recently would seem easier to clone. However, there are some potential stumbling blocks. The scientists need near-perfect DNA to attempt cloning. If the scientists only clone from a very few animals or even only one, it would be difficult to establish a breeding population (especially if all the animals were the same sex!). This means also that there would be very little genetic diversity in any new group of animals. This has already led to (inbreeding) problems in more traditional conservation attempts based on just a few individuals. Many animals went extinct due to loss of their natural habitat, so if no suitable habitat will be available the resurrected species would be condemned to life in zoos. Another main concern about cloning extinct animals is that cloning might lead people to think of extinction as a temporary state. It might therefore detract from attempts to preserve rare species and habitats.
Current Cloning Projects
The most hopeful cloning project is that of the Pyrenean ibex (Capra pyrenaica pyrenaica). In the spring of 1999, Spanish biologists working for the Aragon regional government captured the last Pyrenean Ibex, named Celia. The biologists took blood, tissue (from her ear) and faeces samples. The samples were taken to preserve the Pyrenean Ibex's cell line for possible future cloning purposes. (Associated Press 2000; BBC News 2000; Perez et al. 2002) They were just on time, because the very last living Pyrenean Ibex was found dead on 6 January 2000 under a fallen tree in Ordesa National Park in Spain. Forest rangers in the Northeast of the country near the French border found the 13-year-old female with her skull crushed. (Associated Press 2000; BBC News 2000; McCarthy 2000)
Photo: fearing the worst, Spanish biologists including Alberto Fernandez and José Folch working for the Aragon regional government captured the last Pyrenean Ibex (Capra pyrenaica pyrenaica) in spring 1999 and took a tissue sample from her ear, to preserve the Pyrenean Ibex's cell line in case they needed to clone it. Then they attached an electronic tracer to the animal and released it. Courtesy Advanced Cell Technology, Inc.. All rights reserved.
In the spring of 1999, Spanish biologists working for the Aragon regional government captured the last Pyrenean Ibex, named Celia. The biologists took blood, tissue (from her ear) and faeces samples. The samples were taken to preserve the Pyrenean Ibex's cell line for possible future cloning purposes. (Associated Press 2000; BBC News 2000; Perez et al. 2002)
On 8 October 2000, Biotech company Advanced Cell Technology, Inc. announced that the Spanish government has agreed to Advanced Cell Technology (ACT)'s offer to use interspecies nuclear transfer cloning technology in collaboration with other scientific partners to clone the extinct Pyrenean Ibex from the tissue that has been taken in 1999. Celia was able to provide perfect tissue samples for cloning. ACT has agreed with the government of Aragón, that the future cloned Pyrenean Ibexes will be returned to their original habitat. (ACT 2000)
In July 2003, scientists announced that the first intent to clone the Pyrenean Ibex has failed. Three teams of scientists, two Spanish and one French, are involved in the cloning project. The project is coordinated by the Service of food and agriculture Investigation of the Government of Aragon (Servicio de Investigación Agroalimentaria del Gobierno de Aragón) and by the National Institute of Investigation and Food and Agrarian Technology (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria INIA), and also the National Institute of the Agrarian Investigation of France will take part in the project. The director of the project and leader of the Unit of Technology in Animal Production of the Service of food and agriculture Investigation (SIA) of Aragon is José Folch, one of the scientists that captured the last female Celia to take tissue samples. A total of 285 cloned embryos were created en 54 of of them were transferred into twelve Spanish Ibexes of the so-called subspecies Capra pyrenaica hispanica from the Tortosa y Beceite National Game Reserve (Catalonia and Aragón, Spain) and ibex-domestic goat hybrids. However, only two embryos maintained the gestation during near two months. The gestation was interrupted spontaneously in January 2003. (Barameda.com.ar 2003; El Mundo 2003)
In January 2009, the Pyrenean Ibex became the first extinct animal to be resurrected by cloning. DNA from the tissue taken from the last Pyrenean Ibex named Celia had been transplanted into eggs from domestic goats. From the 439 embryos that had been created 57 were implanted into surrogate female domestic goats. Only seven of the embryos resulted in pregnancies, but only one of the goats gave birth to a female Pyrenean Ibex. This newborn ibex died after seven minutes due to breathing difficulties. Flaws in the DNA may have resulted into physical defects in its lungs. (Gray and Dobson 2009) However, this latest cloning attempt proved that Celia's cells are viable and that domestic goats cab be used as surrogates (Brahic 2009). The project will continue.
