
Tuberculosis-resistant cows developed for the first time using CRISPR technology - upen
http://sciencebulletin.org/archives/9946.html
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jfarlow
Cows have a protein in their white blood cells helps to make nitric oxide (a
molecule very toxic to bacteria, including tuberculosis). It has been shown in
other instances that if you have more of the protein (NRAMP1), then you tend
to be more resistant to tuberculosis, and less of the protein, then you are
less resistant to a tuberculosis infection. The protein itself is a
transmembrane iron transporter. It just shuffles iron from one side of the
membrane to another.

Cows already have the dna that encodes for NRAMP1, but in order to demonstrate
their prowess with CRISPR technology, this group found a dormant location in
the cow's genome in order to insert DNA that encodes a second copy of the same
protein. The expectation being that by having a duplicate copy of the DNA that
encodes for the NRAMP1 protein, more of the protein would be produced, and the
cows would be less susceptible to tuberculosis. This seems to have been the
case.

So here, adding DNA encoding a protein that already existed in the cow's
genome allowed _more_ of the protein (NRAMP1 - an iron transport machine) to
be produced, thus conferring some tuberculosis resistance by means of allowing
the cows white blood cells to produce nitric oxide more efficiently.

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pmoriarty
Related article:

[http://gizmodo.com/the-fda-is-cracking-down-on-rogue-
genetic...](http://gizmodo.com/the-fda-is-cracking-down-on-rogue-genetic-
engineers-1791760888)

 _" Ishee was preparing for a project that sought to cure hyperuricemia in
Dalmatians—a common liver malfunction that frequently results in kidney
stones, bladder stones or gout.

"It should be straight forward," he told Gizmodo. Ishee plans to use the gene-
editing technique CRISPR to correct the single errant nucleotide that causes
the condition, reversing the mutation to turn a T in the genetic code back
into the correct G. Then he'll use a technique called sperm-mediated gene
transfer, which will allow him to transfer his engineered Dalmation DNA to a
female Dalmation, resulting, he hopes, in a fertilized egg that'll produce
hyperuricemia-free pups.

"The animals just get molecular surgery to fix a broken gene that causes their
bladders to explode," he said. "Then those animals can become the founders on
a healthy generation of Dalmatians and breed the disease away in a few
years.""_

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legulere
If it's such a simple genetic flaw, why isn't marker assisted selection
breeding used to eradicate the problem? Such a thing could even easily be
mandated by law.

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gozur88
It might be coincident with desirable traits.

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jessriedel
Tangent: This is nice popsci reporting. Reasonable, not very hyped,
contextualized laymen explanation of a technical paper, with a link at the
bottom direct to the source.

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daemonk
One interesting thing about what they did was they assayed potential insertion
sites with ChIP-seq to see how much off-target effects there are. They used a
catalytically inactive cas9 for IP to see the quantity and strength of off-
targets.

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guard-of-terra
While they're at it, they might also make milk not burn-prone.

I've read there's a single base that makes cow's milk to behave like that.

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jfarlow
Do you happen to know which protein?

~~~
guard-of-terra
β-Lactoglobulin.

