REPOST: Morons in Microbiology


This is a repost from the old ERV. A retrotransposed ERV :P I dont trust them staying up at Blogger, and the SEED overlords are letting me have 4 reposts a week, so Im gonna take advantage of that!

I am going to try to add more comments to these posts for the old readers– Think of these as ‘directors cut’ posts ;)

So like, you know when people go all Monty-Burns-as-Howard-Hughes and start seeing germs everywhere?

I dont have that. But I kind of have that. Somehow, I work viruses into every aspect of my life… Including poop.

So I gotta say to PalMD:

Its not the bacteria! Its bacteria + PHAGE!!!! PHAAAAAAAAGE!! THEYRE EVERYWHERE!!!!

In a recent Denialism post, Pal talks about poopages. Ya he mentions a virus, but then he lists all these bacteria like bacteria are the Big Dogs. Noooooooooo!!! The bacteria only cause diarrhea cause of genes encoded by phages!

Didnt he read my post on morons???? hehehehehe!



No, not the Usual Morons in Microbiology– These morons have been around for billions of years!!

A moron (in bacteriophage biology) is a DNA element inserted between a pair of genes in one phage genome when the genes of this same pair are adjacent in a related phage genome.

hmmm.. yaaa… Not so helpful, ASM. Luckily, Bossmans lecture on morons in class this week was much clearer.

‘Morons’ are genes that bacteriophages carry around which are unnecessary for the virus, but helpful for the host bacteria.

This doesnt make sense at first, because when we think of viruses (especially bacteriophages) we think of infection, making lots of baby viruses, and BOOM!!– cell explodes and all the viruses are released. Why would it care if the bacteria is comfy as its exploding?

Well, thats not really what happens with phages. They infect a cell, insert themselves into the bacterias genome, and chill. They just sorta hang out until some stressor tells the virus its time to jump ship. Think about it– who is more fit, a virus that blows up its host and produces a thousand progeny who might/might not find another host cell, or a virus that sits silently in a genome, getting passed down through the generations laterally for a million years? The latter! But while hiding in someone elses cell is a good idea, silent phages have the same problem as plasmids– How do you convince a bacteria to keep you around when you are genetic dead weight?

MORONS!

LOL!!!

Morons help the bacteria survive by being novel genes that make the bacteria more competitive with its peers in an old niche, or giving the bacteria the ability to exploit a new niche. Morons are kind of hard for us to appreciate… Like the MORON that encodes Type III secretion effectors that make you poop when youre colonized by Salmonella or the MORON toxins that make you poop when youre infected with Cholera or the MORON toxins that make you poop when you eat spinach sprinkled with E. Coli… but theyre actually a really cool evolutionary story, demonstrating the co-evolution of bacteria and their phages over time! Bacteria even have ‘endogenous phages’ like we have endogenous retroviruses!

I was rather pouty about getting my PhD in microbiology because of all of the associated ‘bacteria based’ classes I would have to take (Ive never taken an intro micro class– cocci-wha?), but this stuff is friggen fun!

NEW TO THIS POST:
Go to friggen Evilutionary Biologist and search his blag for ‘PHAGE’!!!

Comments

  1. #1 Don Smith, FCD
    June 5, 2008

    Yeah, so the bacteria got all these cool toxins from phages. So where did the phages get the toxins? Mightn’t that have been a bacterium? Perhaps an Archaean? (How come my spell checker doesn’t know how to spell phages? Is there a latinate plural or something?)

  2. #2 efrique
    June 5, 2008

    Yeah, that one blew me away the first time around. It’s freaking cool.

  3. #3 clinteas
    June 5, 2008

    Rudely OT,but I couldnt help it:

    The argument for intelligent design from magic shell….

    http://www.youtube.com/watch?v=8pR5PJBln7E

    Enjoy !

  4. #4 The Backpacker
    June 5, 2008

    If this is a really dumb question sorry but I am just a bio wana-be still. What is the advantage to an E. Coli or Cholera strain that makes me want to die as opposed to a strain that just hangs out not causing problems?

  5. #5 ERV
    June 5, 2008

    @4– Because you poop and then bacteria can spread to knew hosts, fecal to oral :) Poopie is the key** Its like how inluenza makes you feel like crap, but you cough/sneeze, which spreads the virus to new hosts!

    ** We laugh, but people die from this, if they dont have access to adequate medical treatment…

  6. #6 The Backpacker
    June 5, 2008

    I did not mean to make light of other people’s suffering just mine. I understand, fogot that not everyone has indoor plumbing.

  7. #7 ERV
    June 5, 2008

    Oh I didnt think you were making light of it– I just didnt want people to think I was making light of it :P

  8. #8 Felstatsu
    June 5, 2008

    The advantage to various illnesses making you do certain things is that those actions tend to either be how it spreads directly or something related to how it spreads. If it got along peacefully in you it’d only last as long as it took for your body to recognize foreign material and destroy it, even though it wasn’t doing anything. Instead, by making you ill, anything it can use to get outside of your body so that it can potentially enter other hosts becomes desirable to induce any way it can.

  9. #9 Felstatsu
    June 5, 2008

    Bleh, took too long to type while at work, got beaten to answering >.>

    Though I did think about another reason to spread instead of chill out peacefully. It’s got to spread to get more resources, and if it sticks around in the same place just getting the same nourishment, eventually some other meaner bug is going to come along and take over and the bacteria/virii dies out since it didn’t spread anywhere else. There’s simply too much pressure for survival for a disease that doesn’t spread to have a chance.

  10. #10 clear as mud
    June 5, 2008

    Oh poo, I was gonna bring up the negative-reinforcement side of it (longlasting poison, shorliving antidote) but I see you talked about that a while back.

    The bottom line is, as with all evolutionary stories, anything that works works. Positive incentive (“Keep me and I’ll make you AWESOME!”), negative (“Toss me out and you DIE!”), and neutral (integrating onto the chromosome, like lambda, or becoming a self-sustaining and self-partitioning plasmid, like P1). Sometimes, it’s all three. Whatever works.

  11. #11 Sili
    June 5, 2008

    There’s a PHAGE-OT joke in here somewhere, but it’s too late for me to find it.

    I PHAGE-L.

  12. #12 PalMD
    June 5, 2008

    Hey, I only have so many electrons alloted to me daily. I couldn’t get to all the fun bugs, or the lovely Shiga toxin. Plasmids are cool…unless you’re pooping.

  13. #13 Gege
    September 2, 2011

    Plasmids are awesome (I work on the B. anthracis ones). Phages are kind of okay, I suppose… :)

    I had never encountered the “moron” term for intervening genes, I wonder who came up with that. Speaking of that type of terminology, I quite like the term “ORFan” for predicted genes that don’t have any known homologs.

  14. #14 eddie
    September 4, 2011

    Is it related to the term ‘useful idiot’? :-)

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