Cryptophytes are known to vary widely in coloration among species. These differences in color arise primarily from the presence of phycobiliprotein accessory pigments. There are nine defined cryptophyte phycobiliprotein (Cr-PBP) types, named for their wavelength of maximal absorbance. Because Cr-PBP type has traditionally been regarded as a categorical trait, there is a paucity of information about how spectral absorption characteristics of Cr-PBPs vary among species. We investigated variability in primary and secondary peak absorbance wavelengths and full width at half max (FWHM) values of spectra of Cr-PBPs extracted from 75 cryptophyte strains (55 species) grown under full spectrum irradiance. We show that there may be substantial differences in spectral shapes within Cr-PBP types, with Cr-Phycoerythrin (Cr-PE) 545 showing the greatest variability with two, possibly three, subtypes, while Cr-PE 566 spectra were the least variable, with only ±1 nm of variance around the mean absorbance maximum of 565 nm. We provide additional criteria for classification in cases where the wavelength of maximum absorbance alone is not definitive. Variations in spectral characteristics among strains containing the same presumed Cr-PBP type may indicate differing chromophore composition and/or the presence of more than one Cr-PBP in a single cryptophyte species.

中文翻译：

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隐植物藻胆蛋白类型内光谱吸收的变化

已知隐植物的颜色在不同物种之间差异很大。这些颜色差异主要是由于藻胆蛋白辅助色素的存在造成的。有九种已定义的隐植物藻胆蛋白 (Cr-PBP) 类型，以其最大吸光度波长命名。由于 Cr-PBP 类型传统上被视为一种分类性状，因此缺乏有关 Cr-PBP 光谱吸收特性在物种之间如何变化的信息。我们研究了从在全光谱辐照度下生长的 75 个隐植物菌株（55 个物种）中提取的 Cr-PBP 光谱的初级和次级峰值吸收波长和半峰全宽 (FWHM) 值的变化。我们表明，Cr-PBP 类型内的光谱形状可能存在显着差异，其中 Cr-藻红蛋白 (Cr-PE) 第 545 章显示出最大的变异性，有两种（可能是三种）亚型，而 Cr-PE 566 光谱变化最小，平均吸光度最大值 565 nm 周围仅有 ±1 nm 的方差。在最大吸光度波长本身不确定的情况下，我们提供了额外的分类标准。含有相同假定 Cr-PBP 类型的菌株之间光谱特征的变化可能表明不同的生色团组成和/或单个隐植物物种中存在超过一种 Cr-PBP。