Irene’s comments on DNA

I am extremely fascinated by the human genome. It started back when I was in high school biology, and we were first learning about the concepts of a genome, chromosomes and genes. Of course, at that point the knowledge presented to me was very basic, but one thing always stood out. We were taught that 99% of the genome is “junk DNA,” meaning we haven’t discovered a function for it, so it must not be important. To me, it was ridiculous that anyone could even begin to believe that this was true, but low and behold, every textbook I checked said the same thing.

Another big shocker came at the beginning of the millennium when the first human genome was sequenced, and scientists discovered that we overestimated the amount of genes we have by oh about 100,000 or so. In reality, we don’t have many more genes than say a worm or a fly. It turns out that most likely it’s the regulation and expression of said genes that makes us humans and not worms, but at first I think that news humbled everyone a little.

In just a few years we have made huge advancements in beginning to decipher the genome and how it works, however many have come to realize that we are just starting to shave ice off the tip of the iceberg. Every single one of our cells (except red blood cells, which don’t have a nucleus) contains a copy of a code (that we hardly understand) capable of producing a complete human being and controlling our entire development, life, and decline. Trying to understand such a system, to me, is incredibly fascinating. So, via graduate research, I decided to work on trying to figure out what some of that “junk DNA” does. So far, it turns out that most of it is pretty important.

3 thoughts on “Irene’s comments on DNA

  • 1/9/2008 at 2:46 pm

    Is it also true that different cells in our body can contain different genomes? I think I heard that somewhere.

    At work, I am building this visualization tool that will allow you to view the unique dna sequences inside a certain gene or subset of a gene, across an evolutionary tree. By identifying unique patterns, the idea is to use this tool to identify what makes a cow a cow, or what makes a mammal a mammal, or what makes a life a life (if we figure that one out, we write a paper on it and win the Nobel prize). It’s all very complicated and I don’t really understand it. I just make computer graphics.

  • 1/9/2008 at 4:33 pm

    “junk DNA” sounds like garbage to me too. There’s not one cell in our bodies that doesn’t have an express purpose. Good luck with your research.

  • 1/9/2008 at 5:56 pm

    This could be true, but on a technicality. For example, if a cell in your body decides it wants to be on its way to becoming a cancer cell, it may acquire some mutations in its genome that change the way some genes are expressed so that it can divide faster and more aggressively. Then, that cell would have a different genome than your other cells.

    That’s different than a mutation inherited from your parents. In that case, every cell in your body would have that particular mutation.

    Another way your question could be true is if you’re talking not about the genome itself, but something called the “transcriptome.” That basically refers to all the genes that are transcribed from a particular genome in a particular cell, resulting in either a brain cell, a heart cell, a nerve cell, etc. Each type of cell has a unique transcriptome.

    The project you’re working on sounds awesome! Science is definitely moving toward a bioinformatics world. I’ll keep my eyes peeled for your name in the journals.


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