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One Species' Genome Discovered Inside Another's

slyyy writes "The Universtiy of Rochester has discovered the complete genome of a bacterial parasite inside the genome of the host species. This opens the possibility of exchanging DNA between unrelated species and changing our understanding of the evolutionary process. From the article: 'Before this study, geneticists knew of examples where genes from a parasite had crossed into the host, but such an event was considered a rare anomaly except in very simple organisms. Bacterial DNA is very conspicuous in its structure, so if scientists sequencing a nematode genome, for example, come across bacterial DNA, they would likely discard it, reasonably assuming that it was merely contamination--perhaps a bit of bacteria in the gut of the animal, or on its skin. But those genes may not be contamination. They may very well be in the host's own genome. This is exactly what happened with the original sequencing of the genome of the anannassae fruitfly--the huge Wolbachia insert was discarded from the final assembly, despite the fact that it is part of the fly's genome.'"

17 of 224 comments (clear)

  1. There are retroviral genomes in ours genome by Anonymous Coward · · Score: 4, Interesting

    There are multiple retroviral genomes in our own genome. So I am not too surprised.

    http://genomebiology.com/2001/2/6/reviews/1017

    1. Re:There are retroviral genomes in ours genome by Spy+der+Mann · · Score: 4, Insightful

      Yes, but it's part of a virus' nature to insert its DNA into the host. THat's how they work. This is a BACTERIAL genome. Bacteria don't just mix themselves into the hosts.

    2. Re:There are retroviral genomes in ours genome by eli+pabst · · Score: 5, Interesting

      Wolbachia are kind of funky though. They can live inside of host cells (as an intracellular symbiont) which is a bit uncommon for most bacteria. They do weird things like infect female gametes (eggs) and kill male offspring, that way only infect females will be produced. Still doesn't take away from the fact that you have a bacterial genome integrated into it's host. But they're definitely not a run of the mill bacteria.

    3. Re:There are retroviral genomes in ours genome by eiapoce · · Score: 5, Funny

      the Bacteria had done precisely that. Do you think that the retrovirus now could sue for this outstanding patent violation?

      Enrico
    4. Re:There are retroviral genomes in ours genome by ColdWetDog · · Score: 4, Insightful
      Wolbachia are kind of funky though. They can live inside of host cells (as an intracellular symbiont) which is a bit uncommon for most bacteria.

      Sounds a bit like the story of the mitochondria

      All your base (pairs) belong to us!

      --
      Faster! Faster! Faster would be better!
  2. scifi tag? by haluness · · Score: 5, Insightful

    What's with the scifi tag? This is real stuff, not fiction. And not entirely surprising sicne mitochondria in humans are (hypothesized?) ancient bacteria that have been incorporated into the human genome

    1. Re:scifi tag? by TheMeuge · · Score: 5, Informative

      The mitochondria have not been incorporated into the human genome. Mitochondria contains its own circular DNA structure, which exists and replicates independently of the genomic DNA. There must have been some gene loss/exchange, however, because many proteins necessary for mitochondrial structure and function are found solely in the genomic DNA.

    2. Re:scifi tag? by eli+pabst · · Score: 4, Informative

      There are mitochondria in both sperm and egg. Offspring generally inherit only the mothers mitochondria, though their have been a few reported cases paternal mitochondria inheritance. I believe the theory is that while they are present in both male and female gametes, the males mitochondria are degraded almost immediately after fertilization.

  3. Round up ready weeds and other horrors. by Erris · · Score: 5, Interesting

    This discovery is unsetling and I hope that it's an error. There's already evidence that pesticide resistance from GM crops has turned up in weeds. Gene swapping in the wild might happen more often than we would like. Some of the unpleasant possibilities include food you can't eat, cotton you can't wear and weeds you can't get rid of.

    --
    DMCA, Hollings, Palladium. What might have sounded like paranoia is now common sense.
  4. Wow by pete-classic · · Score: 4, Funny

    I thought I was into some kinky shit, but I never tried to stick my genome into someone.

    -Peter

  5. Dawkins by Colin+Smith · · Score: 4, Insightful

    Not so surprising if you've read Dawkins (For the non geneticists among us).

    You see, according to him, we are machines whose purpose is to allow genes to replicate. The fact that other genes co-opt this mechanism isn't entirely surprising if you look at it from that perspective.

