January 17th, 2013
1 minute read
Within our DNA are the remains of thousands, maybe millions, of genetic nomads. They once roamed free through the landscape of our genomes; now most are silenced and still, unable to move. These are the ‘jumping genes’, or ‘transposable elements’ to give them their proper name; curious stretches of mobile DNA. Almost 50% of our DNA is made of these remnants. We see them in virtually all organisms, from bacteria, insects and fish all the way through to us humans. In mammals the only active jumping genes we’ve seen are a type called retro-transposons, which scatter copies of themselves throughout genomes. Now a new DNA sequence for a different type of jumping gene, the first active example of its kind ever to be seen in a mammal, has been spotted jumping around in the genome of the brown bat.
December 28th, 2012
1 minute read
You’re not just eating for one. You’re eating for trillions. We like to think of ourselves as an individual, but the truth is we are never alone. We are a buzzing hive of bacteria and other microbes that make up our ‘microbiome’. They eke out a living in whatever niches they can find, our skin or parts of our digestive system; we are an ecosystem. Like all ecosystems there is competition for resources, and some microbes don’t take it lying down, they fight. I’ve written before about Cholera’s spring loaded dagger, but microbes have many means at their disposal, some release enzymes to chew off important bits of their competitors, or poison them. But a few go a step further; they use biological warfare: unleashing viruses to kill off the competition.