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Thread: Mammoet uit die Graf

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    Default Mammoet uit die Graf

    Navorsers kan mammoet uit graf bring

    2011-02-12 16:00

    Japanse navorsers gaan vanjaar ’n projek begin om die eerste keer ’n mammoet te teel.

    Hulle wil dié harige olifantspesie, millennia gelede reeds uitgestorwe, binne die volgende vyf jaar uit die graf terugbring.

    Met ’n tegniek wat baie aan die rolprent Jurassic Park herinner, wil hulle weefsel uit die karkas van ’n mammoet wat in ’n Russiese laboratorium bewaar word, haal en dit dan kloon.

    “Ons is klaar besig met die voorbereidings,” het prof. Akira Iritani, hoofnavorser en professor aan die Universiteit van Kioto, aan die dagblad Jomioeri Sjimboen gesê.

    Volgens dié plan sal die mammoet-selkern geplaas word in ’n olifant se eiersel waarvan die kern verwyder is om só ’n embrio met mammoetgene te skep.

    Die embrio sal dan in die baarmoeder van ’n olifant geplaas word in die hoop dat dié dier uiteindelik ’n mammoet in die lewe sal bring.

    Die olifant is die naaste moderne familielid van die mammoet, ’n enorme wollerige soogdier wat vermoedelik in die vorige Ystydperk uitgesterf het.

    Sommige mammoet oorblyfsels het nog behoue weefsel, wat dit moontlik maak om selle daaruit te haal (anders as dinosourusse, wat 65miljoen jaar gelede uitgesterf het en waarvan slegs fossiele agtergelaat is).

    Benewens die Japanse navorsers is ook ’n Russiese mammoet-kenner en twee Amerikaanse olifantkenners deel van die projek.

    Hulle het reeds ’n metode gevind om DNS uit bevrore selle te verkry, iets wat voorheen onmoontlik was weens die skade wat selle opdoen wanneer weefsel vries.

    ’n Ander Japanse navorser, dr. Teroehiko Wakajama van die Riken-sentrum vir ontwikkelingsbiologie, het in 2008 daarin geslaag om ’n muis te kloon met selle van ’n ander muis wat 16 jaar lank in toestande soortgelyk aan bevrore grond gehou is.

    Iritani se span gaan nou dié tegniek inspan.

    “Voordat ons dit kloon, moet ons egter net besluit wat ons met die mammoet gaan doen en of ons dit in die openbaar gaan ten toon stel,” sê Iritani.

    Meer as 80% van die mammoet-oorblyfsels wat al gevind is, is in die Sakha-republiek in die ooste van Siberië opgegrawe.

    Daar word wyd gedebatteer oor presies hoekom dié enorme diere, wat in die vorige Ystydperk in groot troppe oor die vlaktes van Eurasië en Noord-Amerika geswerf het, uitgesterf het.

    Sommige kenners meen hulle is deur mense tot uitwissing gejag. Ander meen hulle was slagoffers van klimaatsverandering en dat hulle nie by ’n wêreld kon aanpas wat vinnig besig was om warm te word nie. – AFP

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    Default Re: Mammoet uit die Graf

    Woolly mammoths: Japanese scientists take ‘significant step’ towards bringing prehistoric giants back to life

    Cells extracted from carcass of frozen mammoth injected into mouse tissues


    Wooly-Mammoths-1.jpg
    ‘Significant steps’ have been made towards
    bringing the extinct species back to life


    The last woolly mammoth populations died out just over 4,000 years ago, but the prehistoric giants could soon be back and plodding about just like they were during the ice age.

    Scientists in Japan claim to have taken a “significant step” towards bringing the extinct species back to life, after they transplanted cells extracted from the carcass of a mammoth into a mouse, where they subsequently recorded positive biological activity.

    The cells were taken from the 28,000-year-old mummified remains of a woolly mammoth, named Yuka, found in Siberian permafrost in 2010. The animal, which died when it was about seven-years-old, is one of the best preserved mammoths known to science.

    The team extracted tissue samples from the animal’s bone marrow and muscle, which they described as “well preserved”.

    They then began searching for cell nuclei remains. In total, 88 nucleus-like structures were collected from the muscle sample.


    The team said following the procedure a “pronucleus-like structure budded from the injected … mammoth nucleus”.

    They also found possible signs of repair to damaged mammoth DNA.
    “These results indicate that a part of mammoth nuclei possesses the potential for nuclear reconstitution,” the scientists said, in a paper published in the journal Nature.

    Despite the successes, the scientists did not observe the further cell division necessary to create a viable egg, “possibly due to the extensive DNA damage in the transferred nuclei”.

    This marks a “significant step toward bringing mammoths back from the dead”, researcher Kei Miyamoto, one of the study’s authors told Japan’s Nikkei news outlet.
    “We want to move our study forward to the stage of cell division,” he added, but acknowledged “we still have a long way to go”.

    Most mammoth populations died out between 14,000 and 10,000 years ago. The last mainland population existed in the Kyttyk peninsula of Siberia until 9,650 years ago.

    But the species survived for another 5,000 years on Siberian islands, which became cut off from the mainland by retreating ice following the last ice age.

    The last known population remained on Wrangel Island in the Arctic Ocean until 4,000 years ago – well beyond the dawn of human civilisation, but finally becoming extinct around the time of the construction of the pyramids of Giza in Egypt.

    There is no scientific consensus on the chief cause for the creatures’ demise, but climate change significantly reduced habitable parts of the globe for mammoths, and they were also hunted by humans.

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