Nelson – gene expression

We all know we have genes. The Human Genome Project has now revealed that humans have about 30,000 genes in their genome, that is their constellation of genes. Many people think that genes are just static, but in fact, genes turn on and turn off at different points in development. A classic example of course would be puberty. The genes that regulate pubertal development don’t get expressed until 10, 11, 12 years of age. There are some genes that get turned on at one point and turned off at another. But then there is an interesting phenomenon where gene expression, that is, how a gene reveals itself is influenced by experience. So we do know that if, for example, you experience a very stressful situation, I don’t mean a test, but something very, very stressful – loss of a parent or something like that, in that immediate period there’ll be a set of genes that will express proteins that will in turn affect brain function. And that’s another way to think of gene expression. So by expression I mean at one level, at the molecular level the expression of proteins, at another level they express themselves in changes in behavior we refer to that as the phenotype, the behavioral expression of the gene.