18 January 2011

The dream of a cloned mammoth: details

Pleistocene Park
Japanese scientist is ready to recreate mammoths
Evgeny Paperny, Tape.Roo

It took humanity a little more than a hundred years to realize the flight to the moon described by Jules Verne in 1865. "Jurassic Park", invented by science fiction writer Michael Crichton in a 1990 book, may become a reality three decades later.

Japanese researcher Akira Iritani is preparing to make another breakthrough in scientific progress. Now Mr. Iritani is 80 years old. The rebirth of the mammoth may be the crowning achievement of this scientist's career. At one time, he became famous for "crossing" a pig with spinach (in fact, we are talking, of course, about transferring only one gene), creating animals whose fat is less dangerous for the health of the cardiovascular system. Iritani has been persistently engaged in the embodiment of the idea of the mammoth revival for the third decade. The Mammoth Creation Society, of which Iritani is one of the leaders, announced plans to recreate shaggy elephants back in the mid-nineties.

Mammoths, which surpassed the size and mass of modern elephants, became extinct about 10 thousand years ago, although a separate small variety of them lived on Wrangel Island until the II millennium BC (when, for example, the Egyptian pyramids were already built). Most of the known mammoth remains have been preserved in permafrost in Eastern Siberia. In 2008, the mammoth genome was fully read. Unfortunately, knowing the exact sequence of "letters" in its genetic code and having viable animal DNA at our disposal is not the same thing.

TechnologyIn 1996, the first attempts to find a suitable biological material began – in cooperation with Russian specialists in the vicinity of Yakutsk, Iritani began searching for a sample of frozen animal sperm.

Unfortunately, in order for sperm to retain fertility (the ability to fertilize), a completely extreme combination of temperature conditions is required. There was even less hope of finding properly frozen eggs.

Therefore, scientists had to follow a more complex path, which was successfully implemented for the first time (for warm-blooded animals that exist today) in 1996. Then the Scottish Roslin Institute cloned the famous Dolly lamb. To do this, you only need the nucleus of an ordinary, non-sexual, cell containing genetic material. Such a nucleus is injected into a previously nucleoless egg cell of another organism and the resulting egg is planted for gestation in the uterus of a surrogate mother. In the case of mammoths, it is assumed that an elephant will be able to bear the fetus, and therefore a third group of scientists from Thailand joined the team of researchers.

Unfortunately, DNA that has been frozen for a long time is almost always damaged. We are talking about the mechanical effect of ice crystals, and about the minimal but persistent activity of enzymes, although minimal at low temperatures, but sufficient to destroy chromosomes over ten millennia separating the death of the "mother" animal from us in the Pleistocene period.

The technique, which, apparently, can bring success to paleontologists, was tested several years ago by the Japanese researcher Teruhiko Wakayama. Its essence is in the preliminary cultivation of several stem cell lines, from which the nucleus is subsequently taken to be transplanted into a nuclear–free egg of a donor elephant. Using this technology, Wakayama managed to "recreate" a mouse with the help of genetic material obtained from an animal that had been in the freezer for 16 years.

The tasks that have yet to be solved are how to grow a cloned creature using an egg of an individual of another species. The fact is that mitochondria, which have their own genetic apparatus, are responsible for energy production in animal cells. The hereditary information in the mitochondria of mammoths differs from that in the mitochondria of elephants, that is, these organelles themselves are slightly different. It is unclear whether it will be possible to grow a healthy mammoth with elephant mitochondria, and scientists have not yet begun to solve the problem of recreating fossil mitochondria.

In addition, it is unclear how the pregnancy of an elephant with a mammoth baby will proceed and how to feed it later. Alas, miscarriages and "frozen pregnancy" are not uncommon in animals, even when carrying their own offspring.

Nevertheless, it was announced for the first time that scientists are not just close to understanding the way to solve the problem, but intend to proceed directly to its implementation.

"I'm here, I've arrived"However, one should not think that when mammoths are revived, they will be paraded through the streets of our cities.

According to Iritani himself, the mammoths that were born will live in a Pleistocene Park in Siberia. The approach of the Japanese scientist is so fundamental that eight years ago he flew around the site of the proposed mammoth nursery by helicopter and made sure that the grass on the pasture is juicy enough for animals and that people do not live there and have never lived there.

Experiments are already underway in Yakutia on the reintroduction (that is, re-settlement) of bison, musk oxen, wild horses (by crossing Przewalski's horses with Yakut horses). These animals (together with the dung beetle, also extinct in Yakutia and extremely important for the functioning of the Pleistocene ecosystem) will restore the flora of the current tundra, turning it into a so-called tundra covered with high-yielding meadows.

In the Far North, the grass grows well, but it rots badly. Nutrients do not return to the soil. In the presence of large herbivorous animals, plants will become manure, that is, an excellent fertilizer. According to the head of one of the reintroduction projects Sergey Zimov, it is enough to build a strong fence so that the animals do not run away, and things will immediately get better – the concentration of manure will be sufficient. Well, they understand the construction of fences in Siberia.

The closest relative of the mammoth tundra is the African savanna. Both there and there, the period of the flora's rampage is small, only a few months, and the rest of the time extreme weather conditions continue, whether it's heat with drought or frost with snowfall.

In terms of area, the Iritani nursery, as some Western media reports say, will double the territory of Japan. It is planned to build various buildings for tourists there, as well as shelters for the mammoths themselves, because the climate has become much more severe since they lived on Siberian land.

Harsh, however, does not mean colder in general. According to Iritani, one of the goals of his work is to draw public attention to the process of global warming. After all, it is for this reason that the remains of giant animals preserved for ten thousand years in captivity by permafrost appear on the surface of the earth and become a source of genetic material for the next wonders of civilization.

Portal "Eternal youth" http://vechnayamolodost.ru
18.01.2011

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