Experts are one step closer to bringing the woolly mammoth back to life thanks to the first-ever 3D reconstruction of chromosomes collected from ancient skin.
About 52,000 years ago, a woolly mammoth was freeze-dried by weather conditions shortly after its death, leaving its DNA in a glassy state.
The exceptionally well-preserved specimen was unearthed in northeastern Siberia in 2018, allowing a team of international scientists to analyze the skin tissue.
Now they have successfully managed to make a detailed reconstruction of the extinct species’ chromosomes: thread-like structures made up of DNA.
It’s the first time scientists have been able to do this with such an old sample.
Experts are one step closer to bringing the woolly mammoth back to life thanks to the first-ever 3D reconstruction of chromosomes collected from ancient skin
About 52,000 years ago, a woolly mammoth was freeze-dried by the weather shortly after it died, preserving its DNA in a glassy state. The unusually well-preserved specimen was unearthed in northeastern Siberia in 2018, allowing a team of international scientists to analyze its skin tissue
And they said it could boost efforts to ‘eradicate’ the woolly mammoth, as its DNA could be compared to that of modern elephants.
Currently, a company called Colossal Biosciences is leading the effort to bring the woolly mammoth back to life.
Their strategy is to take the genome of an Asian elephant and make a lot of small changes to the DNA.
An Asian elephant then carries the young to term, producing an elephant with many of the adaptations woolly mammoths need to thrive in the cold.
The team behind the new discovery says the genetic information preserved in this fossil is much more detailed than most ancient DNA fragments found so far.
Not only could they see which genes were present in the fossil, but also roughly which ones were active and which were ‘switched off’ – something they had never seen before.
According to Erez Lieberman Aiden, one of the study’s authors from Baylor College of Medicine in Texas, this will help efforts to eradicate the mammoth by giving scientists insight into which genes and sequences they need to “edit” in an elephant’s genome to turn it into something resembling the extinct species.
“Like DNA, whole chromosomes were thought to be fragile objects that could not survive long outside a living organism,” he said.
The research could boost efforts to ‘drive the woolly mammoth to extinction’ by comparing it to the DNA of modern elephants
The team behind the new discovery say the genetic information preserved in this fossil is much more detailed than most ancient DNA fragments that have been found. They could not only see the genes that were present in the fossil, but also roughly which ones were active and which were ‘switched off’ – something they had never seen before
‘But under the right conditions, chromosomes can indeed survive for a very long time.
‘And this surprise makes many things possible, like assembling extinct genomes, or looking at the tissue of a woolly mammoth and seeing which genes are on and which are off, or studying the loops of DNA that turn genes on and off.
“The overall plan for de-extinction is to use the knowledge we have gained from DNA sequencing about the mammoth to evolve an elephant-like life form that resembles the mammoth in important ways.”
Although versions of this plan have been around for some time, large gaps in knowledge about the woolly mammoth genome have been a “potential spanner in the works,” for example regarding the number of chromosome pairs.
“The good news for de-extinction is that we don’t have to worry about a huge amount of potential problems because the overall genome structure of the two species is quite similar,” Dr Aiden said.
So it really does look like local edits [to DNA] could take us very far.’
“The good news for de-extinction is that we don’t have to worry about whole sets of potential wrenches because the overall genome structure of the two species is quite similar,” said Dr Aiden
According to him, their discovery also helps determine exactly what processes are needed to turn an Asian elephant into a mammoth.
“For example, we can now look at the skin of a woolly mammoth and using these fossil chromosomes we can see for the first time which genes were active in the skin of a woolly mammoth and were not active in the skin of an elephant, and vice versa,” he added.
‘Now we can better understand which genes and sequences we need to target to make an elephant woolly, and which sequences are less important for that trait.’
Although the method used in this study is based on exceptionally well-preserved fossils, the researchers are optimistic that it can also be used to study other ancient DNA specimens, such as Egyptian mummies.
Other authors include researchers from the University of Copenhagen, the Centre Nacional d’Anàlisi Genòmica and the Centre for Genomic Regulation in Spain.
The findings were published in the journal Cell.