A little more than three years ago I wrote the article The Long Road ahead of the Human Genome Project, in it, among other things I said: “The raw result (of it) could be compared with a book that gives you a highly detailed description of every single part of your car. You will have signposts telling you where each part's description begins, but in the majority of the cases you will not know which part it is. Obviously you still will not have the slightest idea as to how your car (the human being) functions. Neither will it tell you how the piece (gene or control region) looks like when it is broken.”
Before continuing, I must tell you that you'll find most of the technical words that I use here, in the ="http://www.ncbi.nih.gov/About/primer/ind..."> primer by the National Center for Biotechnology Information.
As soon as I finished writing that phrase, I asked myself: How are they going to know how does it function? You and I are the product of the functioning of between 30,000 and 40,000 genes, not all of them at once of course. Depending on the type of cell, the time of the day, and if you are a developing embryo, the amount of genes in action will vary. It is interesting that when I wrote that article it had been believed for more than 40 years that there were at least 150.000 genes.
On the other side, genes are static sequences of DNA; they function through the mechanism of gene expression that consists in reading the messages encoded in them. A process that ends up in two types of molecules, either RNA or protein. Being a biochemist I knew that the mayor cell's molecular effectors are the proteins, then the only way to “see” the genome at function, will be to “see” the proteins in action.
