Carcharodontosaurus Posted June 4, 2014 Author Share Posted June 4, 2014 I talked about the enamel problem with an online friend of mine, who studies bioinformatics in the Netherlands. According to him, the paper "The evolution of the avian genome as revealed by comparative molecular cytogenetics" by Griffin et al. compared the chromosomes of birds and turtles and found that while chicken chromosome 4 (the chromosome where the enamel pseudogene is located) has had fusions with other chromosomes and has had rearrangements, the chromosomes of rheas, emus, mallards and a few other birds are still unaltered. I haven't read the paper myself (paywall), so I have no idea if it really says that, but if it is true, is it possible that some ratites like emus and ostriches might still have functional enamel genes? Link to comment Share on other sites More sharing options...
Mediospirifer Posted June 4, 2014 Share Posted June 4, 2014 Interesting! Can you post the journal reference? I can probably get it while I'm at work on Thursday. If the gene sequences aren't broken, then it is theoretically possible, or at least closer to possible than starting with a chicken. Whoever tried it would still have to figure out how to control the gene expression to initiate tooth formation. Link to comment Share on other sites More sharing options...
Carcharodontosaurus Posted June 4, 2014 Author Share Posted June 4, 2014 Interesting! Can you post the journal reference? I can probably get it while I'm at work on Thursday. If the gene sequences aren't broken, then it is theoretically possible, or at least closer to possible than starting with a chicken. Whoever tried it would still have to figure out how to control the gene expression to initiate tooth formation. You can pay to view it here, but I don't have the money: http://www.karger.com/Article/FullText/103166 Link to comment Share on other sites More sharing options...
Mediospirifer Posted June 4, 2014 Share Posted June 4, 2014 You can pay to view it here, but I don't have the money: http://www.karger.com/Article/FullText/103166 I don't either, but the lab I work for probably has access to a library subscription. In which case, I can access it through the online catalog from my desk. I'll check it out on Thursday, and let you know my opinion. Thanks! Link to comment Share on other sites More sharing options...
Mediospirifer Posted June 9, 2014 Share Posted June 9, 2014 I got the paper and read through it. It's very interesting! Basically, the paper describes the chromosome arrangements of part of the avian genome. They mainly focus on comparing the genome across different groups of birds, with mammals as an outlier (we share chromosome 4 alone of these 9 or 10 chromosomes with birds, the rest evolved after the lineages split). They show how different groups of birds have had fission or fusion events to rearrange these chromosomes, with ratites being closest to the ancestral arrangement. Yes, they do say that chromosome 4 in ratites has not been rearranged. They don't discuss any specific genes at all. Your friend may have other information that does discuss the specific gene for enamelin, but I wouldn't draw the conclusion that any specific unexpressed gene is unaltered based solely on this paper. I'm not sure whether the likelihood of ratites having a functional enamelin gene is different from other bird groups or not, although a lineage that has had a chromosome split in that region probably had something rendered nonfunctional as a result. It would be interesting to have someone look! Thanks for the link! Link to comment Share on other sites More sharing options...
Carcharodontosaurus Posted June 9, 2014 Author Share Posted June 9, 2014 I got the paper and read through it. It's very interesting! Basically, the paper describes the chromosome arrangements of part of the avian genome. They mainly focus on comparing the genome across different groups of birds, with mammals as an outlier (we share chromosome 4 alone of these 9 or 10 chromosomes with birds, the rest evolved after the lineages split). They show how different groups of birds have had fission or fusion events to rearrange these chromosomes, with ratites being closest to the ancestral arrangement. Yes, they do say that chromosome 4 in ratites has not been rearranged. They don't discuss any specific genes at all. Your friend may have other information that does discuss the specific gene for enamelin, but I wouldn't draw the conclusion that any specific unexpressed gene is unaltered based solely on this paper. I'm not sure whether the likelihood of ratites having a functional enamelin gene is different from other bird groups or not, although a lineage that has had a chromosome split in that region probably had something rendered nonfunctional as a result. It would be interesting to have someone look! Thanks for the link! He didn't say it discussed genes. He just said that maybe since ratite chromosomes are closest to the ancestral genome, they may retain enamelin genes. Like you said, someone would need to look at a ratite genome. Link to comment Share on other sites More sharing options...
