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Author Topic: New Woolly Mammoth Found With Blood - Will It Happen?  (Read 3209 times)

Offline Super Hans

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Does this discovery make it any more likely that they will be able to clone these beasts? I know there have been difficulties in the past, but it seems they have access to blood in which I assume lie intact cells.

Not really interested in the moral side of it, I'm just asking, does this discovery make it any more possible, or is it just another "We're gonna clone a mammoth!" story that never actually comes into fruition?

http://www.cbsnews.com/8301-205_162-57586854/woolly-mammoth-containing-liquid-blood-discovered-in-russia/ [nofollow]

http://www.independent.co.uk/news/science/mammoth-discovery-jurassic-park-takes-a-step-closer-to-reality-as-russian-scientists-find-blood-in-woolly-mammoth-8637871.html [nofollow]



 

Offline CliffordK

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Re: New Woolly Mammoth Found With Blood - Will It Happen?
« Reply #1 on: 30/05/2013 19:27:01 »
Red blood cells actually do not have a nucleus, and thus are a very poor source of DNA.  White blood cells, however, do have a nucleus and DNA. 

Anyway, DNA can be recovered from any tissue including muscle, and perhaps even bone, not just blood.

The advantage of this specimen is that it may be better preserved than other Mammoth specimens which would be a great benefit for DNA and perhaps chromosome recovery. 

It sounds like the Mammoth may have a cryoprotectant in the blood which is very interesting.  Do reindeer and caribou have similar cryoprotectants?  It is possible, however, that whatever is keeping the blood from fully freezing has become concentrated over time.
 

Online evan_au

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Re: New Woolly Mammoth Found With Blood - Will It Happen?
« Reply #2 on: 01/06/2013 09:51:08 »
There have been many mammoths discovered which are frozen solid after a variety of mishaps in a snowy landscape.
  • Some of these were still encased in ice and snow.
  • A large, well-insulated mammoth body takes a while to cool down, which increases the chance of bacterial growth and DNA degradation.
  • As ice crystallises, it tends to form needle-like crystals which grow through the cell, puncturing cell walls and internal organelles (including the nucleus and its DNA).
  • As the body of water freezes, it expands, bursting cell membranes.

However, a different process appears to have taken place here.
  • For one thing, the snow had melted away, and the mammoth body was exposed at the surface
  • Animals had picked at it
  • This means that bacteria would have had access to the body, at a temperature close to liquid water
  • So unless they actually find intact white blood cells in this "blood", I would guess that this "blood" is actually a bacterial "mammoth stew"
It's a matter of time before someone succeeds in getting a usable sample of mammoth DNA for sequencing
  • It is then an effort to decode the DNA fragments and stitch them together.
  • One of the early DNA sequencing techniques called "shotgun sequencing" actually starts by chopping up the DNA into small pieces and sequencing each piece. They pieces are then stitched together by computer.
  • The stitched-together DNA could (one day) be "printed" by a computer (previously, viable bacterial DNA has been successfully printed by a computer).
 

Offline Super Hans

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Re: New Woolly Mammoth Found With Blood - Will It Happen?
« Reply #3 on: 02/06/2013 01:39:26 »
In laymans terms, what exactly do we mean by DNA sequencing and why is it necessary to bring the Mammoth back to life?

Thanks.
 

Offline cheryl j

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Re: New Woolly Mammoth Found With Blood - Will It Happen?
« Reply #4 on: 02/06/2013 04:04:18 »

  • This means that bacteria would have had access to the body, at a temperature close to liquid water
  • So unless they actually find intact white blood cells in this "blood", I would guess that this "blood" is actually a bacterial "mammoth stew"

What if the blood they were referring to was bone marrow? That might be more protected.
 

Online evan_au

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Re: New Woolly Mammoth Found With Blood - Will It Happen?
« Reply #5 on: 02/06/2013 05:40:29 »
Cheryl, the video showed a black liquid which had pooled underneath the mammoth body. So it doesn't sound like the contents of bone marrow?

Hans: The easiest way to protect an endangered species or to bring an extinct species back to life is to not let it go extinct in the first place! Some efforts to preserve endangered bird species are costing $US100,000 per chick.

Since preservation is no longer an option for mammoths, there are several much more difficult techniques which have been demonstrated to some extent, and that might be usable, one day:
  • In-vitro fertilisation, and implantation in a closely-related species. This relies on availability of viable eggs & sperm (doubtful) and availability of a closely related host (the Asian elephant?). Has been used with some endangered species. But frozen mammoth eggs and sperm are shattered by the freezing process.
  • Extracting the nucleus from the body cell of a mammoth, and inserting it in the egg cell of a very closely related species (an elephant?) to clone it. This relies on having a body cell with intact DNA (doubtful), and the compatibility with the host egg cell (unknown). This method succeeded with Dolly the sheep, but even then it had a success rate of <0.5% with fresh body cells and the same species as a host. Frozen mammoth DNA is shattered by the freezing process, breaking the chromosomes into short segments which cannot divide. This method as currently demonstrated would at best produce a mammoth with elephant mitochondria.
  • Reading the pieces of DNA in a DNA sequencer, and "stitching" them together in a computer. Then "printing out" this DNA and inserting it into a host egg cell. DNA sequencer technology is advancing at an amazing rate - this year's machines are many times faster than last year's machines. However, you need DNA which has been kept cool and away from sunlight and moisture, and has not been attacked by bacteria or chemicals. While mammoth DNA has been mostly sequenced (some repetitive regions prove difficult), printing DNA is at a much more primitive stage of development.
The key measure for measuring the quality of preserved DNA is the average fragment length. Humans have about 3 billion base pairs of DNA, spread over 23 chromosomes (we have 2 copies of each chromosome). Intact DNA has DNA lengths of 250 million base pairs. Stored in less-than-ideal conditions, this rapidly breaks down to fragments of perhaps 150 base pairs long (if it is not entirely digested by bacteria!) - this is a jigsaw puzzle of frightening proportions!

However, short of a mammoth drowning in a vat of liquid nitrogen or EDTA, having a mammoth rapidly frozen after falling into a crevasse is about the best preservation you could imagine.

Also see: http://www.aolnews.com/2011/01/18/can-woolly-mammoth-be-cloned-from-frozen-dna/
« Last Edit: 02/06/2013 05:42:02 by evan_au »
 

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Re: New Woolly Mammoth Found With Blood - Will It Happen?
« Reply #5 on: 02/06/2013 05:40:29 »

 

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