Attempts to clone Celia have highlighted a major problem: even if it is possible to produce another healthy Pyrenean ibex, there wouldn’t be a male of the female clone to breed with. One solution could be to cross Celia’s clones with males of another subspecies, although the offspring would be less “Pyrenean ibex” than Celia. A more ambitious plan would be to remove one X chromosome and add a Y chromosome from another still existing subspecies, creating a male Pyrenean ibex. (Zitner 2000)
The project to bring the Tasmanian Tiger or Thylacine (Thylacinus cynocephalus) back from extinction began in 1999 when Australian Museum scientists extracted DNA from an ethanol-preserved female pup in its collection.
In 2001, further DNA was extracted from two other preserved pups; the tissue source for the DNA was bone, tooth, bone marrow, and dried muscle. Dr. Mike Archer, director of the Australian Museum, said the alcohol-preserved female pup's DNA had given the scientists the Tasmanian tiger's X chromosome and the other samples the male Y chromosome. However, even with such well-preserved samples, the DNA is very fragmented and it might turn out to be impossible to string it all together correctly.
On 28 May 2002, the scientists from the Australian Museum in Sydney announced a breakthrough in efforts to clone the extinct Tasmanian wolf, saying they had replicated some of the animal's genes using a process called PCR (Polymerase Chain Reaction). These PCR's show that short fragments of the DNA are undamaged and undoubtedly Tasmanian Tiger DNA, and that there is no reason why these should not work in a living cell.
The next stage is to make large quantity copies of all the genes of the Tasmanian tiger so these can be used to construct synthetic chromosomes. The scientists said they hoped to clone a Tasmanian tiger in 10 years if they were successful in constructing large quantities of all the genes of the Tasmanian tiger and sequencing sections of the genome to create a genetic library of Tasmanian tiger DNA.
But Dr. Mike Archer said the technology for the final stage of cloning, putting the Tasmanian tiger's genetic material into a Tasmanian devil host cell which has been stripped of the devil's genetic material was still to be developed. "We don't know the length of this journey. It's up to the speed with which technology keeps pace with the vision. But I am optimistic," he said. The ultimate aim of this project was to clone a viable reproducing population of Tasmanian tigers in the wild.
On 15th February 2005 sad news appeared. The resurrection of the Tasmanian tiger will have to wait. After five years trying to extract DNA from preserved Tasmanian tigers in an effort to bring the lost marsupial back to life, the Australian Museum has abandoned the ambitious project, after finding its supply of Tasmanian tiger DNA too degraded. The museum said it lacked the skills and facilities to continue the project. Professor Archer, now the dean of science at the University of New South Wales, says the cloning project has lost steam since he left the museum in 2003. In a statement to ABC Science Online, Professor Archer says he is disappointed by the museum's decision but he says he still hopes it might be possible to bring the Tasmanian tiger back to life. "I and other colleagues remain interested in the project and I don't think that it will simply die because the museum can't proceed," he says. "The technology to make it happen is improving all the time. And I believe science has a duty to continue to assemble the building blocks that will be needed to do it."
On 15th May 2005, three months after the Australian museum shelved plans to clone the tiger, the announcement came that a group of universities and a research institute are planning to revive the project. Mike archer, Dean of Science at the University of New South Wales, was quoted as saying that researchers from NSW and Victoria states were likely to join the programme, which involves recovering DNA from a pup preserved in 1866 to breed a living specimen. Hopefully this time they will succeed!
More information about this cloning project can be found on the Australian Museum’s website: http://www.austmus.gov.au/thylacine/.
