I've recently been catching up on podcasts, especially in the areas of my biochemical interests. There was an interesting episode from Nature's Neuropod podcast in October 2011.
Now that we have sequenced the human genome, we can now map the genes. It turns out that there are about 24,000 genes, but there are 100,000 proteins in the brain. This means that gene expression, how a gene is translated to a relevant protein can and does change in both location and time. In other words one gene can code for at least 4 different proteins which can change over time.
Studies have shown that there are huge changes in gene expression in the brain pre-natally, and post- natally, decreasing until we are about 40, then increasing again as we get older. This is an element of switching genes on and off, but far wider in implication. It kinda dents the gene expression mechanism outlined by Crick and Watson and although the podcast didn't mention it, I can imagine one mechanism whereby the transfer DNA, which codes for specific amino acids to build proteins from triplets in the coding of the bases in the DNA, somehow vary with time.
However, this is just the brain – other cells and organs have their specific proteins too, so an individual gene may code for far more than just 4 proteins. Since most of our genetic code is identical to not just other primates and mammals but birds, insects and even bacteria, and hence similar and often identical biochemical pathways, it follows that most of life will have a similar array of different gene expression in both location and time.
Thus when we play around with genetically modified organisms, including transgenic species, we are modifying only one of many possible gene expressions within that GMO cell, organ and species, which can also change with time, and hence we have no idea of the full effects of modifying or splicing an individual gene over time, or what effects those other gene expressions may have on the organism, the food chain, or humans. What we are changing is only perhaps one of a dozen or more effects, and we have zero idea of the effects of the majority of effects those expressions that a gene codes for.
Unfortunately, we have now released myriads of GMOs into the environment and it is too late if they turn out to have adverse effects in the future. But it means that until we fully understand all of the gene expressions for a particular gene and species, we are at risk of releasing something dangerous in the environment that we are not only unaware of, but also not looking for the effects of, so further GMO releases should not be undertaken until this understanding is further developed.
Of course GM is driven by big business and pharma for profits, but we need to rein them in until this research is done. It is never good to play around with nature when you don't fully understand it, and human experience shows that we always mess up: DDT, pesticides, drug resistance, MRSA, releasing non-native species to areas and others are huge reminders of our weakness in messing with our environment.
Science today is moving far faster than our ethical and moral considerations are advancing or being debated. Partly it is due to a lack of scientific and technical education amongst politicians and business leaders, both groups not well known for their high moral and ethical standards in the first place!
Releasing GMOs in to the environment is not something that can be reversed and has the potential to change natural selection and evolution in ways we can't imagine, and this release should not be governed by profit motives, but informed scientific debate and ethical considerations.
Nature Podcasts
http://www.nature.com/podcast/index.html
October 2011 Extra
http://www.nature.com/neurosci/neuropod/archive.html
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