genes, pseudogenes and the increasing complexity of the genome

Research into the human genome has led us to understand that our DNA is very complex. The genes that make us who we are are encoded in our DNA. That is straightforward, right? The research that has taken place since the genome was sequenced 10 years ago has redefined what a gene really is.

In order to have a functional product from the DNA, the gene is transcribed from DNA into messenger RNA (mRNA) and then translated into a protein, the functional element in the cell. The simple (old) definition is that a gene is a made up of several parts, a coding region that holds the sequence for the protein that will carry out the function of that gene, a promoter region that controls how the gene is turned on and off and is usually found just in front of the coding region, and a third region called the 3’ untranslated region (3‘UTR) that controls how long the RNA will exist in the cell. There may be other control elements that determine if or regulate how a gene is expressed including enhancer regions that “enhance” the transcription of the gene in to RNA, but in essence, what constitutes a gene was easily defined. There was “extra” DNA that didn’t encode a gene, however, and this extra sequence was essentially useless. It didn’t have a role and was garbage or filler. It is unimportant.

Now, after 10 years of genomic research, some of the complexity of a gene has been realized. The “unimportant” sections of DNA, in turns out, are important. The definition of a gene isn’t so simple. Besides genes that code for proteins, there are pseudogenes that are the same sequence as genes but work to prevent the activity of the gene. Some genes, depending on where the sequence for them starts and stops, can produce many different proteins that have vastly different functions. These are called alternative stop codons (aka sites) and they can produce longer or shorter genes and lead to dramatically different functions!

Together all this means that there is more regulation of genes than previously thought! Our cells, and bodies for that matter, are extraordinarily complex. Each system has been finely and precisely coordinated to control how it works. This also means that there are new avenues that can be exploited for therapy. Now that new entities have been identified, novel and innovative ways to prevent or increase their function is being investigated. This could lead to a new therapy and hopefully will reduce unwanted side effects.