Re: I'm doind a speech on cloning. Can you could use animal cloning for food?

Hi Andrew,

These are very important questions about a topic that will affect us all.

Animal cloning for organ transplant:

This is a potential application for animal cloning.  Two of the major problems with 
organ transplant are 1) Lack of donor organs, and 2) rejection of the donated organ 
by the patient’s immune system.

If animals could be used as a source for donor organs, that could alleviate the first 
problem (although such a practice would certainly raise the objections of the 
animal rights community)

Rejection of a donor organ occurs because the recipient’s immune system does not 
recognize the organ as part of the body.  The immune system views the organ as 
an invader, and does its best to get rid of it.  How does the immune system know 
the organ does not belong?  There are protein and carbohydrate molecules on the 
surface of the organ that vary from person to person, and the immune system learns 
early on what kinds of molecules are present on the organs of its own body.  This 
can be a problem even when the donor organ comes from a close relative.  

It is possible, in theory, to genetically engineer an animal in such a way that its 
organs display molecules like that of humans, or so that they lack the proteins that 
would alert the human immune system. In fact, researchers are working on this very 
thing, and you can read a bit about it at:
 http://www.wired.com/news/medtech/0,1286,49450,00.html?tw=wn_story_related http://www.abc.net.au/rn/science/ss/stories/s955888.htm

Part of this process would involve cloning, but once suitable animals have been 
made, it is likely they would be propagated in the traditional way.

Plant cloning for more food:

This is not only possible, but has been practiced for a very long time.  Plant 
breeders can work for a very long time to develop a new kind of plant, say a new 
variety of apple.  The problem is, many fruit trees won’t “breed true”.  In other words, 
if you plant the seeds from a Granny Smith apple, you will get apple trees, but the 
apples from those trees will vary quite a lot, and most of them won’t be exactly like a 
Granny Smith, and many of them won’t be as productive.  So if a plant breeder gets 
a really great new apple tree that makes a lot of great tasting apples, how can they 
make more of those trees?  By cloning the tree.  For most trees, this is a fairly 
straightforward process, as they can be propagated from cuttings.  Frequently the 
cuttings are grafted onto a good rootstock, which has also been propagated by 
cloning.
In agriculture, this “old fashioned” way of cloning is done mostly with fruit and nut 
trees and bushes, and has allowed the widespread propagation of the most 
productive varieties.

Annual crops, like wheat, corn, rice, and soybeans are not amenable to grafting.  
Even if they were, no one would bother to use this as a standard method of 
propagation because it is much easier to plant acres of these crops by seed, and 
each plant only produces a small amount of food for one year.  However, these 
plants can be modified by genetic engineering, which would involve cloning, and 
then propagated in the normal way (by seed).

So far, traditional breeding is still the most effective way to improve yield potential of 
annual crops, but it is very likely that genetic engineering, and therefore cloning, 
will someday make contributions to increasing potential yield.  In the meantime, 
several genetically engineered versions of these crops are being used.  The most 
widespread of these are modified to resist insect damage or to resist an herbicide 
that the farmers use to kill weeds.  In both cases, the modifications are intended to 
make it easier and cheaper for the farmer to grow the crops.

Cloning animals for more food:

This is a very reasonable possibility that many animal breeders are interested in.  
When animal breeders get, for example, a champion cow or bull or pig that has 
very desirable qualities for food production, they do not have the option of 
propagating by cuttings the way some plant breeders do.  Instead, they have to 
breed the animal to another, and hope that the good qualities show up in the 
offspring.  Sometimes they don’t, but sometimes they do, and this strategy has been 
quite productive.  However, the results could be much more consistent of the 
animals could be propagated by cloning.  Furthermore, a champion cow can only 
produce offspring at a very slow pace.  This could be sped up if the cow could be 
reproduced by cloning.

Alex Brands
Lehigh University