[ExI] biology question please

[spike]

Perhaps I could find this answer somehow on Google, but I know we have some
biology hipsters here, Anders and several others.

 

I have been thinking along the lines of the
every-cell-a-3Giga-yr-old-organism notion.  I don't know, but I have a line
of reasoning that leads to a startling conclusion.

 

1.        Stem cells create new tissue at the site of an injury, such as a
scar on the skin or at the interface between damages surfaces of broken
bone.

2.       The stem cells get to the damage site by some means.

3.       It must be they are carried there by the blood.

4.       So there must be stem cells in the blood stream always.  So far so
good?

5.       Sperm regenerates constantly.  Reasoning: I have been losing those
things regularly for a lot of years, yet have never run out.

6.       Like any other cell, sperm must come from stem cells.

7.       I would assume one particular stem cell becomes one particular
sperm cell.

8.       The stem cells must get to the testes from the bloodstream.

9.       Tissue from a donor, with unmatched DNA, can be incorporated into
the body of a recipient, such as a transplanted kidney, for instance.

10.   If a patient receives donor blood, that recipient is getting a bunch
of donor stem cells as well.

11.   If a patient needs blood and receives a unit, at least for a short
time the number of stem cells in the bloodstream of the recipient may reach
10% or more from the donor.

12.   Some fraction of these would make their way to the testes, and create
sperm cells with the donor's DNA.

 

If this line of reasoning holds, and I can't think of any reason why it
wouldn't, or any step in the above line of reasoning that is incorrect, then
donating blood introduces some chance of the donor having biological
offspring, having never actually copulated.

 

spike 

 

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