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[RC] Shoot the Clones - k s swigart

Rosalie said:


We don't have to depend on cloning to mess up the equine gene pool,
look at the AQHA horse Impressive and HYPP.  There are other
examples too.


and Ed said:


There is good evidence that the TB may have such a small gene pool
that meaningful increases in the genetic part of performance are

extremely

unlikely. The logical response would be to open the registry, and

racing,

to new genetic material.


These two statements are both good examples of why registries should be
leery of registering clones.  He HYPP/Impressive problem exists in the
Quarter Horse registry because of overuse of a popular breeeding
stallion whose genetic flaw was not discovered until there there were
55,000 horses with him in their pedigree.  Because of this the AQHA has
been battling for over a decade on how to remove this ONE gene (that can
easily be tested for) from their gene pool.  Not because the science of
removing the gene doesn't exist, but because the number of horses that
would have to be removed in order to remove this one gene is staggering.

Cloning, by its very definition is "overuse of breeding individual."

The Thoroughbred, and the limited size of its gene pool is a result of
centuries of "overuse" of breeding individuals.  And yes, lack of
genetic diversity DOES (scientific fact) lead the lack of opportunity
for genetic improvement.  As Ed states, what the Thoroughbred registry
needs to to to improve the breed is to OPEN the registry.  Registering
clones of horses in their already limited gene pool would not accomplish
this, it would limit the gene pool further.

It is interesting to me to note that in the early post stated that it
was the AQHA and the Jockey Club who have said that they will not
register clones.  Hopefully because they understand (from past
experience) just how devastating overuse of breeding individuals and
limiting your gene pool can be.

While it has been true that man has been cloning organisms for millenia
(not just since the 60s as Truman mentioned) by grafting assorted fruits
for example.  Pretty much the motivation for doing this comes under the
heading of "food production."

It would make perfect sense to be cloning horses if the intent were to
eat them.  Otherwise, the narrowing of the gene pool combined with the
overproduction of possibly genetically flawed individuals is probably
too great a risk to take.  The handful of situations where cloning could
lead to genetic improvement are greatly overshadowed by the number of
situations where it could lead to genetic degradation or stagnation.

The AQHA can't get rid of HYPP because doing so would require culling a
staggering number of horses....and this is just from ONE stallion.
Imagine how much worse it would be if somebody had cloned Impressive and
used the clones for breeding as well.

kat
Orange County, Calif.



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