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.'"

scifi tag?

[haluness]

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

Mitochondria

[flyingfsck]

Hmm, weren't mitochondria, that occur in all our cells, originally symbiotic bacteria?

Dawkins

[Colin Smith]

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.

 

humility, what's that?

[Once&FutureRocketman]

But of course we understand genetics and the dynamics of genome development well enough that it's perfectly reasonable for us to manipulate the genes of our primary food crops and release them into the wild. No problem there.

Re:scifi tag?

[linguizic]

Not only that, but it seems that geneticists are now thinking that mtDNA directs the expression of the genes encoded in the nuclear DNA. So things are MUCH more complex than we once thought (no surprise there).

Re:humility, what's that?

[cnettel]

Yep, no problem. After all, this shows that the species barrier (which is one of the main criticisms against GM crops) is thinner than believed. We get an interesting variety through modern methods. The problem of a not completely described monoculture is still a significant one, but the foodcrop varieties already in use are already such monocultures. Preserving local varieties in some form is essential, but those varieties are on the other hand not good enough to feed us all.

Re:There are retroviral genomes in ours genome

[Spy der Mann]

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.

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[account_deleted]

Comment removed based on user account deletion

Benefits for the host?

[Spy der Mann]

FTA:

Werren and Clark are now looking further into the huge insert found in the fruitfly, and whether it is providing a benefit. "The chance that a chunk of DNA of this magnitude is totally neutral, I think, is pretty small, so the implication is that it has imparted of some selective advantage to the host," says Werren. "The question is, are these foreign genes providing new functions for the host? This is something we need to figure out."

I wonder if this has already happened to humans through generations. In fact, I wonder if this is a standard working component of evolution, where bacteria are a catalyst. It seems that nature always gives us nice surprises to keep us in awe and realizing we don't know anything about biology.

(As a side note, I was suddenly reminded of the Metroid Fusion game, where Samus absorbs the X cores' DNA and incorporates them into her system)

Mebbe it's just me but

[hyc]

I think it would be interesting to take a person's stem cell and try to remove all the "junk DNA" from the nucleus, then grow the cell thru a few generations (perhaps even to a full clone) and see how different it is from the original person. Very likely a lot of what we think is junk DNA isn't useless after all. Probably the reason we have 46 chromosomes in the first place is that we've been accumulating genetic material from other microbes over the span of millions of years...

Oh yeah.

[Erris]

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

Newer concerns are better written and documented here by a Monsanto whistle blower [seedsofdeception.com]. We already know that the industry was sloppy because unapproved GM crops have contaminated the US rice supply [washingtonpost.com]. 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.

Re:There are retroviral genomes in ours genome

[ColdWetDog]

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 [rice.edu]

All your base (pairs) belong to us!

Re:Dawkins

[shaitand]

'Jesus said, "Blessed is the lion which becomes man when consumed by man; and cursed is the man whom the lion consumes, and the lion becomes man."

--Gospel of Thomas'

Since Thomas didn't write the Gospel of Thomas (and the same is true of all the books in the new testament) what you are really saying is that someone wrote that someone said that someone else said "Blessed is the lion which becomes man when consumed by man; and cursed is the man whom the lion consumes, and the lion becomes man." And lets just ignore the fact that the one who wrote that knew neither Thomas nor Jesus and lived long after the death of anyone who did.