Week 2: Genes are Accommodating
While it seems logical to think that gene expression is a fixed, unchanging thing, like the Rosetta Stone of human biology this isn’t necessarily the case. Genes are often viewed as sequences written into our DNA that remain unaltered through our lives, yet today we spent the majority of class time disproving this idea.
As it turns out gene expression can be influenced by many factors, one of the main being one’s environment. Different stimulus in our surroundings can have a great impact on our genes such as causing one section of the genome with specific genes to be replicated multiple times, a phenomenon known as gene amplification. Think of it as a supply and demand type situation. Genes code for proteins, which perform specialized functions; as the need for a protein goes up, our bodies respond by supplying more copies of the corresponding gene. For example, when small mammals are exposed to heavy metal (not just the headbanging kind) there is a significant increase in replication of a gene coding for a particular protein that will remove metal from the bloodstream. Conversely, sometimes it may be desirable to prevent gene amplification. Take chemotherapy as an example. Chemotherapy is generally given in large doses. This helps to prevent cancer cells from undergoing gene amplification and subsequently being able to protect themselves from treatments aimed to destroy them.
So at this point in class we’ve firmly established that gene expression is malleable. But how does this idea apply to things that are more relevant to the general population (i.e. something other than disease treatment or metal exposure)? Well there’s another mechanism in the cell that can result in the generation of genetic material, a process called gene duplication. When there are multiple copies of the same gene this means that one copy could theoretically develop a mutation and the cell would still have one functional copy. As it turns out this is one way in which new genes come onto the playing field. It’s kind of like if you have your best player bat cleanup so top of the line you have more room to experiment.
Needless to say, by now I’ve become more than convinced of the incredibly adaptable nature of gene expression. Maybe if the human genome is anything like the Rosetta Stone it at least has some extra carving space and an eraser.