Clonabile il Mammut lanoso?

Arctic expedition finds 

woolly mammoth remains 

ripe for cloning 

Breakingnews, Early Mammals, Fossils, Genetics, Palaeontology, Russia 


Russian scientists undertaking an exploratory expedition on the Lyakhovsky Islands have discovered woolly mammoth remains including skin and tusk, which they believe suitable for obtaining the DNA necessary to clone the animal. 

The mammoth expedition led by scientists from Russia's North-Eastern Federal  University in Yakutsk, and funded by the Russian Geographical Society  

[Credit: ©: gazetayakutia.ru] 

An international expedition to the Lyakhovsky Islands led by scientists from Russia's North-Eastern Federal University in Yakutsk has discovered six specimens of woolly 
mammoth fossils suitable for extracting DNA.

"The Lyakhovsky Islands are considered the mammoth continent," explained Semyon Grigorev, leader of the expedition to the islands and director of the Mammoth Museum at Russia's North-Eastern Federal University in Yakutsk. "The largest concentration of remains in the world is here, so that's why we chose this area to carry out our studies," Grigorev told a press conference on Wednesday.
 "To start with, together with archeologists we carried out a dig at the most northern site where ancient man lived, not far from the village of Kazachye where we found an enormous amount of mammoth bones, and also ancient tools," said Grigorev of the expedition, which took place over two stages from August 11 to September 29. 

The discovery is seen as highly significant by Russian and South Korean experts  working to bring the mammoths back to life through cloning 

[Credit: NVK]

"Then, after waiting a long time for the right weather conditions, we continued to the main target of our expedition, Great Lyakhovsky Island, where we found a great amount of unique remains," which includes ancient mammoth skin and teeth. 
"Take, for example, the tusk of a pygmy mammoth that we found. We calculate that the animal was no more than two meters tall, so now we have to work out what this was – a micropopulation, or the peculiarity of this single individual." 
"Skin is the most interesting for us, for our project 'The Mammoth Rebirth' because our Korean colleagues consider skin to be the best material for an attempt at cloning via the extraction of viable cells."
 The 'Northern Ecumene' expedition of 16 researchers from six different countries was made possible thanks to a grant of two million rubles provided by the Russian Geographical Society. 
"We consider the expedition a success; after all, out of what seems to be these kinds of small expeditions, great scientific discoveries can be made," said Grigorev, whose team is now joining forces with Korean researchers to analyze the mammoth remains for cells viable for cloning. 

Source: Sputnik News [October 09, 2015]

Separare DNA antico dal nuovo

E' noto che tutto il materiale fossile scoperto prima che esistesse la tecnica di studio del DNA è stato 'contaminato' con DNA moderno, perché gli archeologi lo maneggiavano a mani nude, lasciando inconsapevolmente tracce di DNA moderno sui reperti.
Questo fatto produsse alcuni risultati comico-grotteschi, quando si iniziò lo studio biomolecolare del DNA (creduto antico), trovando 'sensazionali ed inaspettate' somiglianze interspecifiche (S. Paabo et al.) che poi - naturalmente - furono smentite con studi più corretti.
Oggi è stato proposto un metodo che 'apre le porte' allo studio del materiale fossile contaminato da DNA moderno, semplicemente separando il DNA sulla base delle alterazioni cui esso va incontro nel tempo e permettendo la distinzione tra antico (che si intende esaminare) e moderno (inquinante, che si deve scartare).
Questo semplice procedimento renderà disponibile un'enorme quantità di materiale che fino ad oggi giace nei depositi inutilizzato.

mtDNA of Okladnikov Neandertal

PNAS February 11, 2014 vol. 111 no. 6 

Separating endogenous ancient DNA from modern day contamination in a Siberian Neandertal 

Pontus Skoglund et al.

One of the main impediments for obtaining DNA sequences from ancient human skeletons is

 the presence of contaminating modern human DNA molecules in many fossil samples 

and laboratory reagents.

 However, DNA fragments isolated from ancient specimens show a characteristic DNA damage pattern 

caused by miscoding lesions that differs from present day DNA sequences. 

Here, we develop a framework for evaluating the likelihood of a sequence originating from a model 

with postmortem degradation—summarized in a postmortem degradation score—which allows

 the identification of DNA fragments that are unlikely to originate from present day sources.

 We apply this approach to a contaminated Neandertal specimen from Okladnikov Cave in Siberia 

to isolate its endogenous DNA from modern human contaminants and show that

 the reconstructed mitochondrial genome sequence is more closely related to the variation of Western Neandertals than what was discernible from previous analyses. 

Our method opens up the potential for genomic analysis of contaminated fossil material. 

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