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Researchers: Woolly mammoth genes nearly identical to elephant’s

Dec. 19, 2005 Courtesy Penn State University and World Science staff

The majestic woolly mammoth that roamed the Northern Hemisphere’s grassy plains before 10,000 years ago was 98.5 percent identical in its genes to the modern African elephant, researchers say.

The finds come from a study of mammoth bones from Siberia, conducted by researchers from McMaster University in Hamilton, Ontario, and other institutions.

The results shows that scientists are taking strides forward in sequencing ancient DNA, traditionally a tricky field, the researchers said. Ancient DNA tends to break up and mix with genetic material from other organisms, complicating the work.

The team’s report on the first sequences from the genome of a woolly mammoth is to appear in the Dec. 22 online edition of the research journal Science.

The “breakthrough” allows for first comparisons of this species with today’s African and Indian elephants, the researchers said.

Previously, researchers had been able to analyze some mammoth DNA, but only a minuscule fraction, according to the team. Scientists in the past had to rely on a special type of DNA from compartments within cells called the mitochondria. This DNA is easier to analyze because it contain 1,000 times more copies of genes than the rest of the DNA, which is in the cell nucleus. But the mitochondria contain a tiny proportion of the full variety of the genes.

In the new study, researchers said they identified 13 million letters of genetic code from the DNA of the cell nuclei of the mammoth, an animal some scientists believe humans may have hunted to extinction.

The researchers said they showed that the sequence of these letters almost matched that of African elephant DNA. That reflects the animals’ close evolutionary relationship, they added.

The project became possible through the discovery of well preserved remains in the permafrost, or permanently frozen ground, of northern Siberia, the researchers said. What also helped was a new high-efficiency gene sequencing technique that could cope with the heavily fragmented ancient DNA, taken from the creature’s jaws.