Comments on: Dinosaur proteins, cells and blood vessels recovered from Bracyhlophosaurus

By: Sigmund

Sigmund — Tue, 05 May 2009 18:23:13 +0000

I remember reading the first couple of papers on this matter and being particularly impressed with the antibody staining results rather than the mass spec data (it was the mass spec data that got all the initial attention – both overly favorably in the beginning and then overly negatively when the contamination/bacterial film hypothesis was suggested). They have really strengthened the antibody side of the work in this new paper. As for the question of how proteins can survive this length of time – (nucleic acids almost certainly cannot – they are much more suscepible to biological and chemical degradation and frequently have radiactive phosphorus present that causes further degradation) its certainly an interesting point. WHat I’ve heard about this matter is that certain conditions (high levels of stable protein like collagen in close proximity to mineralized bone matter) can provide remarkably stable conditions that result in the partial preservation of these proteins under the right circumstances.

By: Bob Davidson

Bob Davidson — Mon, 04 May 2009 15:37:02 +0000

I would like to see that soft tissue dated by every available means. There is no way it could have survived 80,000,000 years.

By: Nathan Myers

Nathan Myers — Sun, 03 May 2009 07:35:30 +0000

Sometimes what’s interesting in a story isn’t the main topic. The importance of collagens in tumor growth is new to me. Likewise, I had no idea that protein sequencing had been automated. It must make finding genes responsible for a protein much easier, though I doubt actually as easy as anyone hoped.

By: Dan J. Andrews

Dan J. Andrews — Sun, 03 May 2009 05:29:56 +0000

I’m stunned that they could recover anything after millions of years. Wow! First time I heard about it I thought there’d be an error. But the results have been duplicated, and done so in a more rigorous fashion. Wow again!
Ed, if you come across any explanations as to how it is possible that these tissues could last this long, please post it. I didn’t think tissues could last a few millenia let alone a few million years.

By: Lilian Nattel

Lilian Nattel — Sat, 02 May 2009 15:22:08 +0000

This is amazing, whether it turns out there are practical applications or not. Retrieving 80 million year old cells is just amazing.

By: Ed Yong

Ed Yong — Sat, 02 May 2009 12:39:58 +0000

Nathan – they did that. It was the only bit of the paper I left out because (a) the piece was getting very long and (b) it’s probably the least exciting bit about it. What you get is a phylogenetic tree that doesn’t tell us anything new beyond what bones have done in the past. The last time they did this (for the T.rex and mammoth sequences), they were slightly ridiculed for confirming hypotheses that had long been confirmed. Also the tree wasn’t great, with some species being greatly misplaced.
The new one’s better – it groups Brachylopohosaurus and Tyrannosaurus together, and places them closest to an ostrich and a chicken. The only real “mistake” is perhaps that the rex ought to group with the chicken, but I think the point is that these are only very partial sequences. Even with twice the reported amino acids of the previous paper, the Brachylophosaurus collagen sequences only represent less than 10% of the whole protein. I think that’s what Kalluri’s interested in – which areas of the protein degrade before the others?
I can definitely understand why that could be seen as reaching, although I think it’s fair to report why someone is excited about something if they genuinely are. I’ve railed before against focusing on “practical implications” over and above the actual science, but this is a case where people have actively criticised Schweitzer’s work for having no practical implications. That being so, it’s interesting then to see what her co-workers from different fields make of it.
RBH – the paper does make it clear that the key parts of the experiments (antibody-binding, collagen-sequencing) were all independently replicated in different labs, using separates bone samples. Are you looking for the entire process, from start to finish, to be completed elsewhere without Schweitzer’s involvement?

By: RBH

RBH — Sat, 02 May 2009 07:53:19 +0000

I really really REALLY want to see replication of this from a different lab.

By: Nathan Myers

Nathan Myers — Sat, 02 May 2009 05:16:42 +0000

Can these proteins be sequenced like DNA, to be compared against (e.g.) birds’ corresponding proteins? (I understand that nothing akin to PCR amplification is possible, which would make it hard, but I have not kept up on advances in this area, and would welcome being surprised.)
Ed: The remarks about treating tumors seem like extreme reaching. Am I missing something? Is he suggesting that the points at which this collagen broke would be good points to attack in tumor collagen?

By: Gunnar

Gunnar — Fri, 01 May 2009 19:13:58 +0000

I want this incorporated into a gene tree.

By: Paul Browne

Paul Browne — Fri, 01 May 2009 11:47:10 +0000

This is excellent, I can’t wait to read the paper in detail.
I was involved in some of the discussions concerning the accuaracy of the predictions made in their T.rex and Mastadon paper when it came out, and noticed that the hydroxyglycine residues they calimed were in the sequence were unlikely…something my structural biologist colleagues later ran with. It looks as if their analysis programs have got it right this time, at leastI hope that’s the case.