Five millennia on, Iceman of Bolzano gives up DNA secrets

Oetzi's genetic code could shed light on hereditary diseases such as diabetes, hypertension and cancer.

Michael Day
Monday 02 August 2010 00:00 BST
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Nearly 20 years after the dead man's head was found peeping from a melting Alpine glacier, investigators have finally seen fit to contact his relatives.

This doesn't indicate sloth on the part of the Italian authorities, but instead, advances in DNA technology that may lead scientists to living descendants of the South Tyrol's 5,300-year-old mummified man.

Oetzi the iceman, who today resides in a sterile, glass box at 7C in 100 per cent humidity, is by far the oldest mummified person ever found – those of ancient Egypt are at least 1,000 years younger. He is the permanent star exhibit in a museum in the town of Bolzano.

In this grotesque but timeless state, researchers have been able to extract DNA from a bone in his pelvis. And this week it was announced they had sequenced his entire genome and that the hunt was now on to find Oetzi's descendants – and evidence of genetic changes that have occurred since Neolithic times.

With Oetzi's complete genetic map for their perusal, Dr Albert Zink, the director of the Iceman Institute in Bolzano, and his colleagues said it might also be possible to shed light on hereditary aspects of diseases such as diabetes, hypertension and cancer. "There are key gene mutations that we know are associated with diseases such as cancer and diabetes and we want to see if Oetzi had them or whether they arose more recently," he said.

Earlier studies had decoded the iceman's mitochondrial DNA, but these tiny gene sequences, which are passed by mothers to their children, provided only limited information, although they did suggest that if Oetzi still had relatives in the Alps, there weren't that many of them. Dr Zink, is now working with Carsten Pusch from the Institute of Human Genetics at the University of Tübingen and Andreas Keller from Febit, a bio-tech firm in Heidelberg, to share resources and knowledge, and hopefully speed the arrival of research findings in time for next year's 20th annivesary of Oetzi's discovery.

"From comparisons based on the mitochondrial DNA we weren't able to find any relatives in the region. But with the entire genome, there's a good chance we might," said Dr Zink. "We're at the start of a big and very exciting project. I think Oetzi is going to provide us with a lot of information."

Oetzi has proved a goldmine for scientists since he was discovered in the snow on 19 September 1991, over 3,000m up on the Italian-Austrian border. Anthropologists learnt from the degree and positioning of wear and tear in Oetzi's joints that some Neolithic people, contrary to previous theories, spent most if not all their lives high in the mountains. Oetzi, who was about 5ft 5in tall, weighed about 59 kg and was probably around 45 years old when he died, had also been around the block a few times. He had three broken ribs, a nasty cut on his hand, the intestinal parasite whipworm and fleas. Scientist were also able to piece together his attire – a goatskin loincloth, leather leggings, a goatskin coat and a cloak of grass stitched together with animal sinews. He wore a bearskin cap and leather shoes stuffed with grass to keep his feet warm. But Oetzi might be considered ahead of his time in the style stakes. While today's young Italians race to cover their legs, necks and elbows in ugly spider web tattoos, Oetzi had beaten them to it with, around 57, rather more tasteful, carbon tattoos consisting of dots and lines.

It was the nature of Oetzi's death, though, that has most captured the imagination. Initially, it was thought that he froze to death in a blizzard. But CT scans have since revealed that his body contained a flint-headed arrow that entered through his shoulder stopping just short of his left lung, but rupturing the key blood vessel carrying blood from his heart to his left arm. Oetzi was murdered.

"Judging by the degree of damage to a major artery, it's almost certain that he bled to death," said Dr Zink, "and quickly, too."

Traces of blood from four different people on the Otzi's dagger suggest an earlier or ongoing skirmish might have been related to the fatal wound, perhaps with the iceman taking an arrow in the back while fleeing his adversaries -- members, possibly of a rival tribe.

The absence of an arrow shaft has led one researcher, Dr Eduard Egarter Vigl, a pathologist in Bolzano, to suggest the killer had removed it to cover his tracks, since arrows can be identified easily.

More prosaic controversies have arisen, too, following the discovery of his corpse in the Schnalstal glacier. At first, it wasn't clear in which country Oetzi had been discovered. But surveys in October 1991 showed that the body had been found 93 meters inside Italian territory, and so the Italian province grabbed Oetzi. And the tourist board made a killing. So too did the woman who found him.

