Clones and Eternal Youth

I have a limited knowledge of how genes work. So, I'm going off of my basic understanding for this.

The most important question in the subject of clones and eternal youth used to be "what makes us age?" We have the answer to that, and in the answer we found out why clones die early and other such information. What I'm going to say relies heavily on this, so I need to detail what we found.

At the tail end of the molecules which make up our genes is a random bunch that don't mean anything. As our cells replicate using those strands of DNA, the tail end that means nothing slowly disappears. When that end is gone, the molecules which make up the important bits of our DNA start to disappear. When the brake-down becomes too much for the body to handle, the person dies.

The issue with cloning is that when we make a clone from an adult, the tail end of DNA which determines how long the clone will live is the same length as the adult its cells were taken from. To fix this, we need to either make our clones while the original is still just a few cells. Or, we can take one of those cells from when the original is really young, and store what the sequence is. Then, we can use gene therapy to add the missing bits before making the clones.

Here's the point. If we can figure out how to extend the length of the tail end of the genes which belong to someone who is already alive, we can have the fabled eternal youth. We can also make clones which do not die too soon. I think the first thing is to see if the tail end has to be something specific, or if it can be anything. If it can be anything, we can just make a sequence to throw on there. If we can figure out how to make it, we won't even need to try to harvest cells from a fetus.

My guess is that there are a number of different sequences which will work for each species, but that only closely related species will be able to use the same sets of sequences. But that's not for me to figure out.

Why did I feel it necessary to point this out? Because I believe I remember people saying that they need to figure out how to stop the loss of the tail, instead of figuring out how to add more to the tail as it disappears. And I realized that the same technology which allows them to make rats glow using genes from a jellyfish would allow them to insert more "tail" on the genes.