Preservation potential of keratin in deep time

Abstract

Multiple fossil discoveries and taphonomic experiments have established the durability of keratin. The utility and specificity of antibodies to identify keratin peptides has also been established, both in extant feathers under varying treatment conditions, and in feathers from extinct organisms. Here, we show localization of feather-keratin antibodies to control and heat-treated feathers, testifying to the repeatability of initial data supporting the preservation potential of keratin. We then show new data at higher resolution that demonstrates the specific response of these antibodies to the feather matrix, we support the presence of protein in heat-treated feathers using ToF-SIMS, and we apply these methods to a fossil feather preserved in the unusual environment of sinter hot springs. We stress the importance of employing realistic conditions such as sediment burial when designing experiments intended as proxies for taphonomic processes occurring in the fossil record. Our data support the hypothesis that keratin, particularly the β-keratin that comprises feathers, has potential to preserve in fossil remains.

Paleoproteomics of Mesozoic Dinosaurs and Other Mesozoic Fossils

“…In situ binding of antibodies to fossil tissues is thus strong evidence for the detection of peptides consistent with the target protein, not simply isolated amino acids. Furthermore, antibodies can be made against proteins not found in microbes or in mammals, and can thus be used to eliminate these potential contaminants as a source for molecular signal …”

“…"> Exogenous Contamination Should Be Monitored through the Use of Multiple, Appropriate Controls . This includes, but is not limited to, the exclusion of bacterial biofilm as a source of observed structures through chemical testing (e.g., antimicrobial antibodies show no binding), the simultaneous testing of entombing sediments and laboratory reagents with all assays to demonstrate the lack of a proteomic signal, rigorous specificity controls for all antibodies used in immunological assays, the inclusion and analyses of instrument “blank” injections in LC‐MS/MS analyses, and peptide sequences consistent with proteins from the tissue and taxa being analyzed. Multiple Independent Methods Should be Employed .…”

Sediment-encased pressure-temperature maturation experiments chemically simulate natural diagenesis of melanin

“…We thank Jakob Vinther (University of Bristol, Bristol, United Kingdom) for assistance in obtaining feather samples, discussion on feather maturation experimentation, and for his collaboration that led to the rst-generation setup reported by Saitta, Kaye 28 . Kind thanks to Peter Sjövall, RISE Research Institutes of Sweden, Borås, Sweden for providing us a reference β-keratin ToF-SIMS spectra from Schweitzer, Zheng 56 . We would also like to thank Lu-Tao Weng (…”

Ancient amino acids from fossil feathers in amber

“…Thus, identification of protein sequences from fossil feathers, combined with their morphological investigation, would allow important functional and evolutionary information to be determined over long timescales. Moreover, the preservation potential of keratin in different environments has been the subject of many recent papers 18–26 . Generally speaking, keratin is thought to have a high preservation potential in sedimentary environments, as suggested by the results of burial experiments and analyses of a number of fossil feathers 18,19,22,24–27 .…”

“…Moreover, the preservation potential of keratin in different environments has been the subject of many recent papers 18–26 . Generally speaking, keratin is thought to have a high preservation potential in sedimentary environments, as suggested by the results of burial experiments and analyses of a number of fossil feathers 18,19,22,24–27 . However, experiments focusing on diagenetic alteration report rapid degradation of keratin under increased pressure and temperature 20,23 .…”