Precious Primates: Images of Chimeric Monkeys
Eternal_Knight 2012/01/08 09:11
Roku and HexCredit:
(c)OHSU Photos
Roku and Hex, the world's first chimeric monkeys, contain a mixture of cells representing at least 6 different genomes.
for those who dont lyk big topics read summary....
Eternal_Knight 2012/01/08 09:11
Roku and HexCredit:
(c)OHSU Photos
Roku and Hex, the world's first chimeric monkeys, contain a mixture of cells representing at least 6 different genomes.
for those who dont lyk big topics read summary....
Eternal_Knight 2012/01/08 09:41
They look like ordinary baby rhesus macaques, but Hex, Roku and Chimero are the world's first chimeric monkeys, each with cells from the genomes of as many as six rhesus monkeys.
Until now research on so-called chimeric animals, or those that have cells with different genomes, has been limited to mice; a recent procedure produced mice using cells from two dads.
The researchers turned to monkeys for more insight into the capabilities of embryonic stem cells. Most experiments on stem cell therapies are based on mice, and the researchers wanted to understand whether primate embryonic stem cells respond the same way as those of mice do.
To create the chimeric monkeys, researchers essentially glued together cells from individual rhesus monkey embryos and then implanting these mixed embryos into mama monkeys.
They look like ordinary baby rhesus macaques, but Hex, Roku and Chimero are the world's first chimeric monkeys, each with cells from the genomes of as many as six rhesus monkeys.
Until now research on so-called chimeric animals, or those that have cells with different genomes, has been limited to mice; a recent procedure produced mice using cells from two dads.
The researchers turned to monkeys for more insight into the capabilities of embryonic stem cells. Most experiments on stem cell therapies are based on mice, and the researchers wanted to understand whether primate embryonic stem cells respond the same way as those of mice do.
To create the chimeric monkeys, researchers essentially glued together cells from individual rhesus monkey embryos and then implanting these mixed embryos into mama monkeys.
Eternal_Knight 2012/01/08 09:42
The key was mixing cells from very early-stage embryos, or blastocysts, that consisted of just two to four cells each one of the cells still totipotent, capable of transforming into a whole animal as well as the placenta and other life-sustaining tissues. (This is in contrast to pluripotent stem cells, which can differentiate into any tissue type in the body, but not certain embryonic tissues or entire organisms.)
"The cells never fuse, but they stay together and work together to form tissues and organs," said Shoukhrat Mitalipov of the Oregon National Primate Research Center at Oregon Health & Science University. "The possibilities for science are enormous." [Images of the Chimeric Monkeys]
Try, try again
The researchers first tried creating chimeric monkeys using the process for chimeric mice. In this procedure, embryonic stem cells are injected into a host embryo after they have been cultured for as long as decades. These stem cells will mix with the host embryo's cells to produce tissues and organs and ultimately offspring. When these offspring are mated, the resulting offspring have cells derived solely from the implanted stem cells. If you were to pluck two cells from a chimeric mouse's body, you could get two different genomes complete sets of chromosomes and genetic information.
But the methods that work to create chimeric mice failed in rhesus monkeys, leading to offspring with cells only from the host embryo.
"Unfortunately that didn't work," Mitalipov told LiveScience in a telephone interview. "We produced offspring that way and they didn't show any contribution of stem cells." The stem cells seemed to have gotten lost somewhere, he said.
The researchers guessed that the culturing somehow had changed these embryonic stem cells. So they recovered stem cells from an embryo's inner cell mass (rather than from the freezer after being cultured) and, without culturing them, injected the stem cells into a host embryo.
Rather than one chimeric monkey infant, the result was two separate fetuses twins.
Finally, the researchers hit on a successful method, using early blastocysts that had split into no more than four separate cells. They took individual cells out of these clumps and aggregated them back together, mixing and matching between three and six individuals to create 29 new blastocysts. The researchers picked the 14 strongest-looking of them and implanted them in five surrogate mother monkeys.
All five got pregnant. Researchers terminated the pregnancies of three of them to test the fetuses for chimerism, and they found it. Soon after, the remaining two monkeys delivered twins (named Roku and Hex for the Japanese and Greek words for "six"
and a singleton, Chimero. All appear male, though testing on their cells reveals that they also contain individual female genomes.
