Courtesy Penn State's Eberly College of Science
The woolly mammoth is the first extinct animal to have its DNA sequence deciphered.
The woolly mammoth is the first extinct animal to have its DNA sequence deciphered. Courtesy Penn State's Eberly College of Science
Stephan Schuster lab, Penn State
Scientists used the DNA from permafrost-preserved hair to determine the DNA sequence of a woolly mammoth.
Scientists used the DNA from permafrost-preserved hair to determine the DNA sequence of a woolly mammoth. Stephan Schuster lab, Penn State
Using DNA encased in hair shafts, researchers have determined the DNA sequence of a woolly mammoth. It's the first extinct mammal to have its sequence deciphered.
"Mammoths and elephants are, on the sequence level, very similar," says Stephan Schuster of Pennsylvania State University who led the sequencing team. "[There is a] 99.4 percent equivalence between the two."
Schuster's team used a variety of mammoth remains to conduct its study. Each was frozen in the Siberian permafrost, some for tens of thousands of years. The DNA came from the dead animal's hair.
"Unlike what you hear on CSI, you don't need to have a hair follicle to find DNA attached with hair," Schuster says. "We isolate DNA from the hair shaft."
A problem with analyzing DNA from ancient samples is that there's typically a lot of DNA from bacteria and viruses contaminating the sample that you have to get rid of.
"The way that we get rid of it is we shampoo and bleach the hair," Schuster says.
Not only does this make the hair soft and manageable, but what's left inside the hair shafts is almost exclusively mammoth DNA.
Schuster says the DNA is not the long strands found in living cells. It is millions of tiny fragments. But new sequencing machines can read those fragments, and new computer programs can stitch them together to form a complete sequence — or at least a nearly complete sequence.
It's tempting to speculate that with the DNA sequence in hand it might be possible to recreate an extinct mammoth using a mixture of genetic engineering and cloning. Molecular geneticist Tom Gilbert of the University of Copenhagen is skeptical, at least in the short term.
"I should warn upfront that I have a history of saying it's not possible, and then within months some technological breakthrough comes that makes me revise my opinion," says Gilbert.
He says the real value of having the sequence data is that it will help scientists understand how elephants evolved.