Forgive me for getting excited about new technology in my field. And no, I do not have stock in 454. Geez, I'm a grad student, I barely have a penny to my name;P I brought it up because it's useful in this field, pertains directly to the topic, and this is a place where all us nerds can get excited about this sort of thing.
Please tell me with a straight face that you think you would have thought up doing a thousand simultaneous PCR reactions in an oil emulsion on beads then sequencing off the beads using fluorescence on an array...and I'll eat my hat. heh. It's smrt.
Also, I'll give you, hands down, that you're right that the sequences would be shorter...let's say 5 times shorter. That'd be enough bases for most studies. Honestly, how often do you think 100 bases are gonna repeat letter for letter in the genome. Heck, the longest primer I ever had to order... for normal uses... was 45. And anyway, the sort of stuff you're sequencing using this method is not the same as what you'd use a capillary system for. We're not talking getting perfect sequences, we're talking getting enough data for stats to give us something new/interesting. It's not the be all and end all, but it's a step toward it. It's a tool for something we had poor tools for in the past, so it's a good tool.
Man, I just wanna be able to sequence all the viruses I make in one go. Anything that gets me closer to that is what I call cool. 454 might not be what I need, but it sure as heck is a step toward it.
We recently had a speaker here to introduced us to the new methods of DNA sequencing that are so brilliant you might think we stole the tech from aliens. If you're interested, check out the 454 Life Sciences Corporation or THIS ARTICLE for a scoop on one such new method that'll knock your socks off if you're an old-school biologist. Their process (click through and read the slides) is light-years beyond where we were only 5 years ago. The speaker we had reported that their lab was able to sequence massive pools of DNA from bacteria that lives in our intestines (well, monkey intestines, but close enough) and were able to determine that we have upwards of 1000 different species of bacteria living in us, mostly likely helping our system.
To summarize the sequencing method very briefly and un-technically (if you want the tech, read the site above): it manages to sequence thousands of little pieces of DNA at once... something we had to do one at a time or with the best machines, 96 at a time with a good bit of manual labor. Now we're talking thousands at once, on one machine, in one reaction, on one array. Holy smokes. A single lab worker could potentially sequence more in a day than 10 people working for a month.
With new technology such as this, the thought of sequencing a person's entire Genome in an hour is far closer than we could have ever dreamed. We're talking a couple years here. A decade ago that thought was unimaginable and downright crazy talk. And as the article said, it can also give us glimpses into genetic interactions between organisms in populations from a perspective we could never see before. See "Lateral DNA Transfer: Mechanisms and Consequences".
It would be an easy call if the risk was just to the person getting the transplant. Their body, their choice. However, communicable diseases like AIDS and bird flu got their start as zoonoses...
That's a good point. However, every time you eat a rare steak, you are almost certainly encountering multiple cow viruses in your mouth. (they'd likely be killed in your stomach FAST, but in your mouth, they're comfy.) But of course you never get one of them because they can't infect you and can't replicate in your cells. It's true that this study might provide the viruses more "motivation" to adaptively mutate, but the chances that they would successfully adapt to our cells is very unlikely. Using bird flu as an example, people can get infected (obviously) but only those who are in contact with HUGE amounts of virus and even in those cases, the virus is not contagious to other humans. Recent papers have proposed that the virus would need some 8 or so specific mutations to become a serious human pathogen. Since mutation is random, that makes the odds of that happening right up there with surviving air-born plane explosion. hehe. Sure, there's a risk, but it's slim to say the least.
I don't think this is such a small matter as you claim. The boundaries between two species have been weakened.
Biologists have always pointed out the similarities between human DNA and that of animals... but now there is a concrete... creature embodying these similarities. Yes, I realize that the human cells have not interbred with the sheep cells, but this is still a partly human creature, a chimera.
The ultimate goal of these studies will take us further away from a "sheep-man" and closer to a sheepish organ incubator. Stem cells become their ultimate tissues/organs through many steps, some of which we can recognize and manipulate even today. Heck, right down the hall from me, they're making neurons and next to them, they're making bone cells hoping to find treatments for things like osteogenesis imperfecta...see Mr. Glass in "Unbreakable":D... and of course the people who made these sheep would rather program the cells to JUST become a heart or JUST a liver for example. They don't want "sheep-human" freaks. That'd be a little hard to sell to their funding agency. hehe. So bottom line, a human liver does not a sheep-man make IMO.
People often assume that every scientific advance is a slippery slope, which is good to think so as to keep things reigned in. But in actuallity, Nobody's gonna go all Dr. Moreau on us. Some people cross the line and they lose funding or wind up getting new laws made and fast.
This post is too long. TO THE SHEEP-CAVE!