The key was mixing cells from very early-stage embryos, or blastocysts, that consisted of just two to four cells each one of the cells still totipotent, capable of transforming into a whole animal as well as the placenta and other life-sustaining tissues. (This is in contrast to pluripotent stem cells, which can differentiate into any tissue type in the body, but not certain embryonic tissues or entire organisms.)
"The cells never fuse, but they stay together and work together to form tissues and organs," said Shoukhrat Mitalipov of the Oregon National Primate Research Center at Oregon Health & Science University. "The possibilities for science are enormous." [Images of the Chimeric Monkeys]
Try, try again
The researchers first tried creating chimeric monkeys using the process for chimeric mice. In this procedure, embryonic stem cells are injected into a host embryo after they have been cultured for as long as decades. These stem cells will mix with the host embryo's cells to produce tissues and organs and ultimately offspring. When these offspring are mated, the resulting offspring have cells derived solely from the implanted stem cells. If you were to pluck two cells from a chimeric mouse's body, you could get two different genomes complete sets of chromosomes and genetic information.
But the methods that work to create chimeric mice failed in rhesus monkeys, leading to offspring with cells only from the host embryo.
"Unfortunately that didn't work," Mitalipov told LiveScience in a telephone interview. "We produced offspring that way and they didn't show any contribution of stem cells." The stem cells seemed to have gotten lost somewhere, he said.
The researchers guessed that the culturing somehow had changed these embryonic stem cells. So they recovered stem cells from an embryo's inner cell mass (rather than from the freezer after being cultured) and, without culturing them, injected the stem cells into a host embryo.
Rather than one chimeric monkey infant, the result was two separate fetuses twins.
Finally, the researchers hit on a successful method, using early blastocysts that had split into no more than four separate cells. They took individual cells out of these clumps and aggregated them back together, mixing and matching between three and six individuals to create 29 new blastocysts. The researchers picked the 14 strongest-looking of them and implanted them in five surrogate mother monkeys.
All five got pregnant. Researchers terminated the pregnancies of three of them to test the fetuses for chimerism, and they found it. Soon after, the remaining two monkeys delivered twins (named Roku and Hex for the Japanese and Greek words for "six"
and a singleton, Chimero. All appear male, though testing on their cells reveals that they also contain individual female genomes.
Eternal_Knight 2012/01/08 09:43
Growing up chimeric
The monkeys were delivered by C-section. Their mothers rejected them, probably in response to the nonnatural method used to deliver them, so now they are being raised by a foster mama.
Researchers aren't yet sure whether Roku, Hex and Chimero will be able to reproduce. It takes rhesus macaques four to five years to reach sexual maturity.
There are no plans to create human chimeras and no need to, Mitalipov emphasized. This research by itself should help scientists in conducting biomedical research more relevant to humans, he said.
Chimeric mice, for instance, are used to produce genetically engineered "knock-out" mice that carry deletions of important genes. In that way, researchers can see firsthand what genes do or don't do.
The results may be useful in stem cell therapy, Mitalipov said. Researchers believe that stem cells cultured in Petri dishes could be transplanted into adult patients to treat conditions such as paralysis or Parkinson's disease.
"But this is based on mouse models," Mitalipov said. "We didn't know whether primates have this capacity."
The chimeric monkey study, reported today (Jan. 5) in the journal Cell, shows that primate cultured stem cells probably have some potential to differentiate, but they aren't comparable to in-vivo stem cells, or stem cells produced in the body, Mitalipov said.
"We cannot model everything in the mouse," Mitalipov said. "If we want to move stem cell therapies from the lab to clinics and from the mouse to humans, we need to understand what these primate cells can and can't do. We need to study them in humans, including human embryos."
Even though the researchers found success without culturing, cultured cells shouldn't be written off, said Richard Behringer, a geneticist at MD Anderson Cancer Center in Houston. The reason the cells didn't work in monkeys may be due to something in the laboratory process, not because of the cells themselves, Behringer told LiveScience.
"We know so little about the early embryology of our cells," Behringer said. "We know about the fertilization to the blastocyst stage because you can do that in vitro, but after that there's very little known about human embryology this is when a woman may not even know she's pregnant. Having the monkey model is useful to understand the early embryonic development, where the monkey can stand in for the human."
Growing up chimeric
The monkeys were delivered by C-section. Their mothers rejected them, probably in response to the nonnatural method used to deliver them, so now they are being raised by a foster mama.
