Bioluminescence has been recognized as an important means for inter- and intra-species communication. A growing number of reports of red fluorescence occurring in keratinaceous materials have become available. The fluorophore(s) in these cases were shown to be, or suspected to be, free base porphyrins. The red fluorescence found in the downs of bustards was associated with inter-species signaling in mate selection. First reported in 1925, we confirm that spines of the European hedgehog (Erinaceus europaeus) when irradiated with UV (365–395 nm) light display red fluorescence localized in the light-colored sections of their proximal ends. Using reflectance fluorescence spectroscopy, we confirmed that the fluorophores responsible for the emission are free-base porphyrins, as suspected in the original report. Base-induced degradation of the spine matrix and subsequent HPLC, UV-vis, and ESI+ mass spectrometry analysis revealed the presence of a mixture of coproporphyrin III and uroporphyrin III as predominant porphyrins and a minor fraction of protoporphyrin IX. Investigation of the spine microbiome uncovered the abundant presence of bacteria known to secrete and/or interconvert porphyrins and that are not present on the non-fluorescing quills of the North American porcupine (Erethizon dorsatum). Given this circumstantial evidence, we propose the porphyrins could originate from commensal bacteria. Furthermore, we hypothesize that the fluorescence may be incidental and of no biological function for the hedgehog.

生物发光已被公认为是种间和种内交流的重要手段。越来越多的关于角蛋白材料中发生红色荧光的报道已经变得可用。这些情况下的荧光团被证明是或怀疑是游离碱卟啉。在鸨的羽绒中发现的红色荧光与配偶选择中的种间信号传导有关。1925 年首次报道，我们证实欧洲刺猬 ( Erinaceus europaeus) 当用 UV (365–395 nm) 光照射时，会显示红色荧光，位于其近端的浅色部分。使用反射荧光光谱，我们确认负责发射的荧光团是游离碱卟啉，正如原始报告中所怀疑的那样。脊柱基质的碱诱导降解和随后的 HPLC、UV-vis 和 ESI+ 质谱分析表明存在粪卟啉 III 和尿卟啉 III 作为主要卟啉和少量原卟啉 IX 的混合物。对脊柱微生物组的研究发现，大量存在已知可分泌和/或相互转化卟啉的细菌，而北美豪猪（Erethizon dorsatum）。鉴于这种间接证据，我们认为卟啉可能来自共生细菌。此外，我们假设荧光可能是偶然的，对刺猬没有生物学功能。