What went wrong with Dolly?

F

firefighter

Registered Senior Member
What went wrong with Dolly?

Why are the personality traits and physical markings (coats) of cloned cats so markedly different from that of their respective DNA donor cats?
 
This is a really simplified explanation. I'm going to assume that people are familiar with the telomere theory of aging.

The theory on why Dolly had problems has to do with one of the current theories on aging. Since they took the nucleus out of a middle-aged sheep (the donor was 6 years old), the telomeres at the end of her DNA strands were already partly worn. So, she was essentially born middle-aged.

They're not entirely sure why CC doesn't look or act like her 'mother'.
 
didn't

didn't the nucleus of dolly come from a cell from the dermal layer? There was probably some mutations already existant in the donar cell when they performed the cloning.
 
from Latimes:

"She got incredible attention," Schatten said. "And as a result of that incredible attention, she got a little weird."


so dolly might be suffering from symptoms normally associated with stardom...elvis anyone
 
Interesting, Idle Mind. Thanks.

Now, it looks like cancer cells might hold the key to eternal youth with their ability to synthesize telomerase and replicate indefinitely without shortening of the telomeres.

There's a silver lining in every cloud.
 
Funny thing is that Charlie Chaplin at age 81 fertilised a female and the offspring was not born "middle-aged" at all. Apperantly normal human reproduction somehow resets the telemores?? or maybe it has something to do with stemcells.

Anyway I trust the biogeeks will find out soon and perfect the cloning process....
 
Yes, normal reproduciton does reset the telomeres.

However, when some animals are cloned (cows and mice I think), the telomeres actually are longer in the clone than they are in the donor. We don't really understand why yet.
 
Regarding cc the cat, no one says a cloned human would have the same personality as the original, and I don't know how you measure the "personality" of a cat. As for the spots, I think I read that they are determined by conditions in the womb as much as by genetics. It was not a surprise that the cat didn't have the same spots (it might surprise some idiot pet owner trying to clone her cat, though).

I haven't seen anyone report on the typical lifespan of a sheep. I'm guessing it's something like a dog-- maybe 12-15 yrs? But that's a complete guess.

Anyway, we've got quite a few cloned animals out there and will be able to make some statistical statements about lifespan for cloned animals at some point.
 
Cat color is control by random variation and activation of several genes; it’s like asking why all the hair follicles on dolly are not in the exact same spots as her original. As for telomeres: this problem is being dealt with in that a clone can be induced to restore its telomere lengths by using telomerase inducing drugs or injecting pure telomerase into a single celled clone embryo.

Telomerase is a nature protein the body uses to reset telomere lengh in many body cell: most commonly testis and ovaries in meiosis.
 
what went wrong?

We created her. We observed her genome. We killed her.
It was a successful experiment. I don't think anything went wrong, because there wasn't a hypothesis that she would be fine or not fine. I think we just wanted to apply the theory of mammalian synthesis of telomerase and the behavior of telomeres to experiment. For me there was more to the experiment. I wanted to give my pro cloning agenda a test drive. I'm glad that we did it. I think much was learned. I'm sad for Dolly.
:(
 
proteome

proteome didn't necessarily say something incorrect, the experiment overall was wildly succesful. Nothing really DID go wrong, but the early death of dolly simply points that further research should be done. As is much with biological science, further results usually point us in new directions and give us new questions to ponder.


In regards to idle mind, does the telemere size reset occure after meiosis has occured, or before that? Also have you heard of what molecules may be involved in upregulating production of the telomerase enzyme? I have yet to take a course on embryology...but I may still do so before finishing my bachelors.
 
proteome,

I sorry I just got the feeling you were speak of dolly as if the project was yours...
 
my experiment

I attempted to imply that it was everyone's experiment. All of us whom were anxiously waiting for the day that an animal would be cloned and wanting to experience the experiment.
 
What went wrong with Dolly was she had arthritis at an early age and developed a lung disease which was why she was put down. One of her non cloned relatives died from a similar lung disease so she may have been subseptible to it or exposed to the disease. If any of this can be attributed to the method of conception is unknown as far as I know. But there are many defects that seem likley when most animals are cloned. It is not the most polished technology at the moment.
She has a number of offspring that were conceived in the usual way, they all seem normal

A cloned creature is unlikely to have the same personality, it is always a mixture of nurture/nature.

Duncan
 
First of all Im new to the forums. A little about me, Im incredibly interested in all forms of science, but biology is my favorite, as I am a biology major. However I am by no means an expert, and the main reason I subscribed to this forum was to learn more about my passion. But anyway...

Vortex said:

Funny thing is that Charlie Chaplin at age 81 fertilised a female and the offspring was not born "middle-aged" at all.
Click to expand...

This is because while his genes were 81 years old, his sperm was not 81 years old. Sperm cells regenerate every couple days, so the cells that fertilized the female carried all his genetic information as brand new cells.
 
Welcome CrimsonMatrix

Also during spermatogenesis the telomeres are grown back

I'm Biotech/biochem dual majoring what are you? :)
 
You must log in or register to reply here.
Back
Top