Fatieieva Yuliia, Galimullina Rozalina, Isaev Sergey, Klimovich Alexander, Lemaire Laurence A, Adameyko Igor
Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, 1090, Vienna, Austria.
Zoological Institute, Christian-Albrechts University of Kiel, 24118, Kiel, Germany.
Commun Biol. 2025 Jul 23;8(1):1092. doi: 10.1038/s42003-025-08502-0.
In vertebrates, two major cell types produce extensive pigmentation: neuroepithelium-derived retinal pigment epithelium (RPE) of the eye and neural crest-derived melanocytes. Both produce melanin, express opsins, and exhibit photosensory functions. However, the evolutionary relationship between these cells - whether pigmentation was coopted or they share a common ancestry - remains unclear. We explore these scenarios including the hypothesis of a shared origin from an ancestral pigmented photosensory structure. For this, we harness single cell transcriptomics, chromatin accessibility and spatial transcriptomics data, to connect the transcriptional programs in melanocytes, pinealocytes and RPE with that of the pigmented cells in the sensory vesicle of the tunicate Ciona. The results reveal common regulatory gene expression modules spanning beyond pigment production, including photoreception, metabolism and biosynthesis. This evidence does not favor a model where pigmentation was coopted into one of these cell types, and rather supports the homology of melanocytes and RPE. Further, phylotranscriptomics approach expose recently-evolved melanocyte-specific and RPE-specific functions, which diversified after these types split from the ancestral cell type. Overall, our results support that melanocytes and RPE evolved from ancestral pigmented photosensory structures in chordates, initiating the origin of the neural crest - a major evolutionary driver of the vertebrate lineage.
在脊椎动物中，有两种主要的细胞类型会产生广泛的色素沉着：眼睛中神经上皮衍生的视网膜色素上皮（RPE）和神经嵴衍生的黑素细胞。这两种细胞都会产生黑色素，表达视蛋白，并具有光感功能。然而，这些细胞之间的进化关系——色素沉着是被借用的，还是它们有着共同的祖先——仍不清楚。我们探讨了这些情况，包括它们起源于一个祖先色素沉着光感结构的假说。为此，我们利用单细胞转录组学、染色质可及性和空间转录组学数据，将黑素细胞、松果体细胞和RPE中的转录程序与被囊动物海鞘感觉泡中的色素沉着细胞的转录程序联系起来。结果揭示了跨越色素产生的共同调控基因表达模块，包括光感受、代谢和生物合成。这一证据不支持色素沉着被引入其中一种细胞类型的模型, 而是支持黑素细胞和RPE的同源性。此外，系统发育转录组学方法揭示了最近进化出的黑素细胞特异性和RPE特异性功能，这些功能在这些细胞类型从祖先细胞类型分化后发生了多样化。总体而言，我们的结果支持黑素细胞和RPE起源于脊索动物的祖先色素沉着光感结构，开启了神经嵴的起源——脊椎动物谱系的一个主要进化驱动力。
