knock out genes screening need help

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Biolink
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knock out genes screening need help

I’m asked to design methodologies pertaining to create a cat that will not cause allergic reactions in cat-lovers. I’m provided with the information about cloning the gene encoding a protein found in cat saliva, expressed the protein in bacteria and should show that that it causes violent allergic reactions in people. But what hits my mind is that if i succeed in making a knockout cat lacking this gene, anyone who buys one will easily be able to make more hypoallergenic cats just by breeding them. So Im asked to design methods to prevent it, and me and my friends discussed and came out with the flowing methodologies,
(a)        Injecting the modified ES cells into embryos that have a genetic defect that will prevent the mature adult from reproducing.
(b)        Implanting the injected embryos into a female cat that is sterile due to a genetic defect.
(c)        Selling only the offspring from the first litter of the female cat implanted with the injected embryos.
(d)       Surgically removing the sexual organs of all the knockouts before you sell them.
(e)        Selling only male knockouts.
My question here is that which of the above methods will ensure that people will always have to buy their hypoallergenic cats from me? Im so confused and all my friends says different options, can anyone help me to choose the best option out of the five we submitted in order to write in our conclusion.

Ivan Delgado
Ivan Delgado's picture
 

 
This sounds like a very commercial question and not necessarily the simplest way of developing a hypoallergenic cat. My first thought would be how to easily maintain a colony of cats so that I could generate enough of them to supply the likely high demand for such animals. I am going to go on a limb and assume that the hypoallergenic cat is not going to be very healthy since you are removing something that likely provides it with some kind of protection. So working directly with such an animal would not be very efficiency (cost-effective)
My suggestion would be to use the Cre/loxP system. Generate a transgenic cat the expresses the Cre gene. You maintain this one as a separate population. Then you insert loxP sites at both ends of the gene you want to delete in a second cat. You maintain this second cat as a second population. When you are ready, you take one cat from each population and cross them. The resulting progeny will contain both the Cre gene and allergic-causing gene flanked by the loxP site, which basically means that all these progeny will lack this allergic-causing gene since Cre will cause the excision of the loxP site, along with everything in between (the allergy-causing gene). Every time you want more hypoallergenic cats, you just cross cross cats from each population. The people that buy your cat will not be able to recreate this hypoallergenic cat because any cross between it and another cat will bring in a wildtype copy of the allergy-causing gene (not as simple as that, but pretty close ;) ).

Biolink
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Thank you Ivan for your

Thank you Ivan for your interest and im really so proud of you as you explained a new strategy in some minutes, but it took so much time for me to drawout the five methodologies i submitted. The problem with me now is that i cannot incorporate any new methodologies inside my rpoject, this is bascillay an imaginary project which my professor gave to test whether we understand the concept and to test whteher we are in a position to design a project on our own. Well, me and group of my friends discussed and came out with this,now i would like to know which option among the five i submitted do you think can be used to ensure that people will always have to buy hypoallergenic cats from me as per my project. I just thought we studnets hold different options and would like to hear from you people involved in research who could select better option and can give perfect justification. Expecting your view. Kindly leave your view with justification please. Like you if others too say their view i can justify my project. Thank you once again IVAN.

Jon Moulton
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Biolink wrote:

Biolink wrote:

Thank you Ivan for your interest and im really so proud of you as you explained a new strategy in some minutes, but it took so much time for me to drawout the five methodologies i submitted. The problem with me now is that i cannot incorporate any new methodologies inside my rpoject, this is bascillay an imaginary project which my professor gave to test whether we understand the concept and to test whteher we are in a position to design a project on our own. Well, me and group of my friends discussed and came out with this,now i would like to know which option among the five i submitted do you think can be used to ensure that people will always have to buy hypoallergenic cats from me as per my project. I just thought we studnets hold different options and would like to hear from you people involved in research who could select better option and can give perfect justification. Expecting your view. Kindly leave your view with justification please. Like you if others too say their view i can justify my project. Thank you once again IVAN.

Do the knockdown with an oligo.  They don't have to buy hypoallergenic cats from you, they can use any cat they have at hand -- but -- they have to buy an oligo booster from you every three months or so.  Vivo-Morpholinos might do the trick.  I think that's a more commerically attractive strategy.  But then, I sell the oligos.

Ivan Delgado
Ivan Delgado's picture
 

 
I like jonmoulton's idea because it uses a great business model: repeat business. If you sell a transgenic organism it is a one time sale. If you sell a solution that requires multiple applications you generate a stream of revenue. 
But to answer your question, here are my views on your different options: 
a. This would work since the organism would not be able to reproduce. The problem with this is that generating the embryos that are not capable of reproducing is a genetic nightmare (maintaining the population of such an embryo is not hard but it requires more than just maintaining your typical colony)
b. This will not work. Injecting the embryos into a sterile female would either result in no progeny, or the progeny would be more than capable of reproducing so your client would be able to breed the transgenic cat and you are out of business
c. Same as b. If you sell the offspring you are giving away the transgenic animal, which can reproduce and generate more transgenic animals
d. This kind of works since common customers will not be able to generate more cats the natural way. Yet anybody with enough knowhow and good laboratory resources would be able to isolate cells from this cat and use them to generate more transgenic cats. Not easy, but possible
e. Would not work. You could breed the male cat to another cat and get more transgenic cats. Some would not be transgenic and some would; you could just select which ones cause allergies and which ones did not.
Good luck

Chuck Miller
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 I agree that a, b, c, and e

 I agree that a, b, c, and e will not work. Option d will, and if someone has the knowhow to clone new cats from an infertile one then they will probably not need your knockout cat in the first place. The oligo knockdown approach might work, but this will cause a reduction - probably not elimination - of the allergenic protein. I suggest adding a second modified gene that can be turned on or off with a drug (e.g., see Tet on/off systems) to regulate reproductive development and fertility--an estrogen receptor for example. Only you would know what gene is turned on to restore fertility and the drug needed to do it. 
 
Best,
Chuck

Revenga
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As someone who has severe cat

As someone who has severe cat allergies, let me just say that this is a disgusting conversation ...the primary concern of research scientists should always be helping humanity ... not finding ways to create a product from research and corner the market on it (or weaponizing discoveries, although that's a seperate discussion) ... you all should be ashamed of yourselves ... if you need money, push your governments for more funding for basic research ... don't withhold needed innovations in the pursuit of profit ...