Virus Sexy Time

No, I dont mean viruses you get from sexy time. I mean virus sexy time. Viruses having sex, ie, shuffling round their genetic material.

They do it a lot.

HIV-1 sexy time
Ive written about before– because HIV-1 is diploid, two copies of the genome are packaged into one virus. There is lots of ‘hopping’ during reverse transcription, so sometimes things dont ‘hop’ perfectly, and the resulting virus is different from both of its ‘parents’. Thats how HIV-1 gets a shitload of its diversity (NOT just error-prone reverse transcription).
So sometimes HIV-1 sexy time leads to subtle polymorphisms:

Sometimes it leads to a gene duplication (or deletion):

And sometimes, if two different kinds of HIV-1 have infected the same cell, a virus can contain two different genomes. When sexy time comes, the resulting baby-virus can be a totally new mixture of its parents:

We call these guys circulating recombinant forms, and they make vaccine design a bitch.

But retroviruses arent the only ones that can has sexy time.

Segmented viruses love genetic reassortment too. Hell, thats how we got ‘SWINE FLU OMFG 2009′– pigs can be infected by both ‘avian’ and ‘human’ influenza viruses (we normally cant be infected by the bird kind, has to do with sugar, not blagging about that).

Because influenzas genome is 8 pieces of RNA, if one piggie cell is dually infected with a bird virus and a human virus, the baby virus can get say, 3 segments from the birdy virus, and 5 segments from the human virus, and be an avian/human chimera. Well in ‘SWINE FLU OMFG 2009′, a >20 year-old avian/pig virus recombined with a >10 year-old human/pig virus to make a brand new avian/human/pig virus (2/1/5 segments, respectively).

Basically this:

The avian/human/pig virus didnt come from one poor pig infected with all three. An avian/human/pig influenza is just a natural side effect of influenza sex.

Viruses have sex. Its a major source of genetic diversity for a lot of viruses, and a major headache for us.

Comments

  1. #1 Prometheus
    May 13, 2009

    So Manbirdpig Flu is an appropriate epithet?

    Still like “The Aporkalypse” better.

  2. #2 JD
    May 13, 2009

    Nothing worse than a gene encapsulated in protein to ruin one’s OMFG weekend.

  3. #3 Mind Over Splatter
    May 13, 2009

    “So there you go. You’re the retarded offspring of five monkeys having butt-sex with a fish-squirrel. Congratulations!”

    Geez, I hear this coming from Creationists all of the time. Don’t they ever come up with anything new ?

  4. #4 Marc Buhler
    May 13, 2009

    Hi Abbie,

    No doubt you will be hearing more about how the
    *birth* of viruses just got a big step closer:

    http://www.nytimes.com/2009/05/14/science/14rna.html?hp

    If a reasonable model of abiogenesis is within reach,
    whatever are the evolution-denialists going to do?

  5. #5 Lee
    May 13, 2009

    You should write a textbook.

    In your spare time, of course.

    I’m serious, though. Your ability to explain complex facts and ideas, in ways that make them SEEM trivially simple while still capturing the complexity – and is also fun to read – is truly a gift.

    A senior high-school or basic college biology text, or a college introduction to virology for non-majors, written in your style so that the complex issues become transparent to students who are often not properly prepared, would be wonderful – I wish it had existed when I was teaching Intro to Bio at community college.

    Maybe you can include it as a chapter in your thesis. Grin.

  6. #6 Optimus Primate
    May 13, 2009

    Chicka-bowwow chicka-bowwow chicka-bowwow.

    Yuck!

  7. #7 Raimund
    May 14, 2009

    Awesome! Thank you so much for clearing that up for me! I was really quite confused about how a virus could recombine, but you made it completely clear. And yeah, I can see how that sort of genetic recombination would make for an amazingly complicated problem for making vaccines. My next question pertains to what happens when a recombined or mutated virus reinfects a person who’s already had the virus before it mutates, say like with the 1918 Spanish flu pandemic. So say you got the virus in 1917, then the more deadly version in 1918. Since most of the people who died from it didn’t die of secondary infections, like they do with most flu deaths, but rather from their own immune response, would having had the pre-mutated virus lessen the severity of the immune response or does that have no effect at all?

    Anyway, I’m totally stoked that you answered my question. Thanks! You’re totally l33t!

  8. #8 clinteas
    May 14, 2009

    Segmented viruses love genetic reassortment too. Hell, thats how we got ‘SWINE FLU OMFG 2009

    Or did we?

    http://www.thesundaily.com/article.cfm?id=33468

  9. #9 Rev. BigDumbChimp
    May 14, 2009

    Hamthrax

    I’m waiting for the manbearpig Flu.

    Clinteas, how long until that is conspiracy theory #1 in the SCIENTIS R TEH EBIL crowd?

  10. #10 clinteas
    May 14, 2009

    Chimpy,

    its being treated as a reasonable theory over here,Im yet to see anyone showing its not true……
    Of course I love my conspiracy theories lol ! But this one looks feasible,at least,I wonder what Abbie has to say about it.

  11. #11 Rev. BigDumbChimp
    May 14, 2009

    its being treated as a reasonable theory over here,Im yet to see anyone showing its not true……
    Of course I love my conspiracy theories lol ! But this one looks feasible,at least,I wonder what Abbie has to say about it.

    Really?

    Interesting. Think of the boost that will give the CT nuts if it actually is true.

    “See look right there we told you this was created by the Government! That also means we are right about the CIA creating AIDS to keep the black man down!!!!!!!1111one11!”

  12. #12 ERV
    May 14, 2009

    #8– Actually, a Big Wig influenza researcher is on my committee. She is friends with Adrian Gibbs, and is helping him investigate where this particular strain came from. However, we are fairly certain it didnt come from any vax, because of OMFG SWINE FLU 2009 behavior.

    For example, we initially thought Parvovirus came from a vaccine because it showed up all over the world at the same time. OMFG SWINE FLU 2009 did not.

    As far as a lab ‘leaking’– we know what strains OMFG SWINE FLU 2009 is from– one piggie virus isolated in Indiana and one isolated in Europe. We know who has these viruses and who works with them– Does any scenareo match up? Im guessing no, at this point.

  13. #13 Sili
    May 14, 2009

    OP, don’t you mean “Oink chica oink-oink?” It’s not manDOGbird flu after all.

    So many jokes, so little talent – I can’t even come up with something using “Four legs good. Two legs bad.”

  14. #14 eddie
    May 14, 2009

    If flu virologistas had been working on the particular 2/1/5 recombination we are experiencing, we’d have a head start on finding a vaccine, no? There’s still the question of why Mexico. As for accidentally finding novel recombinations, isn’t that what the bacon industry does?

  15. #15 Hu
    May 15, 2009

    “Sorry, not tonight, honey. I have a capsidache.”

  16. #16 MsNova
    May 19, 2009

    Hi, I’m curious about the amount of mutations hiv goes through. I’ve heard that’s the problem with creating a vaccine…even in one patient from one day to the next no two hiv’s are the same.

    Also, since the hiv tests are just tests for antibodies, how could you know, even if managing to overcome the problem of mutations, that a vaccine was successful? What is the difference between antibodies created in response to the virus and antibody immunity created by a vaccine?