The researchers restored the structure of DNA from frozen blood cells with the help of eggs.
The resurrection of extinct animals remains a beautiful fantasy, not a working technology. For the cloning of a mammoth or other extinct species, almost perfect cells, whole nuclei and suitable eggs of nearby animals are needed. Ancient DNA usually comes to scientists in its worst part: fragments are damaged, the cells are dead, and biology, as usual, is in no hurry to adapt to human dreams of a jure park.
The researchers offered a more modest but much more realistic path. Instead of trying to bring back the whole organism, scientists “revived” one chromosome and checked whether such a chromosome can work inside a cell of another species. The paper was published in the journal Scientific Reports.
The team started with the nuclei of dead blood cells rats, which lasted more than a year in freezing. Scientists have injected the nuclei into unfertilized mouse eggs. Such a medium caused free rat DNA to collapse into chromosomes again. The researchers then extracted one chromosome and moved it to a fresh mouse egg, which was fertilized with a regular mouse sperm.
The resulting embryo was developed in the laboratory to the stage of blastocysts. At an early stage, the scientists isolated stem cells that carried a full mouse set of 40 chromosomes and one additional rat chromosome. Hybrid stem cells were then injected into normal mouse embryos. So there were chimeric mice with cells in which both mouse and rat DNA were present.
To check the work of the rat chromosome helped in advance built into the original cells mark GFP. Protein causes the fabric to glow green in special light. In the resulting mice, green areas were found in the brain, heart, muscles and intestines. Heart cells were also actively read the rat gene Hsp90ab1, which means that the foreign chromosome was not just preserved in the cells, but participated in the body.
The authors believe that the method can help to study the genes of long-disappeared species if scientists manage to find well-preserved material. The new work does not bring the appearance of live mammoths in zoos and does not solve the main problem of cloning of extinct animals. But the study shows a different way: not to collect an entire organism from DNA debris, but to check the work of individual chromosomes and genes in living cells.
For paleogenetics, this approach may be more important than effective conversations about the “resurrectation” of extinct species. One working chromosome is able to tell how the genes of the disappeared animal functioned, what proteins the cells produced and what biological mechanisms were preserved in the damaged genetic material. Before the walks of mammoths in the snow, the way is still huge, but scientists have a way to ask ancient DNA questions that used to simply not answer dead cells.
The resurrection of extinct animals remains a beautiful fantasy, not a working technology. For the cloning of a mammoth or other extinct species, almost perfect cells, whole nuclei and suitable eggs of nearby animals are needed. Ancient DNA usually comes to scientists in its worst part: fragments are damaged, the cells are dead, and biology, as usual, is in no hurry to adapt to human dreams of a jure park.
The researchers offered a more modest but much more realistic path. Instead of trying to bring back the whole organism, scientists “revived” one chromosome and checked whether such a chromosome can work inside a cell of another species. The paper was published in the journal Scientific Reports.
The team started with the nuclei of dead blood cells rats, which lasted more than a year in freezing. Scientists have injected the nuclei into unfertilized mouse eggs. Such a medium caused free rat DNA to collapse into chromosomes again. The researchers then extracted one chromosome and moved it to a fresh mouse egg, which was fertilized with a regular mouse sperm.
The resulting embryo was developed in the laboratory to the stage of blastocysts. At an early stage, the scientists isolated stem cells that carried a full mouse set of 40 chromosomes and one additional rat chromosome. Hybrid stem cells were then injected into normal mouse embryos. So there were chimeric mice with cells in which both mouse and rat DNA were present.
To check the work of the rat chromosome helped in advance built into the original cells mark GFP. Protein causes the fabric to glow green in special light. In the resulting mice, green areas were found in the brain, heart, muscles and intestines. Heart cells were also actively read the rat gene Hsp90ab1, which means that the foreign chromosome was not just preserved in the cells, but participated in the body.
The authors believe that the method can help to study the genes of long-disappeared species if scientists manage to find well-preserved material. The new work does not bring the appearance of live mammoths in zoos and does not solve the main problem of cloning of extinct animals. But the study shows a different way: not to collect an entire organism from DNA debris, but to check the work of individual chromosomes and genes in living cells.
For paleogenetics, this approach may be more important than effective conversations about the “resurrectation” of extinct species. One working chromosome is able to tell how the genes of the disappeared animal functioned, what proteins the cells produced and what biological mechanisms were preserved in the damaged genetic material. Before the walks of mammoths in the snow, the way is still huge, but scientists have a way to ask ancient DNA questions that used to simply not answer dead cells.
