RE: Paper discussion #4 – The Cloning Revolution
When you are doing experiments you want to have one variable parameter. All the other parameters should stay constant so that whatever you measure is due to the change of that one variable parameter only.
technically yes, but there's a problem here too. If all animals you test a compound on are clones, they might be the carrier of a single gene that causes a different reaction.
So if you're unlucky, u'll draw completely wrong conclusions.
The main reason why we have to use so many animals during a study is that we have to vary the genetic material. Having 100 identical animals is a biological n=1, and you end up with only technical replicates.
I'm sure there are types of studies where you want to exclude genetic variation. In pharmacology/toxicology though, we need it.
Edit: By the way, very good post, I enjoyed reading!
Good point! I agree that for some studies the genetic variation is valuable in itself.
Although, when you are doing these studies, is the genetic variation the variable parameter or is dose as well? For example, in a pharmacology study with 100 monkeys, do you use the same dose to test the average effect of the drug on a large variety of genetic makeup? I would argue that testing dose-response testing would benefit from cloned subjects.
Additionally, I predict it would be possible to prescreen the DNA-to-clone for a gene that can cause substantially different reactions. Although, this is purely hypothetical.
Great input @sco!
when you vary the dose, you take groups of animals that receive the same dose. You're right, with clones you would probably need much less animals here. But even so, you would have to test at least one concentration with different animals in addition to that, lest you risk the effect described above again.
But this could - in the end - result in less used animals, depending on the design of the study. Great thought!