Wednesday, April 22, 2009 - 00:40
That's how new life forms are created every day in the wild, folks. Human researchers of course have added a few twists on the theme. If we can't induce bacteria or animal cells to collect new bits of DNA on their own, we turn to electroshock therapy. With plants.... aw heck, we just shoot them. And where did this crazy rant come from you ask? Last Saturday morning, at the crack of 9 am I got to be interviewed on a radio program with two of the main spokespeople from the DIY bio movement, Mackenzie Cowell and Meredith Patterson. The program was "The Food Chain" (you can listen to it here: ) Our host was Micheal Olson, a nice friendly guy, who sounded so much like Frosty the Snowman from the Rankin and Bass TV special, that I kept expecting to hear him say "Happy Birthday!" His voice was a little disconcerting, and they never did manage to list me on their web site, but it was a good time. And mostly, the whole episode made me really glad I have a blog, so I could come back to the radio show topics with better answers than I gave on the air. The whole spiel about making uncontrolled life in people's basements! Muh hah hah, got really, really tiresome. At ever commercial break we heard the question:
Should life be free for the making?Well, we don't pay to have children, so depending how you interpret the question, I guess in many ways it already is. The question we were exploring in the show was really this "could DIY'ers, working at home, create some dangerous form of life?" Maybe. But I think improperly disposing of bacteria with antibiotic-resistance genes and creating more non-point source pollution by dumping lab chemicals down your sink could present more immediate problems. As far as this question of "creating new life," if we define this as introducing new genes into a different organism, say putting a bacterial gene into a plant or a gene from one bacteria into another, this isn't an unnatural phenomenon. If biologists are capable of creating new life, it's only because bacteria and viruses taught us how. The thing is, if humans can "create new life forms" (start the eerie music and maniacal laugh track), it's only because we learned how to do this by studying the biology of bacteria and viruses. Bacteria and viruses move DNA around on a routine basis, folks. And, I came up three catchier names for these mechanisms than we normally use. I christen them: injection, collection, and sex. These aren't the normal words we biologists use, but I think they're more memorable. What do those weird terms mean? Inserting DNA via Injection Viruses pick up extra DNA from time to time from the creature they infect and then they make new viruses, who move on and infect a new host. Sometimes the newly made viruses pick up a bit of host DNA. They insert it into the new host, who survives, and keeps the new DNA. Our fancy name for this is transduction (and sometimes gene therapy). We humans have experienced this. We have all kinds of ancient retroviruses in our DNA that have probably helped to make use humans. But that's another story. Collection Some bacteria collect DNA. They pick up DNA that's lying around in the environment and sometimes find a use for it. In fact, this is how Fred Griffith discovered that DNA was the genetic material in the first place. A perfectly nice harmless version of Streptococcus pneumoniae picked up a new gene from some dead bacteria, became deadly, and killed some cute little mice. We call this "transformation." Sex This is how bacteria engineer plants, in the wild, and also, other bacteria. Kinky as it sounds, we used this mechanism quite a bit, when I worked in the lab, to move lots of DNA around between species via tri-parental matings. One type of bacteria furnished some of the pieces, another bacterium the parts we wanted moved, and a third, the host, Agrobacterium, our pal, who would put the DNA into a plant. This process is also called "conjugation." Now you know. Genetic engineering is natural and bacteria and viruses are out there creating new life. I guess you could say in nature, bacteria and viruses play God.