Great Grey Horned Owls, you beasts should really not sneak up on people! In the light of my porch you shaved lemurs — what with your random tufts of hair and beady little eyes — look quite terrifying. Quite.
I suppose I did promise to start our talk about cloning this evening, but frankly I’m surprised that the coconut you call a frontal cortex managed to remember our appointment, let alone the directions to my new lair. You were careful to not be followed, weren’t you? Still having some problems with the authorities, don’t you know. Hoo . . . “Authorities?” Funny that such feeble creatures would proclaim to have authority over me. Have you also declared yourselves lords of the sun?
Anyhoo, best start now, and rid myself of your horrible presence sooner rather than later.
You see, to create a clone, first you need something to clone. Are you following? It is very hard to tell sometimes; one might mistake that blank expression on your faces for some sort of neurological collapse.
Sounds simple, doesn’t it? Just need to find something to clone. But it isn’t all that simple . . . for you see, all DNA isn’t created equal. Not every cell in your body needs every scrap of that big 46 chromosome-large genome of yours. So, to make things easier on the machinery — which uses your DNA to create proteins and whatnot — the unused bits tend to get very tightly wound, leaving the useful parts nice and exposed for the ribosomes to come and transcribe. This way proteins that are needed can be quickly assembled, since the ribosome need not spend valuable milliseconds searching the entire chromosome.
What does this mean for our cloning efforts? Well, if you were to extract DNA from any old cell, without any consideration for what parts of those chromosomes are being used, you probably won’t end up with a viable clone. Not that one could tell the difference between you rabble and a failed science experiment.
Sex cells won’t do either, for two reasons. First, sex cells only contain half of your DNA, or 23 chromosomes, since the other 23 is supposed to be provided by your partner during the act of . . . Hoo-aaaaack!
My apologies to those of you in the front row; the very thought of your species mating is enough to make me physically ill. Shame; that was a rather tasty mouse. Don’t let those scraps go to waste, now.
Where were we? Oh yes, the second reason why you can’t use sex cells to create a clone is because their DNA has been all muddled up, through meiosis, the process through which sex cells replicate. You see, to maintain genetic diversity in your population, when germ cells — the cells that divide into sperm or ova — are created, their 46 chromosomes, which consist of 23 from your mother, and 23 from your father, swap DNA randomly so each of the chromosomes passed on to your unfortunate offspring is a medley of your mom and dad’s DNA.
So you see, if we were to make a clone from a sex cell, it would be incomplete, and not so much a clone as an artificially created offspring.
No, if you want an exact duplicate you need to find what are called “undifferentiated cells,” or cells that really haven’t become anything, such as a liver cell, yet. While these “stem cells” can be found in several major organs, they really only exist in great enough numbers to facilitate harvesting from bone marrow.
Once you have some bone marrow cells, it’s a simple matter of extracting the DNA. Well, simple for me anyway. For you, the act of extracting DNA would be tantamount to soaring like a bird, something no human can do without piles of expensive equipment and training.
Now be gone! My forcibly vacated stomach craves mammal flesh, and the smallish human toward the back has me salivating something fierce. Lucky for you, I have another mouse in the fridge, but I might not be able to resist the succulent taste of hairless ape for much longer.
