Wow. Don't you think that "So don't give me your HCI spiel" is a little harsh for a kid who was just trying to say that reputable schools are beginning to recognize that end-user frustration is reaching levels that justify creating a new BS undergraduate program?
Remember when they came out with the funky iMac cases with weird designs and colors. Well, they have expressed the belief that the old iMac was very successful, so maybe they are just going to follow the lead of their previous success. If giving the old iMac model color and design helped to generate or sustain robust sales, maybe they are adding the ability to change the outside design and color of the new iMacs through the software. I hope that this is not one of the big announcements at MacWorld, but it sounds pretty cool to me.
The answer is that some body cells have an enzyme called telomerase that adds telomeres back to the ends of the chromosomes. This enzyme is found active in cell such as sperm, egg, and cancer. In fact, telomerase allows cancer cells to divide almost infinitely and spread throughout the body.
Geron recognized the power of telomerase and has devoted a great deal of research into how it works. The interesting thing is that to address the problem of "old" DNA in cloning, telomerase could be used to add telomeres and rejuvenate the chromosomes. Also, an anti-telomerase, which is an enzyme that turns the activity of telomerase off, can be used in cancer cells to make them mortal again. If cancer cells can not divide forever they are unable to spread as quickly and devastatingly through the body and have been proven to be more sensitive to chemotherapy.
There is an enzyme which is active in cancer cells that allows them to be immortal and spread through the body. That enzyme is called Telomerase. Mitosis cuts the a repeating TTAGGG (Telomere) from the end of chromosomes each time a cell divides, because the transcribing protein binds to the top TTAGGG and transcribes only the repeating pieces below. Telomerase adds TTAGGG to the ends of the chromosomes.
From the articles that I have read on this very suspect claim it hints that they used the same method as was used with Dolly. I did my Senior Thesis on Geron, the company that purchased the rights to the methode that cloned Dolly; therefore, I have a fare understanding of what is involved with Nuclear Transfer. Although I am not an expert and have never attempted the process in a lab, I have read enough to know that it is a terrible idea to try this on humans at this point.
There is a easy to understand FAQ on the Roslin Institute web site written by the people that actually cloned Dolly. Here are some interesting highlights:
Are clone embryos like IVF and normal pregnancies?
Not so far. The scientists at the Roslin Institute, who pioneered this work, have repeatedly found that the clone foetuses grow much larger than normal ones, and there is a much higher chance of the pregnancy failing, of stillbirth, or of forced Caesarean sections. Dolly was the one successful pregnancy of more than 277 embryos.
What do the experts think?
"I think you are always going to run the risk of having aging DNA," says Professor Lord Robert Winston, an IVF pioneer. "I would hate to think of a child of mine being cloned because I think it would be very likely he would have an accelerated aging process."
Dr Jamie Grifo, director of the division of reproductive endocrinology at New York University, says: "Cloning is no better than any of the other treatments that are out there. A biological child is the husband's sperm, the wife's egg. A clone is not a biological child."
Dr David Stevens, of the Christian Medical and Dental Society, asks: "Are we really willing to sacrifice hundreds of embryos - developing human beings - to make one baby who may suffer monstrous consequences?"
So, there are two very important points that must be stressed. The first is that there is a high percentage probability of genetic defect supported by further experiments. Think of the threat of genetic abnormalities in a fetus that managed to survive as much higher than if you had children with immediate family members.
The second is that each cell has an "age" that is determined by the number of times that a cell has divided. If you use DNA from adult cells that have divided many times, than all of the cells cloned from that DNA will be older. A cell can only dived around 50 times before it dies at which point you reach the Hayflick Limit. Although there are ways to prolong the life of cell lines similar to the way cancer spreads through a body, I doubt that this group of individuals thought of adding telomeres back to the end of the chromosomes that would be used to clone a human baby.
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Probably should have spelled out Bachelor of Science...
Wow. Don't you think that "So don't give me your HCI spiel" is a little harsh for a kid who was just trying to say that reputable schools are beginning to recognize that end-user frustration is reaching levels that justify creating a new BS undergraduate program?
Remember when they came out with the funky iMac cases with weird designs and colors. Well, they have expressed the belief that the old iMac was very successful, so maybe they are just going to follow the lead of their previous success. If giving the old iMac model color and design helped to generate or sustain robust sales, maybe they are adding the ability to change the outside design and color of the new iMacs through the software. I hope that this is not one of the big announcements at MacWorld, but it sounds pretty cool to me.
Very intellegent question.
The answer is that some body cells have an enzyme called telomerase that adds telomeres back to the ends of the chromosomes. This enzyme is found active in cell such as sperm, egg, and cancer. In fact, telomerase allows cancer cells to divide almost infinitely and spread throughout the body.
Geron recognized the power of telomerase and has devoted a great deal of research into how it works. The interesting thing is that to address the problem of "old" DNA in cloning, telomerase could be used to add telomeres and rejuvenate the chromosomes. Also, an anti-telomerase, which is an enzyme that turns the activity of telomerase off, can be used in cancer cells to make them mortal again. If cancer cells can not divide forever they are unable to spread as quickly and devastatingly through the body and have been proven to be more sensitive to chemotherapy.
There is an enzyme which is active in cancer cells that allows them to be immortal and spread through the body. That enzyme is called Telomerase. Mitosis cuts the a repeating TTAGGG (Telomere) from the end of chromosomes each time a cell divides, because the transcribing protein binds to the top TTAGGG and transcribes only the repeating pieces below. Telomerase adds TTAGGG to the ends of the chromosomes.
From the articles that I have read on this very suspect claim it hints that they used the same method as was used with Dolly. I did my Senior Thesis on Geron, the company that purchased the rights to the methode that cloned Dolly; therefore, I have a fare understanding of what is involved with Nuclear Transfer. Although I am not an expert and have never attempted the process in a lab, I have read enough to know that it is a terrible idea to try this on humans at this point.
There is a easy to understand FAQ on the Roslin Institute web site written by the people that actually cloned Dolly. Here are some interesting highlights:
Are clone embryos like IVF and normal pregnancies?
Not so far. The scientists at the Roslin Institute, who pioneered this work, have repeatedly found that the clone foetuses grow much larger than normal ones, and there is a much higher chance of the pregnancy failing, of stillbirth, or of forced Caesarean sections. Dolly was the one successful pregnancy of more than 277 embryos.
What do the experts think? "I think you are always going to run the risk of having aging DNA," says Professor Lord Robert Winston, an IVF pioneer. "I would hate to think of a child of mine being cloned because I think it would be very likely he would have an accelerated aging process." Dr Jamie Grifo, director of the division of reproductive endocrinology at New York University, says: "Cloning is no better than any of the other treatments that are out there. A biological child is the husband's sperm, the wife's egg. A clone is not a biological child." Dr David Stevens, of the Christian Medical and Dental Society, asks: "Are we really willing to sacrifice hundreds of embryos - developing human beings - to make one baby who may suffer monstrous consequences?"
So, there are two very important points that must be stressed. The first is that there is a high percentage probability of genetic defect supported by further experiments. Think of the threat of genetic abnormalities in a fetus that managed to survive as much higher than if you had children with immediate family members.
The second is that each cell has an "age" that is determined by the number of times that a cell has divided. If you use DNA from adult cells that have divided many times, than all of the cells cloned from that DNA will be older. A cell can only dived around 50 times before it dies at which point you reach the Hayflick Limit. Although there are ways to prolong the life of cell lines similar to the way cancer spreads through a body, I doubt that this group of individuals thought of adding telomeres back to the end of the chromosomes that would be used to clone a human baby.