Thursday, June 30, 2011

Which one is my clone?

Imagine you love you pet cat. You love Fluffy so much that you want to get a clone made of it because it means that much to you. Well there's a little bit of a problem: the clone won't look or act anything like Fluffy. Weird, I know but this is because there are two major factors that make something look and act the way it is. One is genetics, which the clone will be exactly like Fluffy down to just about every nucleotide. The other factor, that really makes Fluffy who he is, is the environment. One that has a large key of making something look a certain way is the maternal effect. Depending on where the egg settles down in a uterus, what the mother eats (drinks, is exposed to), etc, etc, this will ultimately make or break this organisms development. Even after birth, the environment the organism is brought up in has a great impact on how it looks and acts.

If I was born under healthy conditions and my mother ate properly while pregnant, was healthy and I was brought up during the 90's in a middle class family I would become the person I am today. However if I clone myself in the year 2020 my clone will not be anything like me. Imagine if the carrier smokes daily, has a disease, and eats only hot dogs during pregnancy this child may have serious complications coming into the world. Now also imagine the child is raised and taught in front of a computer and is raised by a upper class family in Europe. Because off all the difference I may hate my clone, we may never get along, and due to his carrier's behavior chances are I wouldn't recognize it as my clone.

When they first cloned Dolly the sheep people had an idea that it would age extremely quickly (for whatever reason). Now Dolly died of a rare form of lung cancer which many thought was a clear sign of being cloned. This is not true though, she was actually one a several in her barn to contract this disease. The disease is actually transferred when an animal comes into close contact with a carrier (the disease has a 3 month latent period so once one sheep had it the scientists were sure most of the one's in the barn had it). Another health issue Dolly seemed to have was arthritis, and though it is seen in older sheep it is rarely seen in sheep as young as Dolly was when she first developed it. Some speculated that this too must be a sign of early aging due to cloning. However this can also be explained, Dolly was a very unusual sheep who enjoyed rearing up on its back 2 legs in order to be fed and posed for many pictures. Doctors that examined Dolly did agree that this could easily have caused the arthritis and it was nothing out of the ordinary. Once Dolly passed away scientists allowed tissue samples to be thoroughly examined. This is what is really interesting: they found that Dolly's telomeres were shorter than they should be. Telomeres are essentially the glue holding your DNA together at the ends, over time these telomeres shorten which puts a cap on how many times each cell can divide. Although this did not kill Dolly is kind of meant she wasn't as older as she really was. Although I can't explain why or how this happened I do have an idea. It is possible that the DNA taken from the host sheep had shortened telomeres that what is seen in a new born sheep (because the host DNA has shorter telomeres than a newborn). Over Dolly's life the telomeres could have shortened to the point they were seen at after she died. There are many other theories about why Dolly's telomeres were shortened and even though they were shorter that doesn't actually mean anything. Telomeres are torn very slightly during each cell replication cycle, but they are also repaired. The shortening of telomeres is such a slow process that it is actually possible that Dolly just got really unlucky with telomere shortening. However this could also be seen that a clone may have a flaw in repairing broken telomeres.

There are many flaws in cloning and even if you want a clone of you right this second you cannot get that. The best chance you have of getting a clone of something that is the same age of the host is starting the cloning process the day the animal is conceived. Good luck. Also you have to make sure it develops under the exact same conditions, is brought up in the exact environment, and every single genetic mistake is done at the same time (random chance). In short, it's not going to happen.

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