May 31, 2013

Ambitious Cloning Projects

A Siberian expedition found a well-preserved woolly mammoth. When scientists investigated, blood came running out.
 The mammoth-rebuilding project is
improved by a recent discovery of the Russian scientists, who uncovered a fairly fresh new mammoth.
A paleontological expedition team from the Research Institute of Applied Ecology of the North, North-Eastern Federal University, and the Russian Geographical Society went  to the  Novosibirsk archipelago in Siberia. There, the researchers discovered a female mammoth in a remarkable  state of preservation.
"The fragments of muscle tissues, which we've found out of the body, have a natural red color of fresh meat," declared the expedition leader Semyon Grigoriev. "The reason for such preservation is that the lower part of the body was underlying in pure ice, and the upper part was found in the middle of tundra", he added.

The scientists gathered blood samples to get the first tests.  "The blood is very dark, it was found in ice cavities bellow the belly and when we broke these cavities with a poll pick, the blood came running out," Grigoriev declared.

Australian scientists broke new ground in embryonic cloning by reviving a dead frog species. They used eggs from a distant cousin.
The Rheobatrachus silus frogs have been extinct since 1983. This  Australian kind of creatures used to swallow  the own eggs and then to release the young from the mouth.
During five years , the Australian researchers have  conducted their experiments using somatic-cell nuclear transfer, a technique for creating a cloned embryo called the Lazarus Project. They took donor eggs from a related frog to replace those nuclei with dead nuclei from the extinct frog. Some of the eggs then started to grow.
. The embryos didn't make it past a few days, but they  gave the scientists a fresh cache of living cells for future cloning experiments.
"We are watching Lazarus arise from the dead, step by exciting step," declared the leader of the Lazarus Project team, Professor Mike Archer of the University of New South Wales in Sydney. The scientists from the University of Newcastle are  participating in this project, too.
The extinct frog's cell nuclei being gathered from tissues collected in the 1970s have been kept in a deep freeze until now.
 "We're increasingly confident that the hurdles ahead are technological and not biological and that we will succeed. Importantly, we've demonstrated already the great promise this technology has as a conservation tool when hundreds of the world's amphibian species are in catastrophic decline," Archer declared.

The scientists in New Zealand found that DNA decays far quicker than previously considered, making be impossible to salvage the usable genetic material belonging to the dead dinosaurs.

The DNA fact-finding project involved a team of palaeogeneticists. They tested 158 leg bones belonging to three species of the extinct giant moa birds ranging from 600 to 8,000 years old.
After running many comparisons between the age of the various bones and DNA degradation within each specimen, the scientists estimated that DNA's half-life works out to about 521 years after being kept in a swamp with an average temperature of 13.1 Celsius (55 Fahrenheit). Even a more ideal preservation temperature of minus 5 Celsius (23 Fahrenheit) would only result in readable DNA from specimens up to 1.5 million years old, meaning there is no possible way we can see a 65-million-year-old T-Rex waving its tiny arms about in this time frame.

DNA breaks down for a variety of reasons, including degradation from external influences such as temperature, water, soil chemistry, and so on. After half a millennium, the researchers assume that DNA continues to degrade as the nucleotide bonds within break in half. Each 521-year segment serves as another chapter of nucleotide structure breakdown and carries on until the bonds no longer exist. However, science has yet to determine the breakdown speed of DNA in environments that are more supportive of preservation, such as permafrost.
Morten Allentoft at the University of Copenhagen and Michael Bunce at Murdoch University in Perth, Australia, worked with a large team on the findings, which were published today in the Proceedings of the Royal Society B science journal.

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