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Author Topic:   Question for Mammuthus
Quetzal
Member (Idle past 4334 days)
Posts: 3228
Joined: 01-09-2002


Message 1 of 7 (15831)
08-21-2002 9:45 AM


In some thread, you indicated that to date the DNA that has been recovered from mammoths is only bits and pieces. IOW, there wasn't enough to sequence anything resembling a full genome. CNN (a major source of misinformation to start with) has an article today about some group of Japanese scientists who plan on starting a "Jurassic Park" type of "cloning" experiment using recovered DNA and an African elephant (as host mother, apparently). Here's the link. Is this typical journalist over-enthusiasm, speculation, or even remotely legit? In 50 years, with what has been recovered to date, can they really recreate a critter "88%" (odd figure, that) mammoth? Or are they talking out their collective cloaca?

Replies to this message:
 Message 2 by Mammuthus, posted 08-26-2002 6:02 AM Quetzal has responded

  
Mammuthus
Member (Idle past 4937 days)
Posts: 3085
From: Munich, Germany
Joined: 08-09-2002


Message 2 of 7 (16067)
08-26-2002 6:02 AM
Reply to: Message 1 by Quetzal
08-21-2002 9:45 AM


Hi Quetzal
I would have to go with the "collective cloaca". CNN is a fountain of misinformation (or at least poor presentation) and their science reporting is horrid. I did see the article and have to assume that it is the same Japanese group that has made this claim in the past. Susumu Goto was a fertility specialist in the dairy industry in Japan as I recall and his claim is that since he under controlled lab conditions could freeze bull sperm and later use it to successfully fertilize cow eggs in vitro, that mammoths could be cloned. This ignores several relevant facts. First, the cow experiments were done under highly controlled lab conditions designed to prevent the sperm from degrading during freezing and thawing. Second, the tissues from which the sperm derived had not rotted. Third, the freezing temperature was stable.

Mammoth samples were not frozen under controlled conditions. An animal as large as a mammoth when it dies will take a very long time to freeze allowing for necrophilic bacteria and fungi to consume large parts of the animal (including DNA). DNA in post mortem tissues is subject to hydrolysis and oxidative damage that DNA repair mechanisms no longer fix for obvious reasons. Also, permafrost is not like a freezer. The temperature can vary and large portions can freeze and thaw repeatedly...let's see them clone a cow from a 10 year old piece of freezer burned steak much less a 50,000 year old freezer burned mammoth meat!

My own experience with mammoth material, including very well perserved samples with flesh attached to the bones demonstrates that only fragments as long as about 200 bp can be retrieved for nuclear DNA...about double this for mitochondrial DNA but you won't clone anything with mtDNA. The proteins are also in horrible shape with tremendous amounts of cross linking and degredation down to single amino acids for the most part. A study from the 80's also showed that many essential elements were at concentrations much lower than normal for living tissues most importantly phosphorous was at about 0.1%. This sucks for large scale DNA retrieval.

However, the concept of cloning mammoths really grabs peoples attention so this exact same type of article pops up at least once every year and has done so since Dolly was cloned. I loved in that article how they mentioned the park in Siberia where musk ox have been transferred as if this is a testament to cloning success! Musk ox are not extinct! They flew the darn things in from Alaska...unless cloning is being defined as flying heavy mammals in FedEx planes by the media, this hardly justifies opening a Pleistocene Park.

There is another extinct animal cloning project in Australia where they say they will clone the Tasmanian wolf. The CNN report announced as a major breakthrough that they had obtained DNA strands (believe mtDNA) and that this was the beginning they needed. Well, in about 1992 Alan Cooper published DNA sequences from this species so it is not such a novelty. In addition, when has anything ever been cloned from a simple fragment of DNA?

Personally I wish they (they being CNN and several of the other news outlets) would refrain from doing the yearly extinct animal cloning story since it makes any serious research on the subject look really flaky. If they actually do nuclear transfer and get cell division then that would warrant a story. But otherwise they might as well talk about cloning Elvis from a potato.

There is a book called Mammoth: The resurrection of an Ice Age giant by Richard Stone that came out last year that does a very thorough job discussing this very issue with a more heavy focus on why mammoth went extinct in the first place.

Sorry for such a long (mammoth) post

Ciao,
Mammuthus

quote:
Originally posted by Quetzal:
In some thread, you indicated that to date the DNA that has been recovered from mammoths is only bits and pieces. IOW, there wasn't enough to sequence anything resembling a full genome. CNN (a major source of misinformation to start with) has an article today about some group of Japanese scientists who plan on starting a "Jurassic Park" type of "cloning" experiment using recovered DNA and an African elephant (as host mother, apparently). Here's the link. Is this typical journalist over-enthusiasm, speculation, or even remotely legit? In 50 years, with what has been recovered to date, can they really recreate a critter "88%" (odd figure, that) mammoth? Or are they talking out their collective cloaca?