As a geneticist, this is very exciting, but not as revolutionary as you might think. This is not really a genetically engineered sheep, it is a hybrid, a "chimera". Injected stem cells from a human (from bone marrow) are introduced into a developing sheep such that they take root and join in the sheep's development, replicating and differentiating to form organ tissue which is of human origin. It's more like cell culture than genetic engineering and no one has any problem with cell culture. The mention of the viral concern is very important and could essentially kill or at least delay this whole project if it is not dealt with. Every human and every animal is constantly infected with scads of different viruses (from birth on) that stay with us and do little or no damage to us our whole lives. Recent studies have found that we produce enormous amounts of viral proteins constantly, some of which almost certainly BENEFIT us, odd as it may sound. However, it is not easily predicted what a virus comfortable in sheep might do in a human host. Bottom line however, if the options are risk or death, go with risk.
As a Christian, I've got no major problem with this and most Christians who really understand it will agree. We eat these animals and wear their skin and fur as clothing. If anything, this is a way to waste as little as possible. Anyone who has a problem with growing organs in animals better not be eating them or wearing leather... or taking medications, or wearing makeups, or using soap, or etc. etc. (All these things required extensive studies in animals before we ever saw them.) One sheep might feed a family for a week, but in this case, one sheep could save a person's life and save us all $$ that would be spent on anti-rejection drugs.
btw:
didn't God say to dominate nature for our own purposes, putting fear and terror into the hearts of all animals?
No, He didn't. He assigned us the job of caretaker of earth and its animals/everythings, essentially.
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Forgive me for getting excited about new technology in my field. And no, I do not have stock in 454. Geez, I'm a grad student, I barely have a penny to my name ;P I brought it up because it's useful in this field, pertains directly to the topic, and this is a place where all us nerds can get excited about this sort of thing.
Please tell me with a straight face that you think you would have thought up doing a thousand simultaneous PCR reactions in an oil emulsion on beads then sequencing off the beads using fluorescence on an array...and I'll eat my hat. heh. It's smrt.
Also, I'll give you, hands down, that you're right that the sequences would be shorter...let's say 5 times shorter. That'd be enough bases for most studies. Honestly, how often do you think 100 bases are gonna repeat letter for letter in the genome. Heck, the longest primer I ever had to order... for normal uses... was 45. And anyway, the sort of stuff you're sequencing using this method is not the same as what you'd use a capillary system for. We're not talking getting perfect sequences, we're talking getting enough data for stats to give us something new/interesting. It's not the be all and end all, but it's a step toward it. It's a tool for something we had poor tools for in the past, so it's a good tool.
Man, I just wanna be able to sequence all the viruses I make in one go. Anything that gets me closer to that is what I call cool. 454 might not be what I need, but it sure as heck is a step toward it.
We recently had a speaker here to introduced us to the new methods of DNA sequencing that are so brilliant you might think we stole the tech from aliens. If you're interested, check out the 454 Life Sciences Corporation or THIS ARTICLE for a scoop on one such new method that'll knock your socks off if you're an old-school biologist. Their process (click through and read the slides) is light-years beyond where we were only 5 years ago. The speaker we had reported that their lab was able to sequence massive pools of DNA from bacteria that lives in our intestines (well, monkey intestines, but close enough) and were able to determine that we have upwards of 1000 different species of bacteria living in us, mostly likely helping our system.
To summarize the sequencing method very briefly and un-technically (if you want the tech, read the site above): it manages to sequence thousands of little pieces of DNA at once... something we had to do one at a time or with the best machines, 96 at a time with a good bit of manual labor. Now we're talking thousands at once, on one machine, in one reaction, on one array. Holy smokes. A single lab worker could potentially sequence more in a day than 10 people working for a month.
With new technology such as this, the thought of sequencing a person's entire Genome in an hour is far closer than we could have ever dreamed. We're talking a couple years here. A decade ago that thought was unimaginable and downright crazy talk. And as the article said, it can also give us glimpses into genetic interactions between organisms in populations from a perspective we could never see before. See "Lateral DNA Transfer: Mechanisms and Consequences".
The ultimate goal of these studies will take us further away from a "sheep-man" and closer to a sheepish organ incubator. Stem cells become their ultimate tissues/organs through many steps, some of which we can recognize and manipulate even today. Heck, right down the hall from me, they're making neurons and next to them, they're making bone cells hoping to find treatments for things like osteogenesis imperfecta
People often assume that every scientific advance is a slippery slope, which is good to think so as to keep things reigned in. But in actuallity, Nobody's gonna go all Dr. Moreau on us. Some people cross the line and they lose funding or wind up getting new laws made and fast.
This post is too long.
TO THE SHEEP-CAVE!