Bird eggshells just became more colorful! For well over 100 years, only two pigments have been identified in avian eggshells: rusty-brown protoporphyrin (e.g., brown chicken eggs) and blue-green biliverdin (e.g., turquois eggs of robins). However, tinamou (chicken-like forest dwellers of South America) eggshells display unusually colored eggshells, suggesting the presence of other pigments. The Brückner group, in collaboration with the ornithologists and eggshell and bird color experts Daniel Hanley (Long Island University) and Richard Prum (Yale University), investigated this. Through extraction, derivatization, spectroscopy, chromatography, and mass spectrometry, they identified two novel eggshell pigments: yellow–brown bilirubin and red–orange uroerythrin from the guacamole-green and purplish-brown eggshells of two tinamous species. Both pigments are known porphyrin catabolites and were found in the eggshells in conjunction with biliverdin. A colour mixing model using the new pigments and biliverdin reproduced the respective eggshell colours. These discoveries expand our understanding of how eggshell colour diversity is achieved. The ability of these pigments to photo-degrade may have an adaptive value for the tinamous – this is the subject of follow-up studies for the ornithologists.
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Eggshells and Hedgehogs
Congratulations to Randy Hamchand who defended his MS Thesis with an entirely new topic for our group: The extraction of naturally occurring porphyrins/oligopyrroles in eggshells and the quills of hedgehogs. Randy will be joining the Yale graduate program in chemistry!
Congratulations Drs. Sharma and Li!
Congratulations to Meenakshi Sharma and Ruoshi Li who successfully defended their dissertations! Dr. Li tackled the modification of octaethylporphyrin, while Dr. Sharma studied a number of oxygen-based pyrrole-modified porphyrins!
Congratulations Dr. Luciano!
Mike successfully defended his thesis, and Dr. Luciano is now to a postdoctoral position at the NIH! Congratulations Mike! We will miss you in our labs!