Evolution in action -Cross Species genetics right here on Ea

[blacknblue]

My daughter sent me this link.

http://www.rochester.edu/news/show.php?id=2963

<quote>

One Species' Genome Discovered Inside Another's

Bacterial to Animal Gene Transfers Now Shown to be Widespread, with Implications for Evolution and Control of Diseases and Pests

Scientists at the University of Rochester and the J. Craig Venter Institute have discovered a copy of the genome of a bacterial parasite residing inside the genome of its host species.

The research, reported in today's Science, also shows that lateral gene transfer—the movement of genes between unrelated species—may happen much more frequently between bacteria and multicellular organisms than scientists previously believed, posing dramatic implications for evolution.

Such large-scale heritable gene transfers may allow species to acquire new genes and functions extremely quickly, says Jack Werren, a principal investigator of the study. If such genes provide new abilities in species that cause or transmit disease, they could provide new targets for fighting these diseases.

The results also have serious repercussions for genome-sequencing projects. Bacterial DNA is routinely discarded when scientists are assembling invertebrate genomes, yet these genes may very well be part of the organism's genome, and might even be responsible for functioning traits.

"This study establishes the widespread occurrence and high frequency of a process that we would have dismissed as science fiction until just a few years ago," says W. Ford Doolittle, Canada Research Chair in Comparative Microbial Genomics at Dalhousie University, who is not connected to the study. "This is stunning evidence for increased frequency of gene transfer."

"It didn't seem possible at first," says Werren, professor of biology at the University of Rochester and a world-leading authority on the parasite, called wolbachia. "This parasite has implanted itself inside the cells of 70 percent of the world's invertebrates, coevolving with them. And now, we've found at least one species where the parasite's entire or nearly entire genome has been absorbed and integrated into the host's. The host's genes actually hold the coding information for a completely separate species....."

(continued in rest of article)

</quote>

How mind blowing is that?

NOTE: Bacteria are plants.

[Distracted]

Coolness.

Some biologists theorize that mitochondria used to be parasitic bacteria that over millenia of evolution have now become integral parts of all eukaryotic cells. I guess they might be right.

[Distracted]

Heh. I just read the article and it actually mentions mitochondria. I wonder if this parasite could be genetically modified to act as a vector for gene therapy in humans if it's so good at inserting its DNA into a host genome. Research is ongoing to do that with viruses, but parasites are more complex and therefore easier to kill than viruses. For that reason, they'd be safer. When you want them to stop doing their genome altering thing, all you have to do is kill them with antibiotics. Antivirals are harder to make and generally don't work as well, so there's always the risk that a virus vector might multiply out of control. A parasite would be less worrisome.

This would be a neat premise for an SF novel, y'know? Intrauterine injections of genetically engineered parasites would correct hundreds of hereditary disorders, and the treatment would produce permanent changes in the genome which carry over to the next generation...BUT... what other irreversible changes would occur? Would humans still be human in ten generations? *cue ominous music*

[Elessar]

Heh. I just read the article and it actually mentions mitochondria. I wonder if this parasite could be genetically modified to act as a vector for gene therapy in humans if it's so good at inserting its DNA into a host genome. Research is ongoing to do that with viruses, but parasites are more complex and therefore easier to kill than viruses. For that reason, they'd be safer. When you want them to stop doing their genome altering thing, all you have to do is kill them with antibiotics. Antivirals are harder to make and generally don't work as well, so there's always the risk that a virus vector might multiply out of control. A parasite would be less worrisome.

This would be a neat premise for an SF novel, y'know? Intrauterine injections of genetically engineered parasites would correct hundreds of hereditary disorders, and the treatment would produce permanent changes in the genome which carry over to the next generation...BUT... what other irreversible changes would occur? Would humans still be human in ten generations? *cue ominous music*

Haha, that's awesome. I didn't know about the mitochondria theory, but that's friggin awesome. Wouldn't that have represented a HUGE step in the development of the primordial cell to what we see as a cell today? Are they able to look at cellular fossils from long enough ago to see eukaryotes that didn't have mitochondria?

Also wondering, D, about this idea you had (which is awesome), for conducting gene therapy with these... When it comes to correcting heriditary disorders with gene therapy, how many different disorders do they already know which genes to change and in what way, yet just don't have a way of introducing the new DNA seemlessly? Or rather, is the problem still actually FINDING the genetic segments that control most disorders?

I ask in reference to my color deficiency. It's hereditary... and I would like to know if they know at all which genetic markers control/activate color vision, and therefore if they know what parts of DNA to mess with, and just don't have a way to do it yet? Or do they just have no clue what part of our DNA controls color vision?

[blacknblue]

The science fiction possibilities are limitless.

Scenario:

A Human and a Vulcan want to have a child. Instead of trying to mix Human egg and Vulcan sperm, the Human mother consents to having a clone of herself developed in-vitro and then implanted in her womb. Once the embryo has implanted and begun normal development, an artifically cultured Vulcan parasite is used to insert the Vulcan father's genome into the baby.

Or maybe that wouldn't work, since the developed clone would already have a full set of chromosomes?