Although it wasn't until May this year that the acrimonious dispute over the finder's fee was finally decided. Authorities announced they would meet the €175,000 (£150,000) demand of the German couple, Helmut and Erika Simon, who found the Iceman. Mrs Simon, by now a widow, argued that the mummy had earned the city of Bolzano tens of million of euros – and that she deserved more than the €5,000 she'd originally been offered for discovering the corpse.

Several others have tried to get the paws on the money. One, a Swiss woman, said she spat on the Iceman to stake her claim. Her DNA was not found on the body, however.

Another, a Slovenian actress, claimed she beat the German couple to the scene by about five minutes and had asked them to take photos of the corpse. But she could produce no one to corroborate her account.

The discovery of Oetzi has also spawned a host of exotic theories regarding the circumstances behind his violent death. One space technology professor has suggested that evidence of an asteroid landing in the area in that period might be linked to the Iceman's demise. He wondered whether Oetzi had been a powerful figure and was used as a ritual sacrifice in order to appease the gods who'd sent the terrifying extra-terrestrial object.

Another theory contested by residents of this formerly Austrian region, who see the Iceman as their forefather, claims he was cast out from his community because a low sperm count rendered him childless.

"I'm not sure whether we'll be able to say whether that's true or not with the DNA sequencing," said Dr Zink. "But there are lots of questions that we might be able to answer."

But staring at poor Oetzi's gnarled, brown corpse, you can't help wondering if the most obvious question is ethical rather than scientific: how recently does someone have to have died before they're entitled to a proper burial - instead of being left in a glass cage like a gooey prop from a horror film, for people to gawp at?

"There has been some discussion on this," says Dr Zink, "and it's a fair point. But this man is 5,300 years old. We do treat him with respect; we look after the body very, very carefully, and he provides us with lot of valuable information. And besides, even if we were to bury him we wouldn't be able to do it according to his customs because we don't know what they were."

So the Iceman will remain the star museum exhibit for the thousands of people who come each year to the Alpine town and stare at his sticky, brown corpse.

But even if they can't bury him, today's distant relatives of the Iceman, might conceivably see the medical benefits -- if, as they say, his captors manage to unlock the secret of his genes.

Treasures of the mummies

Juanita (or the Ice Maiden)

Believed to have been between 12 and 14 years old when ritually sacrificed over 500 years ago, the well-preserved frozen corpse of Incan girl 'Juanita', above, was discovered by a US anthropologist and his guide 22,000 feet above sea level on Mount Ampato in southern Peru in 1995. The treasures of her tomb remained undisturbed, offering insight into the ceremony of Incan sacrifice.

The Tollund Man

Discovered in 1950 in a peat bog in Jutland, Denmark, the head of the 1,500 year-old 'Tollund Man' was so intact that he was initially mistaken for a recent murder victim. Deep wounds and a rope around his neck suggest he was hanged, a fate which usually befalls criminals. However, the careful arrangement of his corpse suggests he too was sacrificed.

The Lady of Dai

In 1971, diggers near Changsha, China, accidentally struck the 2,000-year-old tomb of Xin Zhui, Lady of the Dai region and wife of the Marquis of Han. Around 50-years-old when she died, she was buried with 22, tightly wrapped, silk dresses. A mysterious red liquid preserved her corpse so well, her last meal was found in her stomach and blood (type A) was still in her veins. Scientists have identified medical problems linked to her rich diet.

King Tutankhamun

The most famous mummified pharaoh, Tutankhamun, above, became king in 1333 BC and died nine years later after a leg fracture led to complications. Known to be sickly, he died at the age of 19 during the 18th dynasty. His tomb was discovered in 1922 in the Valley of the Kings and his elaborate death mask has since become a symbol of ancient Egypt.

Rosalia Lombardo

Born in 1918 in Palermo, Sicily, Rosalia died of pneumonia aged two. Her distraught father commissioned a taxidermist to embalm her body. One of the last corpses to be placed in the Capuchin catacombs, her peaceful expression has earned her the nickname 'sleeping beauty'. The composition of such a successful embalming formula remained a mystery until recently, when it was discovered to be a mix of formalin, zinc salts, alcohol, salicylic acid, and glycerin.

Enjoli Liston

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