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    Deleted
  6. mitochondria, chloroplasts, viral DNA by brit74 · · Score: 4, Informative

    I haven't heard of a whole genome being inside another species. Although, the mitochondria (which are small energy producing factories inside most life - including mammals) have their own DNA which is separate from our nuclear DNA. Its DNA sequence resembles the sequence of single-celled organisms, which hints that there was a fusion of two different organisms hundreds of millions of years ago. Additionally, plants have chloroplasts (which do photosynthesis), and these are similar - they appear to have been cyanobacteria (independent organisms) that fused with another organism and became organelles within those cells. There are also bits of viral DNA in our own genome - it apparently fused into our DNA long ago. (In fact, you can trace evolutionary relationships by comparing the sequence and positions of these viral bits of DNA across species. Unsurprisingly, humans and apes share a remarkable number of matching viral DNA chunks.)

  7. Re:i don't care by Anonymous Coward · · Score: 4, Funny

    Agreed. He is a rather attractive fellow in a greasy, bald kind of way.

  8. phoenix by wizardforce · · Score: 4, Informative

    roughly 8% of our own species' genome consists of bacterial and viral genetic material. some of the segments are nearly complete with at least one case of a virus being resurected called Phoenix. it seems to be a fairly common process, viruses can lose critical genes while trying to replicate in cells which can leave them unable to reproduce as usual, the genome becomes integrated into our own. there are also cases [herpes for example] which can integrate their genome with ours in certyain cells and effectively become dormant, they start the cycle again when and if certain conditions are met. http://www.nytimes.com/2006/11/07/science/07virus. html?ei=5088&en=492dd1d370217836&ex=1320555600&adx nnl=1&partner=rssnyt&emc=rss&adxnnlx=1163032655-5n RqAOkgWGeKvh/qQcSYCg

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    Sigs are too short to say anything truly profound so read the above post instead.
  9. Comment removed by account_deleted · · Score: 4, Insightful

    Comment removed based on user account deletion

  10. Oh yeah. by Erris · · Score: 4, Insightful

    Weeds have already been given pesticide resistance through regular polenation and natural selection. This is bad enough because it defeats the purpose and there are plenty of studies that GM crops are harmful to wildlife, including mysteriously disappearing honey bees.

    Newer concerns are better written and documented here by a Monsanto whistle blower. We already know that the industry was sloppy because unapproved GM crops have contaminated the US rice supply. It may be that the people who worried about GM crops were right and evidence of genes crossing species is just one of the many things they feared. Genetic sequencing is new and bound to bring big surprises.

    It's good practice to keep an open mind but be careful until you know things are safe. A couple of historical examples show how caution works and what industry does when it's not careful. People who hear about the use of lead and arsenic in paint and wallpaper often wonder how people could be so stupid as to have that kind of thing in their homes. The answer is that printers and painters overstepped their knowledge and embraced new toys that made them money. At the opposite end of the of caution is Rontgen, the discover of Xrays. He was very careful to shield all of his sources with lead bricks because he did not know what his newly created rays would do to him. Unlike many of his contemporaries, he did not die of cancer. People continued to expose themselves needlessly for half a century before sane practices were finally codified.

    --
    DMCA, Hollings, Palladium. What might have sounded like paranoia is now common sense.
  11. Re:Parasites and host behavior by smellsofbikes · · Score: 4, Interesting

    I just read a superb book called "Survival Of The Sickest" that went on at *length* about parasite control of parasitized animals, from wasps that sting spiders and implant eggs, that during their development cause the spiders to weave cocoons for the hatching wasps, through the effects of toxoplasmosis on altering how mice behave so they get eaten by the toxoplasmosis host, to other things I'd never even considered. Guinea worm is this horrible disease where a worm bores through your skin with acid. It hurts, a lot, so people go find rivers and pools because the water makes it hurt less -- and the guinea worm dumps eggs as soon as it's in water, to get the next person who drinks from that water. Rabies infects brains, making animals aggressive, and also concentrates in saliva, so the aggressive animals are more likely to bite and transfer the disease. The book even went over some guidelines for predicting how lethal a disease would be, based on its mode of transmission: typically, we've thought that diseases get less lethal over time because that increases their ability to spread, but the book says it depends on the transmission path. Malaria wants -- inasmuch as a disease can want anything -- people to be very ill indeed, so that they spend lots of time not moving, giving mosquitoes a better chance of finding the people, while colds do want people to be as mildly sick as possible so they can maximize their distribution. A particularly neat case is cholera, which can be spread by human-human contact, or more usually by contamination of drinking water. In the latter case, the sicker the person, the better, because more bacteria will be voided by the person through diarrhea, while in the former case, milder infections spread more because there's longer-term contact with heath care personnel, meaning more chances to spread. Watching cholera epidemics in South America, that's exactly what they observed: in countries that were poor, where there wasn't really any official health care, the disease became progressively more lethal over time, while in countries where infected people got immediate health care, the disease got less lethal over time. It's not a bad read, although the doctor who wrote it, Sharon Morel (I believe) should've just written it, instead of hiring a ghost writer who turned it into a succession of USAToday-feeling articles.

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