Researchers aren't yet sure whether Roku, Hex and Chimero will be able to reproduce. It takes rhesus macaques four to five years to reach sexual maturity.
There are no plans to create human chimeras and no need to, Mitalipov emphasized. This research by itself should help scientists in conducting biomedical research more relevant to humans, he said.
Chimeric mice, for instance, are used to produce genetically engineered "knock-out" mice that carry deletions of important genes. In that way, researchers can see firsthand what genes do or don't do.
The results may be useful in stem cell therapy, Mitalipov said. Researchers believe that stem cells cultured in Petri dishes could be transplanted into adult patients to treat conditions such as paralysis or Parkinson's disease.
"But this is based on mouse models," Mitalipov said. "We didn't know whether primates have this capacity."
The chimeric monkey study, reported today (Jan. 5) in the journal Cell, shows that primate cultured stem cells probably have some potential to differentiate, but they aren't comparable to in-vivo stem cells, or stem cells produced in the body, Mitalipov said.
"We cannot model everything in the mouse," Mitalipov said. "If we want to move stem cell therapies from the lab to clinics and from the mouse to humans, we need to understand what these primate cells can and can't do. We need to study them in humans, including human embryos."
Even though the researchers found success without culturing, cultured cells shouldn't be written off, said Richard Behringer, a geneticist at MD Anderson Cancer Center in Houston. The reason the cells didn't work in monkeys may be due to something in the laboratory process, not because of the cells themselves, Behringer told LiveScience.
"We know so little about the early embryology of our cells," Behringer said. "We know about the fertilization to the blastocyst stage because you can do that in vitro, but after that there's very little known about human embryology this is when a woman may not even know she's pregnant. Having the monkey model is useful to understand the early embryonic development, where the monkey can stand in for the human."
Eternal_Knight 2012/01/08 10:00
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA.
in easy words,
Life is specified by genomes. Every organism, including humans, has a genome that contains all of the biological information needed to build and maintain a living example of that organism. The biological information contained in a genome is encoded in its deoxyribonucleic acid (DNA) and is divided into discrete units called genes. Genes code for proteins that attach to the genome at the appropriate positions and switch on a series of reactions called gene expression.
_rOcK_: whats genomes ??
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA.
in easy words,
Life is specified by genomes. Every organism, including humans, has a genome that contains all of the biological information needed to build and maintain a living example of that organism. The biological information contained in a genome is encoded in its deoxyribonucleic acid (DNA) and is divided into discrete units called genes. Genes code for proteins that attach to the genome at the appropriate positions and switch on a series of reactions called gene expression.
Eternal_Knight 2012/01/08 10:13
more pics wit summary...
ChimeroCredit: (c) OHSU Photos
Chimero, a third chimeric monkey produced by scientists. The researchers combined cells from 6 different rhesus monkeys, male and female, into an embryo to implant into a surrogate mother monkey. The results are Hex, Roku and Chimero, now all about six months old and healthy.
Chimeric BlastocystCredit: (c) OHSU Photos
An example of a chimeric blastocyst formed from the cells of six different monkeys, rather than the traditional two (mom and dad).
Two of a KindCredit: (c) OHSU Photos
Roku and Hex cuddle a stuffed toy. The chimeric monkeys were born via c-section. Monkey mothers often reject their babies after a c-section, so a monkey foster mom is feeding and caring for the chimeras.
[img=http://i.livescience.com/images/i/23197/i02/roku-120105.jpg]
Baby RokuCredit: (c) OHSU Photos
Baby Roku calls out during a photo shoot. The monkeys are an important step in stem cell research, according to scientists. Most stem cell work is done in mice, which respond differently than primates to embryonic manipulations.
[img=http://i.livescience.com/images/i/23198/i02/roku-hex2-120105.jpg]
Pair of SixesCredit: (c) OHSU Photos
"Roku" means "six" in Japanese, and "Hex" is the Greek prefix meaning "six."
[img=http://i.livescience.com/images/i/23199/i02/roku2-120105.jpg]
Hex Hangs OnCredit: (c) OHSU Photos
The monkeys' cells are a mixture of male or female, though externally each appears to be either male or female.
