Expanding the eggshell colour gamut: uroerythrin and bilirubin from tinamou (Tinamidae) eggshells
Expanding the eggshell colour gamut: uroerythrin and bilirubin from tinamou (Tinamidae) eggshells
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DOI：
10.1038/s41598-020-68070-7
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发表时间：
2020-07-09
影响因子：
4.6
通讯作者：
Bruckner, Christian
中科院分区：
文献类型：
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作者：
Hamchand, Randy;Hanley, Daniel;Bruckner, Christian
到目前为止，在禽类蛋壳中只发现了两种色素：锈棕色的原卟啉IX和蓝绿色的胆绿素IXα。大多数禽类蛋壳的颜色都可以由这两种四聚吡咯颜料混合而成。然而，Tinamou(Tinamidae)蛋壳显示的颜色仅靠这两种色素的组合很难合理化，这表明存在其他色素。在这里，通过提取、衍生化、光谱、层析和质谱分析，我们鉴定了两种新的蛋壳色素：从龙须菜的鳄梨色-绿色蛋壳中提取的黄褐色四吡咯胆红素和从紫褐色蛋壳中提取的红橙色三吡咯尿红蛋白。这两种色素都是已知的卟啉分解代谢物，并与胆绿素IXα一起存在于蛋壳中。使用新颜料和胆绿素的混色模型再现了各自的蛋壳颜色。这些发现扩大了我们对蛋壳颜色多样性是如何实现的理解。我们认为，这些色素的光降解能力可能有适应价值的马蹄铁。
To date, only two pigments have been identified in avian eggshells: rusty-brown protoporphyrin IX and blue-green biliverdin IX alpha. Most avian eggshell colours can be produced by a mixture of these two tetrapyrrolic pigments. However, tinamou (Tinamidae) eggshells display colours not easily rationalised by combination of these two pigments alone, suggesting the presence of other pigments. Here, through extraction, derivatization, spectroscopy, chromatography, and mass spectrometry, we identify two novel eggshell pigments: yellow-brown tetrapyrrolic bilirubin from the guacamole-green eggshells of Eudromia elegans, and red-orange tripyrrolic uroerythrin from the purplish-brown eggshells of Nothura maculosa. Both pigments are known porphyrin catabolites and are found in the eggshells in conjunction with biliverdin IX alpha. A colour mixing model using the new pigments and biliverdin reproduces the respective eggshell colours. These discoveries expand our understanding of how eggshell colour diversity is achieved. We suggest that the ability of these pigments to photo-degrade may have an adaptive value for the tinamous.