Paleoanthropologist seems quite sure that hybrid elephant embryo with wooly mammoth characteristics will not be created within two years
by noreply@blogger.com (brian wang) from NextBigFuture.com on (#2DC98)
John Hawkes has that he does not believe that a wooly mammoth embyro will be created within two years.
George Church indicated that
45 mammoth-like edits of DNA have been spliced into the Asian elephant genome. "We're working on ways to evaluate the impact of all these edits," says Church. "The list of edits affects things that contribute to the success of elephants in cold environments. We already know about ones to do with small ears, subcutaneous fat, hair and blood."
Church says the next step would be to produce a hybrid embryo, although in reality this would really be more like an elephant embryo carrying a handful of mammoth genetic traits. "We're not there yet, but it could happen in a couple of years."
Church's objective is to create a more mammoth-like, hardier breed of Asian elephants, which are significantly more endangered than their African cousins. Such elephants could have a wider variety of ecosystems to choose from, and wouldn't be trapped in a rapidly shrinking range of habitats.
Note - creating a modified Asian elephant could be done by modifying the DNA and creating the embyro and then having a regular Asian elephant carry it to term.
If the gene-editing technique works, Church said it could be applied to other threats facing a wide variety of species: Frogs and salamanders could be genetically modified to make them impervious to the pathogens that are killing them off. Mosquitoes have already been modified in the lab to keep them from transmitting malaria, to cut down on breeding, or to keep the female bugs from flying.
Church acknowledged that species engineering has been criticized as costing too much and posing too many risks, especially when other environmental remedies are available. "I don't think it's an either-or thing," he said. "It's like saying we should invest in iron lungs rather than a polio vaccine, or in kidney dialysis rather than kidney transplants."
George Church's team has used "oligo synthesizers" like this to produce sequences that haven't existed inside living organisms for some 4,000 years, reconstructing lines of code extracted from the preserved bones, blood and flesh of Elephas primigenius. The woolly mammoth.
By sequencing those found fragments of DNA, scientists have been piecing together a full genome for the lost megafauna, which runs to nearly five billion base pairs - dwarfing that of humans.
Researchers can't yet print out or stitch together a genome anywhere near that long, but Church and others exploring de-extinction are pursuing a different route, which draws on those improving editing tools.
They're comparing the mammoth genomes to those of its closest living relative, the Asian elephant. The hope is they can print out the strands that differ, paste them into the right spots, insert that into an embryonic cell and implant it into the uterus of an elephant.
Genome editing is delicate work. The longer the strands and the more insertion points, the greater the chance that something will go wrong along the way.
Church has homed in on the woolly mammoth because he thinks it presents the best opportunity for success. There are relatively few differences, fewer in fact than between the Asian elephant and its present-day African cousin.
Church noted that the return of the passenger pigeon, which used to compete vigorously for food with tick-carrying rodents, could tamp down the surge of Lyme disease in this nation.
It is also believed that the woolly mammoth stomped down snow and ate away dark vegetation that absorbed heat in the Arctic tundra. He said that returning the creature in sufficient numbers may help protect the thawing permafrost, which sequesters more carbon dioxide than all of the rain forests combined.
John Hawkes was apparently worked up that over 60 articles got written and most of those ignored the details of what Church stated.
* elephants have gestation periods of 660 days. So no baby from the hybrid-embyro
* not a full mammoth because that would take 4000+ edits
* also no artificial womb to carry an elephant embryo to term
Partial Artificial mouse womb
They are already capable of growing a mouse embryo in an artificial womb for 10 days"-"halfway through a mouses 20 day gestation period.
John Hawkes notes
Previous experiments from other labs have successfully brought embryos more than 10 days into development by implanting them on a three-dimensional scaffold of endometrial cells and nutrients in culture. That work isn't from the 1980s, it was going on ten years ago and may still be underway in various labs, reviewed by Bulletti and colleagues (2011). In those experiments, after a certain stage of development, the ex vivo mice failed to grow normally and ultimately they died well before their 20-day gestation was complete. Maybe research will find some way around those problems, but for the moment this kind of approach will only yield early-stage embryos.
Elephants have a 22-month gestation length. At birth, elephants weigh 200 pounds. An elephant-sized artificial uterus would require either an enormous surface area of engineered tissue for placental attachment, or some kind of placenta replacement. Placenta replacement may not be impossible: In one experiment, a goat fetus was kept alive for more than a week by perfusing blood through the umbilicus supplemented with oxygen and nutrients. But that's far from a full-term gestation. Doctors have a lot of experience with extreme measures for nutrition and oxygen supplementation in cases of premature human infants.
