Ribosome heterogeneity has been revealed to exist in different cell types during development. However, the function and regulatory mechanisms of ribosome heterogeneity in missing tissue regeneration have yet to be reported. We used the planarian Schmidtea mediterranea with whole-body regenerative capability as a model and revealed the function of the rRNA modification protein fibrillarin in cell lineage development and tissue regeneration. We identified two fibrillarin homologs in planarian, Smed-fbl-1 (fbl-1) and Smed-fbl-2 (fbl-2), with distinct expression patterns. While fbl-2 regulates stem cell proliferation and multiple progenitor cell differentiation, fbl-1 participates in epidermal lineage late-stage specification and wound response. This study indicates that fibrillarin, a nucleolar protein, can respond to wounds and function in distinct cell types, suggesting the existence and critical roles of ribosome heterogeneity in stem cells and tissue regeneration.

中文翻译：

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Fibrillarin-1 和 Fibrillarin-2 是涡虫稳态和再生中分化细胞谱系发育所必需的

已发现核糖体异质性在发育过程中存在于不同的细胞类型中。然而，尚未报道核糖体异质性在缺失组织再生中的功能和调节机制。我们以具有全身再生能力的涡虫Schmidtea mediterranea作为模型，揭示了 rRNA 修饰蛋白原纤维蛋白在细胞谱系发育和组织再生中的作用。我们在涡虫中鉴定了两种原纤维蛋白同源物，Smed-fbl-1 ( fbl-1 ) 和Smed-fbl-2 ( fbl-2 )，具有不同的表达模式。fbl -2调节干细胞增殖和多祖细胞分化，而 fbl-1参与表皮谱系后期规范和伤口反应。这项研究表明，原纤维蛋白是一种核仁蛋白，可以对不同细胞类型的伤口和功能作出反应，表明核糖体异质性在干细胞和组织再生中的存在和关键作用。