As far back as 1992 mice have been created whose DNA which codes for the production of prions has been removed. These "prion knock-out" mice are apparently healthy, encephalopathy resistant, and sever the chain of prion disease transmission. Why have such cattle not been developed? In the 13 years since "prion knock-out" mice have been developed, many have been studied and thus far they have been described as normal(1) while other studies have found differences in their patterns of sleep(2) and ataxia late in life(3,4).
Mice become ataxic at 70 weeks and the proportional age for cattle is about 13 years (based on a mouse/cattle lifespans of 2/20 years). Since most cattle are slaughtered well before 13 years of age, it seems interesting to at least study prion-null cattle. Is such research being done?
The idea is immediately obvious to anyone who has heard of "prion knock-out" mice, but AFAIK it has not been baked. So I submit it to the halfbakery for a vote. Is the idea of Genetically Modified (GM) cattle too far fetched for consumers to consider? Is there no market for such cattle?
Consider the consumer, who is often informed that "specified risk materials" have been removed. This is based on the consensus in the scientific community that abnormal prions are only found in areas of the body in which prions are highly expressed.
But consumers are often not told that prions exist in the membranes of nearly all cells in every part of their (and their meal's former) body. Prions are more highly expressed in the neural and lymphatic tissues but they still exist in muscle, blood etc. Based on these facts the marketing of aprion cattle would be dead simple (generate fear of the competitors product) and may even lead consumers to pay a premium for perceived safety, of such GM cattle.
The usual anti-GM argument about preventing GM material from spreading throughout nature is not applicable to aprion cattle, as they are not often carried adrift by the wind to breed with other cattle in far off fields. Furthermore they would be provably safer with respect to causing vCJD.
Aside from the consumers, consider the slaughtering/packing industry, the entire system of testing and tracking would be irrelevant to aprion cattle, which would make processing very cost competitive.
Finally consider the producers. The farmer/rancher/feed lot owner who's had an incidence of BSE in her/his livestock. It is common practice to then cull the entire herd to avoid the consequences of horizontal contamination.
But it is apparently not common practice to abandon the property. Any cost effective decontamination of the large areas of land involved do not destroy the prions in the soil (which is the medium for transmission in the prime theory for explaining horizontal transmission as seen in purely herbivore populations).
There seems to be a market for such cattle, and the benefits of 100% BSE free cattle should be obvious.-- emaveneau, Jan 21 2005 Moratorium Genetic_20Engineering_20Idea_20MoratoriumSince this is //at least half-way feasible// I don't think it breaks the moratorium [emaveneau, Jan 21 2005] (1) http://nobelprize.o...tes/1997/press.html//In 1992 ... creating so called prion knock-out mice.// //Strangely enough, mice lacking the prion gene are apparently healthy, suggesting that the normal prion protein is not an essential protein in mice, its role in the nervous system remains a mystery.// [emaveneau, Jan 21 2005] (2) http://medweb.bham....ions/PrP_Intro.html//no behavioural or physiological changes associated with loss of PrPC..., but more recent reports revealed abnormalities in circadian rhythms and sleep// [emaveneau, Jan 21 2005] (3) http://www.mad-cow....tom/prion_evol.htmlRefers to work of Dr Suehiro Sakaguchi published on the April 11, 1997 in Nature. [emaveneau, Jan 21 2005] (4) http://www.nature.c...4/abs/380528a0.htmlAbstract of Dr Suehiro Sakaguchi's paper in Nature [emaveneau, Jan 21 2005] Lifespan/life of cattle http://www.hsus.org...nimals/beef_cattle///The lifespan of cattle averages 20 to 25 years.... typically slaughtered at 15 to 20 months// [emaveneau, Jan 21 2005] Japanese, U.S. scientists develop BSE-resistant cow for medical use http://www.hpj.com/...ientistsdevelop.CFMIs this what you mean? [FarmerJohn, Jan 21 2005] U.S. scientists create more Aprion cattle. http://www.scienced...01/070101103354.htmBaked again, but not out of the lab yet. [emaveneau, Jan 03 2007] [El Dorado Jr] The anti GM lobby has valid concerns about safety, spread of GM material and continual payment / licensing.
On Safety: The natural cattle are provably unsafe, the modification prevents the ability to get and spread the disease. GM wins.
On Spread: described in article.
On Licensing / reuse of seed / reuse of cattle: Why not avoid horrible licensing altogether? The first cattle can be created in a uni lab. The public would pay the capital costs, and the health of the population / efficiencies of processing would pay for the costs (indirectly) many times over.
Are there any anti-GM arguments I missed?-- emaveneau, Jan 21 2005 This sounds good. It would decrease the cost of destroying cattle (which Europe only does because of the export problems it would cause) and as far as I have read the articles there are no problems for humans. But perhaps further study would be wanted, just to make sure.+-- Susan, Jan 21 2005 Spread would never be a problem. The breeding of cattle is carefully controlled and selected, cows are unlikely to breed randomly and spread their seed on the wind to root in fields miles away. This sounds good to me.-- wagster, Jan 21 2005 [Susan] Thank you for agreeing it at least deserves study.
//It would decrease the cost of destroying cattle// Once bitten twice shy.
Although aprion cattle have many benefits, rendering their remains and feeding them back to cattle would be a political bomb which no one would attempt.
Ignoring the political impossibility, let's assume Europe allowed Aprion Cattle to be fed to Cattle (AC2C).
The science indicates that a complete lack of prions make it impossible for the cattle to get/cause BSE.
So Europe would have a strong case in the WTO against any nation which tried to block exports from Europe from fears of a rule change allowing AC2C.
So the status quo of the export markets should not change by allowing AC2C.
But it would be impossible for politicians to sell. At most aprion cattle would be treated like all other cattle and destroyed, simply to avoid a feed back loop.
On the other hand, let's look at countries in which cattle parts are still fed to other animals which, in turn, are then fed to cattle AC2O2C (US, Canada). These countries monitor the feedback loop and weigh the risk against the reward. Allowing AC2O2C would lower the risk of BSE.
Politically there would be no downside for allowing aprion cattle to be raised and treated like other cattle. Inaction leads to status quo, allowing aprion cattle reduces risk of BSE.
Incidentally some export markets of US and Canada are demanding each cow be tested for BSE. With aprion cattle the tests are not needed (would you test a cow with no legs for a broken leg?) thereby lowering the cost.-- emaveneau, Jan 21 2005 //Although aprion cattle have many benefits, rendering their remains and feeding them back to cattle would be a political bomb which no one would attempt.//
I didn't mean that the aprion cattle (the ones with the possibillity for BSE, right?) could be fed back and thus reduce costs. I meant that it would save us from having to destroy cattle that hasn't been infected at all but have to be because the disease was found in adjacant counties. So that would be an even bigger plus.-- Susan, Jan 22 2005 I'd like a shot 'the serum, please. Way better than starving to death.-- reensure, Jan 22 2005 Ah, that would be the 'non-scientific' way...-- Susan, Jan 22 2005 I think you need more than two, otherwise it would be sort of scandalous next generation.-- tiromancer, Jan 22 2005 [FarmerJohn] Thank you for the link. It looks like the idea is baked. I'm surprised that the costs outweigh the benefits.-- emaveneau, Jan 23 2005 random, halfbakery