Mature Human Embryos Created From Adult Skin Cells – washingtonpost.com, By Rick Weiss

Cloning involves fusing an ordinary body cell with a female’s egg cell whose DNA has been removed. Chemical factors inside the egg reprogram the body cell’s DNA so that the newly created cell develops into an embryo that is a genetic twin of the person or animal that donated the body cell.

I’ve long had a question about cloning. As I understand the process, you take one cell (typically an egg cell), remove its nucleus and insert a nucleus from another cell, creating a clone of the cell the nucleus came from. If the cell into which this nucleus was inserted is an egg, you grow a cloned individual.

What I never hear discussed in this is mitochondria. Mitochondria are the so-called powerhouses in cells, responsible for converting fuel into energy. Oddly, mitochondria reproduce themselves separately from the more famous mitosis. As I understand it — and I’m no scientist, as may be more than obvious to one — your mitochondria all come from your mother. Which is to say, mitochondria come from the egg.

So, my clone and I are not exact duplicates. I have my mother’s mitochondria (as would my twin). He does not. Is the explanation simply that lay-people misunderstand the word ‘clone’ to mean an exact duplicate? Or do scientist simply shrug this off because — as far as we know now (the key phrase in science) — mitochondria are irrelevant to individuality? mjh