Scientists, ethicists, representatives from the Maori, and students from the Hastings Boys High School did meet in Hastings, New Zealand on 9 and 10 July 1999, to discuss the technical feasibility and moral permissibility of reviving the Huia (Heteralocha acutirostris). After that meeting they have determined that efforts to revive the extinct Huia bird through cloning should begin immediately. On 20 July 1999 New Zealand approved cloning the extinct Huia.
The project began when students at the Hastings Boys High School in New Zealand wondered if their school emblem, the extinct Huia, could be revived. The students researched the idea, invited speakers and organised the conference in July 1999. Now the schoolboy fantasy, inspired by Dr. Michael Crichton's best-selling novel, Jurassic Park, is leading to cutting edge scientific research.
The next step in the cloning progress involves searching for whole cells or an intact nucleus in the bones and tendons of preserved specimens. If none are found, the scientists will try to extract DNA from those specimens and use 'Jurassic Park technology', called template cloning. This is possible in principles although it has not been successfully used in practice.
The difference between Jurassic Park and cloning the Huia is that the Huia has only be extinct since the beginning of the 20th century. We can be confident of having multiple copies of its DNA. If a whole cell is not found, scientists may be able to perform a miracle. If a whole cell is available, then the procedure is merely magic. In either case, man has the opportunity to right one of his crimes against nature. The Huia was one of 3 species of wattle birds (not related to Australian 'wattlebirds') in New Zealand and it is thought one of the other species could be used as the oocyte provider and surrogate parent.
The project, announced in 1999 was backed by an Internet start-up company which no longer exists, and I was unable to determine whether it is still proceeding. Do you have additional information, please send us an e-mail!
ACT (2000). Advanced Cell Technology Reaches Agreement with Spanish Government to Clone First Extinct Animals - ACT to clone recently extinct bucardo mountain goat from Spain. Advanced Cell Technology, Inc. (October 8, 2000). Downloaded from http://advancecell.com/pr_10-18-2000-bucardo.html.
Associated Press. (2000). Cloning may work for extinct goat. Environmental News Network (ENN), tuesday, january 11, 2000. Downloaded on 25 August 2001 from http://www.enn.com/news/wire-stories/2000/01/01112000/goatextinct_8961.asp.
Barameda.com.ar (2003). Fracasa la clonación de una cabra extinguida. 7 de julio de 2003. Downloaded from http://www.barrameda.com.ar/noticias/jul03/bucardo1.htm.
BBC News. (2000). Clone plan for extinct goat. BBC News Online, tuesday, 11 january 2000, 15:08 GMT. Downloaded on 25 August 2001 from http://news.bbc.co.uk/1/hi/sci/tech/598799.stm.
Brahic, C. (2009). Extinct animal cloned for the first time. Short Sharp Science - NewScientist (February 2, 2009). Downloaded from http://www.newscientist.com/blogs/shortsharpscience/2009/02/first.
El Mundo (2003). Fracasa la primera clonación de un animal extinto en España. Elmundo.es (Lunes, 07 de Julio de 2003). Downloaded from http://www.elmundo.es/elmundo/2003/07/06/ciencia/1057487983.html.
Gray, R. and Dobson, R. (2009). Extinct ibex is resurrected by cloning. Telegraph.co.uk (31 January 2009). Downloaded on 1 February 2009.
McCarthy, M. (2000). Last Pyrenean ibex killed by tree. The Independent (28 January 2000). Online article.
Perez, J.M., Granados, J.E., Soriguer, R.C., Fandos, P., Marquez, F.J., and Crampe, J.P. (2002). Distribution, status and conservation problems of the Spanish ibex, Capra pyrenaica (Mammalia: Artiodactyla). Mammal Rev. 32(1):26-39. Online full-text pdf.
|Citation:||Maas, P.H.J. (2010). Cloning Extinct Animals. In: TSEW (). The Sixth Extinction Website. <http://www.petermaas.nl/extinct>. Downloaded on .|
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|Updated:||24 July 2010|