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Given the state of the art of gene sequencing, any skilled practitioner can determine these sequences.

That's easier said than done. To find a mutated gene that may be critical for the development of, say, cystic fibrosis, you have to know where to start looking. You have to develop tools to look for it. You have to demonstrate that the mutation causes loss of function or altered function. This is often done using C. elegans, Drosophila, or mouse models and then, once a candidate gene has been identified, you start looking for something similar in the human genome. In the case of ric3, a protein believed to be the first ACh receptor specific protein required for the maturation, release, and delivery of the nicotinic acid and related receptors. It was discovered by doing a screen of mutants of C. elegans that were resistant to the inhibition of cholinesterase (hence "ric"). There was a C. elegans mutation of a neuronal ACh receptor that could not shut off the nerve impulse. These animals twitched and jerked until they died. Looking at a number of these animals expressing other mutations, one was found that did not twitch itself to death even though it expressed the mutant AChR gene. It was found to have a mutation in another gene, later called ric3 (because there were a variety of ric genes), that was found to be required in C. elegans for the maturation and delivery to the cell surface of the AChR. The mutation in ric3 blocked the delivery of the mutated AChR protein and, so, rescued the animal. This is important because the maturation and folding of the multi-subunit neuronal nicotinic acid (and acetylcholine) receptors is a very time consuming and inefficient business and there had not been discovered up to that point a specific chaperone protein to help in the process. Some people suspected Bip or calnexin but it had never been conclusively demonstrated. Once this protein was discovered in C. elegans and the gene sequenced, similar sequences were searched for in the genomes of other animals and, lo and behold, virtually everything with a nervous system appears to have some form of ric3.

The point is that you have to start somewhere with some actual problem and then work into it to discover the genetic component. It's not a trivial business. I spent a couple of years on this with a boss who wouldn't publish each result as we went along because he wanted a "more complete story." So now a bunch of other people have papers publishing what I had already discovered. Of course, there's one biggie that no one else has noticed that has pointed in a completely different direction. Now that I'm out of that lab, we'll see whether I get on that paper we were working on when another post-doc took over the project (first year post-docs are way cheaper than 5th year post-docs).