If an effective artificial uterus were invented, it would be a massively more important story than Church's mammoth gene transfer project. The technical challenges are much greater, and the human benefits of such technology would be enormous.
Read more
George Church indicated that
45 mammoth-like edits of DNA have been spliced into the Asian elephant genome. "We're working on ways to evaluate the impact of all these edits," says Church. "The list of edits affects things that contribute to the success of elephants in cold environments. We already know about ones to do with small ears, subcutaneous fat, hair and blood."
Church says the next step would be to produce a hybrid embryo, although in reality this would really be more like an elephant embryo carrying a handful of mammoth genetic traits. "We're not there yet, but it could happen in a couple of years."
Church's objective is to create a more mammoth-like, hardier breed of Asian elephants, which are significantly more endangered than their African cousins. Such elephants could have a wider variety of ecosystems to choose from, and wouldn't be trapped in a rapidly shrinking range of habitats.
Note - creating a modified Asian elephant could be done by modifying the DNA and creating the embyro and then having a regular Asian elephant carry it to term.
If the gene-editing technique works, Church said it could be applied to other threats facing a wide variety of species: Frogs and salamanders could be genetically modified to make them impervious to the pathogens that are killing them off. Mosquitoes have already been modified in the lab to keep them from transmitting malaria, to cut down on breeding, or to keep the female bugs from flying.
Church acknowledged that species engineering has been criticized as costing too much and posing too many risks, especially when other environmental remedies are available. "I don't think it's an either-or thing," he said. "It's like saying we should invest in iron lungs rather than a polio vaccine, or in kidney dialysis rather than kidney transplants."
George Church's team has used "oligo synthesizers" like this to produce sequences that haven't existed inside living organisms for some 4,000 years, reconstructing lines of code extracted from the preserved bones, blood and flesh of Elephas primigenius. The woolly mammoth.
By sequencing those found fragments of DNA, scientists have been piecing together a full genome for the lost megafauna, which runs to nearly five billion base pairs - dwarfing that of humans.
Researchers can't yet print out or stitch together a genome anywhere near that long, but Church and others exploring de-extinction are pursuing a different route, which draws on those improving editing tools.
They're comparing the mammoth genomes to those of its closest living relative, the Asian elephant. The hope is they can print out the strands that differ, paste them into the right spots, insert that into an embryonic cell and implant it into the uterus of an elephant.
Genome editing is delicate work. The longer the strands and the more insertion points, the greater the chance that something will go wrong along the way.
Church has homed in on the woolly mammoth because he thinks it presents the best opportunity for success. There are relatively few differences, fewer in fact than between the Asian elephant and its present-day African cousin.
Church noted that the return of the passenger pigeon, which used to compete vigorously for food with tick-carrying rodents, could tamp down the surge of Lyme disease in this nation.
It is also believed that the woolly mammoth stomped down snow and ate away dark vegetation that absorbed heat in the Arctic tundra. He said that returning the creature in sufficient numbers may help protect the thawing permafrost, which sequesters more carbon dioxide than all of the rain forests combined.
John Hawkes was apparently worked up that over 60 articles got written and most of those ignored the details of what Church stated.
* elephants have gestation periods of 660 days. So no baby from the hybrid-embyro
* not a full mammoth because that would take 4000+ edits
* also no artificial womb to carry an elephant embryo to term
Partial Artificial mouse womb
They are already capable of growing a mouse embryo in an artificial womb for 10 days"-"halfway through a mouses 20 day gestation period.
John Hawkes notes
Previous experiments from other labs have successfully brought embryos more than 10 days into development by implanting them on a three-dimensional scaffold of endometrial cells and nutrients in culture. That work isn't from the 1980s, it was going on ten years ago and may still be underway in various labs, reviewed by Bulletti and colleagues (2011). In those experiments, after a certain stage of development, the ex vivo mice failed to grow normally and ultimately they died well before their 20-day gestation was complete. Maybe research will find some way around those problems, but for the moment this kind of approach will only yield early-stage embryos.
Elephants have a 22-month gestation length. At birth, elephants weigh 200 pounds. An elephant-sized artificial uterus would require either an enormous surface area of engineered tissue for placental attachment, or some kind of placenta replacement. Placenta replacement may not be impossible: In one experiment, a goat fetus was kept alive for more than a week by perfusing blood through the umbilicus supplemented with oxygen and nutrients. But that's far from a full-term gestation. Doctors have a lot of experience with extreme measures for nutrition and oxygen supplementation in cases of premature human infants.
If an effective artificial uterus were invented, it would be a massively more important story than Church's mammoth gene transfer project. The technical challenges are much greater, and the human benefits of such technology would be enormous.
Read more