[img=http://i.livescience.com/images/i/23200/i02/roku3-120105.jpg]
Cuddly MonkeyCredit: (c) OHSU Photos
Roku gets cuddly. Rhesus monkeys take four to five years to mature sexually, so researchers won't know whether the chimeras can reproduce until then.
[img=http://i.livescience.com/images/i/23202/i02/roku-hex3-120105.jpg]
Hex & RokuCredit: (c) OHSU Photos
Researchers reported the birth of Chimera, Hex & Roku on Jan. 20 in the journal Cell.
[img=http://i.livescience.com/images/i/23204/i02/chimero2-120105.jpg]
Cute ChimeroCredit: (c) OHSU Photos
The monkeys, including Chimero, shown here, are now residing with their foster mom.
more pics wit summary...
ChimeroCredit: (c) OHSU Photos
Chimero, a third chimeric monkey produced by scientists. The researchers combined cells from 6 different rhesus monkeys, male and female, into an embryo to implant into a surrogate mother monkey. The results are Hex, Roku and Chimero, now all about six months old and healthy.
Chimeric BlastocystCredit: (c) OHSU Photos
An example of a chimeric blastocyst formed from the cells of six different monkeys, rather than the traditional two (mom and dad).
Two of a KindCredit: (c) OHSU Photos
Roku and Hex cuddle a stuffed toy. The chimeric monkeys were born via c-section. Monkey mothers often reject their babies after a c-section, so a monkey foster mom is feeding and caring for the chimeras.
[img=http://i.livescience.com/images/i/23197/i02/roku-120105.jpg]
Baby RokuCredit: (c) OHSU Photos
Baby Roku calls out during a photo shoot. The monkeys are an important step in stem cell research, according to scientists. Most stem cell work is done in mice, which respond differently than primates to embryonic manipulations.
[img=http://i.livescience.com/images/i/23198/i02/roku-hex2-120105.jpg]
Pair of SixesCredit: (c) OHSU Photos
"Roku" means "six" in Japanese, and "Hex" is the Greek prefix meaning "six."
[img=http://i.livescience.com/images/i/23199/i02/roku2-120105.jpg]
Hex Hangs OnCredit: (c) OHSU Photos
The monkeys' cells are a mixture of male or female, though externally each appears to be either male or female.
[img=http://i.livescience.com/images/i/23200/i02/roku3-120105.jpg]
Cuddly MonkeyCredit: (c) OHSU Photos
Roku gets cuddly. Rhesus monkeys take four to five years to mature sexually, so researchers won't know whether the chimeras can reproduce until then.
[img=http://i.livescience.com/images/i/23202/i02/roku-hex3-120105.jpg]
Hex & RokuCredit: (c) OHSU Photos
Researchers reported the birth of Chimera, Hex & Roku on Jan. 20 in the journal Cell.
[img=http://i.livescience.com/images/i/23204/i02/chimero2-120105.jpg]
Cute ChimeroCredit: (c) OHSU Photos
The monkeys, including Chimero, shown here, are now residing with their foster mom.
Someone 2012/01/10 14:40
Fine - interesting topic. There is some cases of Human chimeras too. In 1953 a human chimera was reported in the British Medical Journal. A woman was found to have blood containing two different blood types. Apparently this resulted from cells from her twin brother living in her body. More recently, a study found that such blood group chimerism is not rare. Another report of a human chimera was published in 1998, where a male human had some partially-developed female organs due to chimerism. He was conceived by in-vitro fertilization.
Fine - interesting topic. There is some cases of Human chimeras too. In 1953 a human chimera was reported in the British Medical Journal. A woman was found to have blood containing two different blood types. Apparently this resulted from cells from her twin brother living in her body. More recently, a study found that such blood group chimerism is not rare. Another report of a human chimera was published in 1998, where a male human had some partially-developed female organs due to chimerism. He was conceived by in-vitro fertilization.
Eternal_Knight 2012/01/10 16:54
had read about first case.. ..
Vipul: Fine - interesting topic. There is some cases of Human chimeras too. In 1953 a human chimera was reported in the British Medical Journal. A woman was found to have blood containing two different blood types. Apparently this resulted from cells from her twin brother living in her body. More recently, a study found that such blood group chimerism is not rare. Another report of a human chimera was published in 1998, where a male human had some partially-developed female organs due to chimerism. He was conceived by in-vitro fertilization.
had read about first case.. ..
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