This message is a reply to:
 Message 1 by Quetzal, posted 08-21-2002 9:45 AM Quetzal has responded

Replies to this message:
 Message 3 by Quetzal, posted 08-26-2002 6:18 AM Mammuthus has responded

  
Quetzal
Member (Idle past 4334 days)
Posts: 3228
Joined: 01-09-2002


Message 3 of 7 (16068)
08-26-2002 6:18 AM
Reply to: Message 2 by Mammuthus
08-26-2002 6:02 AM


Thanks for your post M. I figured it was something like that. I don't generally get my science from CNN , but someone forwarded the link and I thought I'd take shameless advantage of your expertise. Much appreciate your response.

This message is a reply to:
 Message 2 by Mammuthus, posted 08-26-2002 6:02 AM Mammuthus has responded

Replies to this message:
 Message 4 by Mammuthus, posted 08-26-2002 11:44 AM Quetzal has not yet responded

  
Mammuthus
Member (Idle past 4937 days)
Posts: 3085
From: Munich, Germany
Joined: 08-09-2002


Message 4 of 7 (16074)
08-26-2002 11:44 AM
Reply to: Message 3 by Quetzal
08-26-2002 6:18 AM


Hi Quetzal,
Any time. I'm always happy to talk about mammoths. Living in Germany I try to update myself on the U.S. but not from CNN...but I do take a peek once in a while at what they are promoting..oops I mean reporting

ciao,
Mammuthus

quote:
Originally posted by Quetzal:
Thanks for your post M. I figured it was something like that. I don't generally get my science from CNN , but someone forwarded the link and I thought I'd take shameless advantage of your expertise. Much appreciate your response.

This message is a reply to:
 Message 3 by Quetzal, posted 08-26-2002 6:18 AM Quetzal has not yet responded

  
Tranquility Base
Inactive Member


Message 5 of 7 (16079)
08-26-2002 7:11 PM


I read somewhere reasonably respectable that the mammoth project was going to proceed via artificial insemination of elephants using mammoth sperm. They are looking for the mammoths testes. The hope is to end up with something 88% mammoth after several generaitons in about 50 years time.

It is not a cloning project. The freezing issue is of course an important one and we'll just have to wait and see. All they need is one undamaged sperm. And you don't have to find it biotechnologically. The elephant egg will find it for you! Given that other tissues have survived I would give this project a chance.

I think this comes under the heading of 'why not try'.

[This message has been edited by Tranquility Base, 08-26-2002]


Replies to this message:
 Message 6 by Quetzal, posted 08-27-2002 3:30 AM Tranquility Base has not yet responded
 Message 7 by Mammuthus, posted 08-27-2002 4:34 AM Tranquility Base has not yet responded

  
Quetzal
Member (Idle past 4334 days)
Posts: 3228
Joined: 01-09-2002


Message 6 of 7 (16097)
08-27-2002 3:30 AM
Reply to: Message 5 by Tranquility Base
08-26-2002 7:11 PM


Uhh, TB? That's precisely the report M and I were discussing. Re-read his response (post #2).

This message is a reply to:
 Message 5 by Tranquility Base, posted 08-26-2002 7:11 PM Tranquility Base has not yet responded

  
Mammuthus
Member (Idle past 4937 days)
Posts: 3085
From: Munich, Germany
Joined: 08-09-2002


Message 7 of 7 (16099)
08-27-2002 4:34 AM
Reply to: Message 5 by Tranquility Base
08-26-2002 7:11 PM


Greetings Tranquility Base,
I would argue that CNN science reporting is not respectable
But nonetheless, you are correct about it not being exclusively a cloning project. Goto would like to either find sperm or eggs from mammoths and try to cross breed mammoth and modern elephants. He has also proposed trying nuclear transfer and cloning a 100% mammoth...well not 100% if it is sperm since all the mitochondria would come from the elephant.

There is an issue beyond just the DNA damage, freezing and thawing, and the fact that I and others have never obtained more than a few 100 bp of intact DNA from any tissues of dozens of mammoths (not to mention any other old or ancient sample from any species). There is no reason to believe that an elephant/mammoth hybrid would be viable. Asian and African elephants are two separate genera that do not produce offspring when crossed. Mammuthus primigenius was almost equidistant genetically from both. There was one live birth of an African/Asian hybrid elephant which died after 10 days. It is not known if it was fertile as most F1 hybrids are not. So even if you had a living mammoth in your back yard a cross with an elephant would likely fail.

I would add to your heading of "why not try"..."with private funds that do not detract from serious research"...it seems that Goto and company have these funds to flush.

Cheers,
Mammuthus

quote:
Originally posted by Tranquility Base:
I read somewhere reasonably respectable that the mammoth project was going to proceed via artificial insemination of elephants using mammoth sperm. They are looking for the mammoths testes. The hope is to end up with something 88% mammoth after several generations in about 50 years time.

It is not a cloning project. The freezing issue is of course an important one and we'll just have to wait and see. All they need is one undamaged sperm. And you don't have to find it biotechnologically. The elephant egg will find it for you! Given that other tissues have survived I would give this project a chance.

I think this comes under the heading of 'why not try'.

[This message has been edited by Tranquility Base, 08-26-2002]



This message is a reply to:
 Message 5 by Tranquility Base, posted 08-26-2002 7:11 PM Tranquility Base has not yet responded

  
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