So, we talked in class today about transposons. For those who don’t know what they are, I’m going to give a brief description. For those who usually stop reading by now when I start talking science, keep reading ’cause there’s a relatively important point toward the end that warrants discussion…
A transposon is also known as a “jumping gene.” They are pieces of genetic information that can code for the machinery to either copy itself to another location in a genome, or even excise itself from one location and move itself to another. Cool, eh?
Well, think of it this way. Let’s say a transposon lands at some location in a bacterial cell that’s pretty close to a gene that codes for tetracycline resistance (that’s an antibiotic…). Let’s say another transposon lands on the other side of this resistance gene. Now, what you have is a bigger transposon that, at either side, can cut itself out and move the whole thing (including resistance) to another location, or replicate itself.
Why is this bad? Well, that’s one easy (and scary) way that antibiotic resistance is spread between bacteria. Apparently, for example, there’s a transposon in the fruit fly that is found in all fruit flies…but wasn’t there 50 years ago…so within a span of 50 years, all fruit flies on Earth got this gene. Do you know how fast bacteria divide? It’s insane to think of how fast bacteria can get these “jumping genes” and then become resistant to all of our antibiotics.
Know what else is bad? And this is the point of the discussion… The government is more concerned with developing defenses for smallpox and anthrax than they are about protecting us from resistant strains of flu, or pneumonia, etc. How many people do smallpox and anthrax kill every year? Not that many. Now, flu and pneumonia (etc…)? How many? Lots. And those guys aren’t resistant to all of our antibiotics…yet…
So yeah, at this point, it’s likely that within the next 20-30 years (or sooner?), all of our current antibiotics won’t be effective against common ailments that are curable today. And we’re wasting our money “protecting” ourselves from dangers that barely blip on the radar in the natural world.
Believe you me…I’m more worried about an antibiotic-resistant strain of influenza than I am about anthrax…and you should be, too…
Update (12/2/05): Case in Point. Here’s an article about a new strain of bacteria that is proving difficult to fend off… Be afraid…be very afraid…
Um I learned about antibiotic resistance in jr high, maybe not this much detail but still we were told about it.
So my point – I fully agree it is a legitimate concern but what can we(as in I the average josephine/joe) do about it? Direct my concern into some productive means.
The “average joe?” Probably not much… I mean, writing your local congress-person and/or organizing support for the position will only do so much. We’ve already learned from intelligent design discussions that the government isn’t interested in many things the scientific community has to say, unless it can lead to increased military power or money. So yeah, I’m certainly open to discussions… I guess you can try to not get sick? Keep your immune system strong so it can fight off infections without needing antibiotics? Who knows…probably no real answer, unfortunately…
wouldn’t a transposon only be able to move an existing gene. I think the real threat is from a transposon leaving an artifact in just the wrong place that creates a new, antibiotic resistant gene. Or some other mutation. Then everyone uses antibiotics (and btw, they use like, 80% fewer antibiotics on the west coast than we do here in the midwest, to try and combat all of this) and you kill off the bacteria that don’t have that gene, leaving only those that do to reproduce…
So Kate,
for starters.. don’t use anything that says it’ll kill 99.9% of germs, because that will leave us the other .1% to reproduce and pretty soon our hand sanitizers won’t be able to kill anything, let alone our severely outgunned immune system.
The transposons in bacteria use a variety of mechanisms, from replicative (more like normal) ones to non-replicatives (jumping) ones. Bacteria can have “sexual” reproduction in a sense as well, which promotes their genetic diversity…which also allows for transposons to “jump genomes”…
wouldn’t you still need there to be that resistant gene for the bacteria to move from the one genome to the next?
I don’t think I really understand the question, but remember that transposons can either replicate or jump (they can’t necessarily do both, but there are both kinds). Dr. Dorsett explained it to us, but used a drawing of E. coli during its replication process (which is when the jumping is more likely to occur). He drew it in such a way that it could jump and replicate at the same time during replication. And if it jumps from genome to plasmid (because bacteria have both…), then the plasmid can be “sexually” incorporated into another bacteria without removing resistance from the original host.
Is that helping?
…and…just to make sure you see this, too (even though I added it to the main post):
http://abcnews.go.com/Health/wireStory?id=1364208
I seeeeeeeeee. yeah, the part about the plasmid makes it make sense to me.
obviously, this is way over my head. but glad you and Nathan seem to understand. Since this stuff will effect my grandkids more than me – you guys better be working on the solution!!