Most of Woolly Mammoth Genome Reconstructed 245
geekmansworld writes "From the Washington Post, 'An international team of scientists has reconstructed more than three-quarters of the genome of the woolly mammoth using DNA extracted from balls of hair, the first time this has been accomplished for an extinct species.' Who wants a pet mammoth?"
Re:When did they die out? (Score:3, Informative)
My understanding is that the woolly mammoth is one of the first casualty of the infestation Earth by the human species : they went extinct partly because of the warming climate, partly because of overhunting.
Re:Not quite there yet (Score:1, Informative)
Not to mention... (Score:4, Informative)
Not to mention, didn't we also have this story about how the proteins affect the transcription too, and the same piece of DNA can be transcribed in a dozen different ways or not at all, depending on how those proteins regulate it? It seems to me like in that case it's like saying they decoded half of it.
Re:Just fill in the remaining genes (Score:3, Informative)
Um.... I thought they used frog DNA to fill-in the missing sequences. Which is how supposedly "sterile" dinosaurs were able to give birth.
Re:When did they die out? (Score:5, Informative)
Re:Not quite there yet (Score:5, Informative)
The mammoth mitochondrial genome was decoded a few years ago.
Mito DNA is much easier to sequence from old samples due to the fact that for every cell which contains one copy of the nuclear genome, there are thousands of copies of the mitochondrial genome.
Re:When did they die out? (Score:4, Informative)
They were quite recent: They survived on Wrangle Island (Artic) and St Paul Island (Bearing Sea) as dwarfs until 1700 BCE.
They were also found on the Channel Islands off California and disappeared around 40,000 BCE. They are still digging them up, preserved, in the permafrost of Siberia.
Humans did hunt mammoths, sabre-tooths etc.
Crocodiles!=dinos, and mammal coexisted w/ dinos (Score:4, Informative)
Crocodilians [wikipedia.org] do not come from dinosaurs, although they are related, i.e. their earliest common ancestor was neither a dinosaur nor a crocodilian. On the other hand, the earliest common ancestor of birds was a dinosaur.
Also, mammals existed at least 125Mya [wikipedia.org]:
The oldest known marsupial is Sinodelphys, found in 125M-year old early Cretaceous shale in China's northeastern Liaoning Province. The fossil is nearly complete and includes tufts of fur and imprints of soft tissues.
Re:Not quite there yet (Score:3, Informative)
Shouldn't something along the line of "we don't know whether they taste nice" be in there?
There have been some reports of Russians eating frozen Mammoth, but I'm not sure how true that is (I read it somewhere, but I can't remember where).
Here are some quick links I found on the topic:
link 1 [straightdope.com]
link 2 [stupidquestion.net]
Re:Not quite there yet (Score:3, Informative)
Re:Not to mention... (Score:5, Informative)
The folks at 454 Life Sciences made reconstructing a genome from lots of little pieces pretty simple by using an algorithm that looks for common fragments (ex AAGGCTTCTA and CTTCTATCTGG probably go together to form AAGGCTTCTATCTGG).
They also pretty much pioneered modern sequencing techniques.
The news here (IMHO) is that we've been able to read the genome of an extinct animal. That is an impressive achievement, a few BP errors notwithstanding. If we have multiple copies of the genome (multiple cells), we should be able to figure out what the correct sequence is (mutations are random, and no two cells will have the same mutations). Hair is not exactly the prime target for sequencing due to its exposure to UV light (UV light wreaks havoc on DNA), but with a little work we should be able to the actual sequence.
So at the end of the day, the Nobel prize goes to the guy who can figure out how many chromosomes a mammoth had. I'd like to say "just use the number that elephants have" but 7 million years (last common ancester) is easily enough time for chromosome duplication to occur.
Re:Crocodiles!=dinos, and mammal coexisted w/ dino (Score:4, Informative)
>Well the placental mammals, like us and almost every other mammal, did not evolve until after the Asteroid event.
Wrong. There were plenty of mammals in the Mesozoic. And according to the University of California Museum of Paleontology "Eutherians first became common in central Asia during the Upper Cretaceous." Eutherians being the technically correct name for placental mammals.
http://www.ucmp.berkeley.edu/mammal/eutheria/eutheriafr.html [berkeley.edu]
Re:When did they die out? (Score:3, Informative)
Repenomamus was a Triconodont, which is its own category, not a modern marsupial or placental.
Re:Not to mention... (Score:5, Informative)
The folks at 454 Life Sciences made reconstructing a genome from lots of little pieces pretty simple by using an algorithm that looks for common fragments (ex AAGGCTTCTA and CTTCTATCTGG probably go together to form AAGGCTTCTATCTGG).
Spoken like one who has never actually tried to assemble a genome sequence. Trust me, there is absolutely nothing simple about it. And while 454 Life Sciences (now a division of Roche Diagnostics) pioneered a new technology for generating raw DNA sequence data they did not pioneer the assembly process. Sequence assembly algorithms are a long and well studied problem.
They also pretty much pioneered modern sequencing techniques.
While 454 was first to the market with a next-generation sequencing platform they are currently in heavy competition with the Illumina/Solexa platform. And then there is Pacific Bioscience due to release a platform in 2010 which could eat both their lunches.
Re:Just fill in the remaining genes (Score:5, Informative)
the tasmanian devil is still alive and well
I don't think "well" is the right word [sciencedaily.com] to describe the Tasmanian devil's status.
Acfually, there isn't (Score:3, Informative)
Actually, apparently there is exactly 0% Neanderthal in us, if you look at the DNA. You can see the differences between Neanderthals and the common ancestor (since that's what made them Neanderthals), and you can see the differences between humans and the common ancestor (since that's what makes us humans.) The two sets just don't overlap. All the genes that made Neanderthals be Neanderthals are not present in us.
The easiest to look at is the mitochondrial DNA, since it's pretty small, and it's been mapped to death for both species. We just don't have any humans which show the unique Neanderthal mutations there. So at least there was no _female_ neanderthal in anyone's ancestry.
Now I'd be surprised if they didn't at least try to have sex with each other, given that in some places they lived in the same cave for tens of thousands of years. I mean, so it was short and stout women with sloped foreheads. Some people would still try to screw one, if one was available. And viceversa.
The more probable explanation is that, like any other combination of different species, the offspring was either non-viable (if the species are not that related) or sterile (if they're closely related.) E.g., see mules, or either combination of lion and tiger.
Re:Not to mention... (Score:3, Informative)
Well, kmcarr, I bow before your expertise. I've never sequenced a genome, let alone the type of massively parallel sequencing you've done (you're the guy that worked on Arabidopsis sequencing, right?)
In my defense, however, I only said that 454 had made life a lot easier for people doing sequencing, not that the algorithm itself was simple. I also note that you yourself used their pyrophosphate technique - to say that it's anything but a huge technological leap forward is to undercredit it. I repeat, 454 pioneered the sequencing techniques we use today.
Wish you'd post more often to Slashdot, we could do with more biology types around here.