Beta-keratin (
Keratin (avian) | |||||||||
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Identifiers | |||||||||
Symbol | Keratin | ||||||||
Pfam | PF02422 | ||||||||
InterPro | IPR003461 | ||||||||
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The scales, beaks, claws and feathers of birds contain
Changes in
The small alvarezsaurid dinosaur Shuvuuia deserti shows evidence of a featherlike skin covering. Analysis by Schweitzer et al. (1999) showed that these featherlike structures consisted of beta-keratin.[8] This has since been refuted by Saitta et al., finding that the fibers analyzed instead consisted of inorganic calcium phosphate as evidenced by fluorescence under cross polarised light.[9] Signals from immunohistochemical analyses on fossil samples are prone to false positives and must be used with caution when dealing with geological samples.
References edit
- ^ Dalla Valle L, Nardi A, Belvedere P, Toni M, Alibardi L (July 2007). "Beta-keratins of differentiating epidermis of snake comprise glycine-proline-serine-rich proteins with an avian-like gene organization". Dev. Dyn. 236 (7): 1939–53. doi:10.1002/dvdy.21202. PMID 17576619.
- ^ Dalla Valle L, Nardi A, Toffolo V, Niero C, Toni M, Alibardi L (February 2007). "Cloning and characterization of scale beta-keratins in the differentiating epidermis of geckoes show they are glycine-proline-serine-rich proteins with a central motif homologous to avian beta-keratins". Dev. Dyn. 236 (2): 374–88. doi:10.1002/dvdy.21022. PMID 17191254.
- ^ a b Calvaresi M, Eckhart L, Alibardi L (June 2016). "The molecular organization of the beta-sheet region in Corneous beta-proteins (beta-keratins) of sauropsids explains its stability and polymerization into filaments". J. Struct. Biol. 194 (3): 282–91. doi:10.1016/j.jsb.2016.03.004. PMID 26965557.
- ^ Alibardi L (Feb 2013). "Cornification in reptilian epidermis occurs through the deposition of keratin-associated beta-proteins (beta-keratins) onto a scaffold of intermediate filament keratins". J. Morphol. 274 (2): 175–93. doi:10.1002/jmor.20086. PMID 23065677. S2CID 23739887.
- ^ Greenwold, M.J.; Sawyer, R.H. (2010). "Genomic organization and molecular phylogenies of the beta (
β ) keratin multigene family in the chicken (Gallus gallus) and zebra finch (Taeniopygia guttata): implications for feather evolution". BMC Evolutionary Biology. 10: 148. doi:10.1186/1471-2148-10-148. PMC 2894828. PMID 20482795. - ^ a b c Greenwold, M.J.; Sawyer, R.H. (2011). "Linking the molecular evolution of avian beta (
β ) keratins to the evolution of feathers". Journal of Experimental Zoology. 316B (8): 609–616. Bibcode:2011JEZB..316..609G. doi:10.1002/jez.b.21436. PMID 21898788. - ^ Nudds, R.L.; Dyke, G.J. (14 May 2010). "Narrow Primary Feather Rachises in Confuciusornis and Archaeopteryx Suggest Poor Flight Ability". Science. 328 (5980): 887–889. Bibcode:2010Sci...328..887N. doi:10.1126/science.1188895. PMID 20466930. S2CID 12340187.
- ^ .Schweitzer, Mary Higby, Watt, J.A., Avci, R., Knapp, L., Chiappe, L, Norell, Mark A., Marshall, M. (1999). "Beta-Keratin Specific Immunological reactivity in Feather-Like Structures of the Cretaceous Alvarezsaurid, Shuvuuia deserti Journal of Experimental Biology (Mol Dev Evol) 255:146-157
- ^ .Saitta, Evan T., Fletcher, I., Martin, P., Pittman, M., Kaye, Thomas G., True, Lawrence D., Norell, Mark A., Abbott, Geoffrey D., Summons, Roger E., Penkman, K., Vinther, J. (2018). "Preservation of feather fibers from the Late Cretaceous dinosaur Shuvuuia deserti raises concern about immunohistochemical analyses on fossils". Organic Geochemistry 125:142-151
External links edit
- beta-Keratins at the U.S. National Library of Medicine Medical Subject Headings (MeSH)