Try this instead. Extract a diploid cell from each parent prior to meiosis, when they still have a full set of genetic material. Insert Vulcan material into the Human cell, and Human material into the Vulcan cell. Then let the cells divide. It might take a few thousand tries, but eventually you would end up with a pair of haploid cells with a 50-50 percentage of Human-Vulcan genetic material on each side.

Oh, the possibilities...

I mean, shit. Bacteria are PLANTS people. If a freakin' plant can adapt itself well enough to infuse its genetic material to bond with an animal, why can't one animal adapt itself to bond with another animal. Even one with a slightly differing body chemistry. Remember that Earth invertebrates have copper based blood, and they have no problem feeding upon us, and vice versa. Also, we have no problem passing diseases back and forth. And many copper based Earth parasites take up residence inside iron based vertebrates quite comfortably.

[justTripn]

Well you probably heard about the monkey with glowing green jelly fish genes? Really. They wanted the monkey to be floresent for some reason. It would have made their scientific studies easier somehow. The monkey that was born had the jelly fish genes but wasn't floresent. However some of the aborted fetuses WERE floresent.

I just googled it. "Efforts to make a fluorescent green monkey are not quite a glowing success . . ." reported in 2001.

[CoffeeCat]

oooo - green monkey. The fanfic possibilities....

[krn]

Actually, BnB, bacteria are not plants. They're not animals either. bacteria are bacteria. In order to be a 'plant' some of the organisms cells must have chloroplasts (the bits that makes plants green, they convert sunlight into energy).

Chloroplasts are similar to mitochondria in that they may have been independent bacteria at one time that have become organelles.

In the lab I work for, we use a bacteria called 'agrobacterium' to genetically transform citrus plants. The wild type agrobacteria "injects" a chunk of DNA into a plant host (often trees, where they are wounded along their base). This chunk of DNA acts like a virus, and makes the host plant make food and components for the agrobacteria. It results in galls forming on the infected plant. We use a engineered version that will not form galls, but still injects the chunk of DNA. We modify said 'chunk' (the fancy term is 'plasmid') with our gene(s) of choice and let the agrobacteria do the work.

Unfortunatly, the efficiency is under 10%. Depending on what variety of citrus we're working with, it can be much, much less. To date, we don't have any citrus out there commercially. We've got hundreds in the greenhouse, and we're in the process of testing weither the new genes are working as expected.

Considering all we know about life - it's amazing how much we're *still* learning.

[Linda]

All this is very exciting. Hey, read Michael Crichton's novel "Next" for more gene fun. And I like that in this novel, they did not kill the parrot ( a genetically enhanced parrot who helped a child with his math homework). Unlike the latest Harry Potter book where

SPOILER!!!:

Harry's owl was the first casualty.

[blacknblue]

Actually, BnB, bacteria are not plants. They're not animals either. bacteria are bacteria. In order to be a 'plant' some of the organisms cells must have chloroplasts (the bits that makes plants green, they convert sunlight into energy).

Chloroplasts are similar to mitochondria in that they may have been independent bacteria at one time that have become organelles.

Fascinating. Either my knowledge base is obsolete, or my senile old brain is deteriorating at a rate even more rapid than I had realized. I would have sworn that I was taught back in the day that bacteria were classed as plants. But then, I predate some of the fancier types of classifications in the system. In my day there were plants, animals, and ahem... other.

Later, after checking:

Now I think I remember. It has been more than a few years since I studied this.

<quote>
Autotrophic bacteria (also known as autotrophs) obtain the carbon it requires from carbon-dioxide. Some autotrophs directly use sun-light in order to produce sugar from carbon-dioxide whereas other depend on various chemical reactions. Heterotrophic bacteria obtain carob and/or sugar from the environment they are in (for example, the living cells or organism they are in)...
</quote>

I was thinking of autotrophic bacteria. I haven't touched this since college to any practical degree. I dropped using my biological training in favor of civil engineering almost the moment I took the diploma in hand, and never looked back except for a layman's casual interest.

I was also thinking strictly in terms of the original three kingdoms- plant, animal and decomposer like molds, etc. It was very late last night and I was low on coffee. Forgive me please.

[evcake]

Have they discovered farandolae in the mitichondria yet?

[Elessar]

Or medichloreans?

[evcake]

[Distracted]

Also wondering, D, about this idea you had (which is awesome), for conducting gene therapy with these... When it comes to correcting heriditary disorders with gene therapy, how many different disorders do they already know which genes to change and in what way, yet just don't have a way of introducing the new DNA seemlessly? Or rather, is the problem still actually FINDING the genetic segments that control most disorders?

The human genome's been completely sequenced. The main problem is that we don't know what a lot of it does. It'll probably take decades of research to figure out what all the genes code for. So far, there's only a limited number of hereditary diseases and cancers caused by single gene mutations that we can definitely identify that are potential candidates for gene therapy. There are several diseases that could be treated that way within the next few years. It's already been done with SCID and melanoma, and has been attempted but not successful yet (probably won't be long) with sickle cell anemia, thalassemia, cystic fibrosis, and some forms of muscular dystrophy. Cool, huh?