Carcharodontosaurus Posted July 2, 2014 Author Share Posted July 2, 2014 Another paper caught my eye. However, there isn't even an abstract on the internet available for it. It is written by Hans Larsson, and was published in the 2006 SVP annual meeting. It is titled Developmental mechanisms implicated in the evolution of theropod-avian tail reduction. It might or might not be relevant to this, but to make sure, would anybody be kind enough to read for me if they have access to it? Link to comment Share on other sites More sharing options...
Mediospirifer Posted July 2, 2014 Share Posted July 2, 2014 Unfortunately, I can't find access through my library catalog. Otherwise, I'd be happy to look it up! Good luck! Link to comment Share on other sites More sharing options...
Carcharodontosaurus Posted November 11, 2014 Author Share Posted November 11, 2014 Finally, some news for this project: http://www.washingtonpost.com/national/health-science/paleontologist-jack-horner-is-hard-at-work-trying-to-turn-a-chicken-into-a-dinosaur/2014/11/10/cb35e46e-4e59-11e4-babe-e91da079cb8a_story.html Link to comment Share on other sites More sharing options...
Mediospirifer Posted November 11, 2014 Share Posted November 11, 2014 So they expect teeth to be easier to recreate than the tail? Interesting. I'd like to see the paper describing Harris' tooth-budding embryos! Specifically, I'm curious about his methods, and what the embryonic faces look like. I also note that they are planning to insert the enamelin gene from another critter, but don't say which critter. Mouse seems a likely choice, just because they've also been studied extensively. Whatever the end result, it will be interesting to see! I do find it amusing that George Lucas is financing the project. Very cool! Link to comment Share on other sites More sharing options...
Carcharodontosaurus Posted November 11, 2014 Author Share Posted November 11, 2014 So they expect teeth to be easier to recreate than the tail? Interesting. I'd like to see the paper describing Harris' tooth-budding embryos! Specifically, I'm curious about his methods, and what the embryonic faces look like. I also note that they are planning to insert the enamelin gene from another critter, but don't say which critter. Mouse seems a likely choice, just because they've also been studied extensively. Whatever the end result, it will be interesting to see! I do find it amusing that George Lucas is financing the project. Very cool! I think it is this paper, which you have probably already read: http://www.ncbi.nlm.nih.gov/pubmed/16488870 Link to comment Share on other sites More sharing options...
Mediospirifer Posted November 11, 2014 Share Posted November 11, 2014 I think it is this paper, which you have probably already read: http://www.ncbi.nlm.nih.gov/pubmed/16488870 Okay. I was wondering if they had something other than talpid2 worked out. The WP article didn't mention the deformities that went along with the talpid2 expression, just that they had early-stage developing teeth. It came across as a closer-to-being-solved aspect of the problem than it appears from the talpid2 paper. And yes, I did read that article. I just didn't recall who the authors were immediately. The research they describe in tail development is cool, too. Link to comment Share on other sites More sharing options...
New Members Neoraptor philadelphensis Posted October 27, 2015 New Members Share Posted October 27, 2015 Greetings All, I have followed Horner et al. and their dinochicken/chickenosaurus . One thing from reading about the tooth development, it almost seems impractical to give a living creature teeth that will not fully develop. Perhaps he should leave the beak, so the creature can eat at least. And speaking of diet, I have cousins who raise chickens. Left to their own devices, they will peck at plants, seeds, buds, bugs (flying and crawling), grubs, worms, and even peck at frogs, snakes, mice. Chickens instinctively go after "anything that moves". A dinochicken would have little problem cultivating a more omnivorous, or perhaps even a carnivorous diet, with a little guidance and coaxing. Another thing I have a concern about is the motility/utlity of the dinochicken's hands. It would be a great disservice to the living animal if it's clawed digits remained tightly tucked up against the sides of its body, or limply dangling. Humans can express a tail, but there's no guarantee it is a moving tail,. let alone a prehensile tail (!) It's one thing to genetically express the claws on a hand, its another to ensure they have some grasp/prehensility and further utility to the animal. Once hatched, the people who'll raise these new dinochickens will have their hands full for sure. Very interesting. I cannot wait to read more as it develops. Link to comment Share on other sites More sharing options...
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