I hereby resurrect the "something I learnt this week" posts. Although they are still unlikely to be weekly.
I have just been enlightened (mostly via Wikipedia) on what a transposon is. In short a transposon is a small part of DNA that can move around within the genome of a single cell. They can cause mutations and increase or decrease the amount of DNA within a cell.
The amount of DNA within a cell can be changed because some of the transposons (types I and III) copy a section of the DNA and transpose it to another location. Type II transposons don't "copy and paste" but rather "cut and paste" so the actual amount of DNA should remain unchanged1.
The fact that transposons cause mutations is one of the reasons they are exceedingly interesting. In some cases, like in corn, the mutations are interesting for reasons of simple curiosity; one effect they can have is to change the colour of the kernels. In other cases there is a much more pertinent reason why they are interesting. For example transposons are the reason why bacteria can very quickly become multi-drug resistant and diminish the effectiveness of antibiotics.
Retrotransposons (type I) are in the spotlight in finding a cure for AIDS because the HIV-1 virus behaves like a retrotransposon. Other diseases that transposons of various types are implicated in include leukaemia, haemophilia A, haemophilia B, immunodeficiency diseases, predispositions to certain types of cancer and muscular dystrophy.
- This post is the result of around 30 minutes of research on a topic I previously knew nothing about. I have almost certainly got something wildly incorrect and left out the great majority of interesting and important information. I'm clearly open to any corrections or additions you care to make. I got the majority of my information from Wikipedia and from here. [↩]