The Technograph

The modern concept of cloning has been dreamt about for decades. The idea of creating an identical copy of an organism was often thought of as purely science fiction. Today, however, cloning is a very real biological practice.

The first animals to be cloned were frogs, in 1952, using embryonic cells. This technique opened the door to new experiments and successfully cloned carp, in 1963, and mice, in 1986. In the late 1990’s a new process was developed by using adult body cells, and the world famous “Dolly” the sheep was successfully cloned in 1996. Since then, many more animals have been reproduced including a monkey, a gaur, cattle, a cat, a mule, a horse, a water buffalo, and a camel. A pig was cloned in 2000 using adult body cells, which created a litter of five more clones; this particular process was used in experiments to genetically engineer pig organs for human transplants.

In recent history, human cloning has been under experimentation, but not without controversy. In 1998, the first hybrid human clone was created from a man’s leg cell and a cow’s egg who’s DNA was removed. The clone was destroyed after 12 days to respect the idea that an embryo is not considered a person before 14 days. In 2008, it was announced that five mature human embryos were created using adult skin cells. The embryos were destroyed by the scientists stating that “using the technology for reproductive cloning would be both unethical and illegal.”

One of the biggest questions about cloning today is the idea of reproducing something that has died, by replicating its DNA. Extinct species, for example, could potentially be brought back to life by cloning. This idea and some of its more negative implications were displayed in the classic film series Jurassic Park.

The process of cloning extinct animals hinders on one important piece of the puzzle: DNA. Not just a portion of the DNA, but a full DNA sequence; which is harder to come by than you think. For ancient species, it is impossible, without a time machine, to get DNA. Some animals, however, have been preserved in a natural ice bath for years, and may contain good-quality DNA. According to scientists, genetic information, even frozen, could likely only survive 100,000 years; which brings many to conclude that dinosaur repopulation is out of the question. The best current candidate for cloning is the woolly mammoth. Today’s researchers are working hard to fully sequence the mammoth DNA, but they’ve been slowed by DNA degradation. Another difficulty with breeding these animals is that DNA from a single specimen could not be used to sexually reproduce. Using both a male and female specimen would increase the likelihood of a successful reproduction. This possibility brings more questions, however, including whether or not the animal could survive without parents to teach them natural behavior. While the technology for DNA cloning isn’t quite there, researchers are storing up DNA samples to use in the future. The San Diego Zoo and the Audubon Center for Research of Endangered Species in New Orleans are home to cryonic facilities known as a “Frozen Zoo” that contains DNA, sperm, eggs, and embryos from animals and plants. The samples have been collected to “protect the diversity of the gene pool for critically endangered species.”

In 2006, researcher David Ehrenfeld conducted a review on the cloning of extinct species, and his conclusion is as follows:

“Vertebrate cloning poses little risk to the environment, but it can consume scarce conservation resources, and its chances of success in preserving species seem poor. To date, the conservation benefits of transgenics and vertebrate cloning remain entirely theoretical, but many of the risks are known and documented. Conservation biologists should devote their research and energies to the established methods of conservation, none of which require transgenics or vertebrate cloning.”

In other words, Ehrenfeld believes that chances of successful cloning are slim, and the negative implications of such operations are too important to overlook. He recommends the time and money that he believes would be wasted on these projects be used on methods of conservation of current species.

As for now, questions still remain and research continues; only time will tell where technology will take us. Can you imagine visiting a wholly mammoth in a zoo? Or having a dinosaur as a pet? Sounds like science fiction, right? Or is this our future?

Let me know what you think about cloning extinct species. Leave your comments on readtechnograph.com and learn more about what UIUC is doing for cloning at the Institute for Genomic Biology (http://www.igb.illinois.edu/).

Tagged with: mammoth, genetics, elephants, ehrenfeld, embryonic