Sex Selection in Cloning

October 20, 2009 2:28 PM

Is it possible to choose the sex of a cloned mammal or do you have to create a clone of the same sex at the animal being copied?
posted by zzazazz to Science & Nature (3 answers total)

IIRC, current cloning is accomplished by taking the whole nucleus from the original animal and transplanting it into a de-nucleated ovum. So no, you're limited to keeping the same sex.

In the future, it may be possible to do change the sex, but only from male to female. If you're using a male as the template, you could remove the Y, then take an extra cell, extract the X chromosome and use those as your XX pair. If you're using a female as the template, you have no Y chromosome material to start with.
posted by chrisamiller at 2:33 PM on October 20, 2009 [2 favorites]

Two more things:

1) Details on the cloning process are covered fairly well on Wikipedia. The exact term you want is somatic cell nuclear transfer

2) Whether the sex change I describe above is really cloning is sort of a matter of semantics. The genetic material wouldn't be 100% identical, because you've removed the Y chromosome, but all autosomes would be identical.
posted by chrisamiller at 2:37 PM on October 20, 2009

It's not impossible to have opposite-sex clones. In a naturally-occurring example of human clones, there was a case of identical triplets in Italy, two boys and a girl. The girl had lost the Y chromosome, early in development, but after the three had split from one another. While the boys' sex chromosomes were XY as is usual, the girl had XO (normal females have XX). Unfortunately, the XO genotype causes sterility, so you wouldn't try to do this intentionally.
posted by Ery at 5:35 PM on October 20, 2009