The Kinase Regulator Mob1 Acts as a Patterning Protein for Stentor Morphogenesis

Morphogenesis and pattern formation are vital processes in any organism, whether unicellular or multicellular. But in contrast to the developmental biology of plants and animals, the principles of morphogenesis and pattern formation in single cells remain largely unknown. Although all cells develop patterns, they are most obvious in ciliates; hence, we have turned to a classical unicellular model system, the giant ciliate Stentor coeruleus. Here we show that the RNA interference (RNAi) machinery is conserved in Stentor. Using RNAi, we identify the kinase coactivator Mob1—with conserved functions in cell division and morphogenesis from plants to humans—as an asymmetrically localized patterning protein required for global patterning during development and regeneration in Stentor. Our studies reopen the door for Stentor as a model regeneration system.

形态发生（Morphogenesis）与模式形成（pattern formation）是所有生物（无论单细胞或多细胞）的核心生命过程。相较于动植物的发育生物学研究，单细胞层面的形态发生与模式形成原理迄今仍未被充分揭示。尽管所有细胞均可形成模式结构，但这一过程在纤毛虫（ciliates）中最为直观；为此，我们选择了经典单细胞模型系统——巨型纤毛虫天蓝喇叭虫（Stentor coeruleus）作为研究对象。本研究证实，RNA干扰（RNA interference, RNAi）机制在天蓝喇叭虫中具有保守性。借助RNA干扰技术，我们鉴定出激酶辅激活因子Mob1——该因子在从植物到人类的细胞分裂与形态发生过程中均具备保守功能——作为一种不对称定位的模式形成蛋白，是天蓝喇叭虫发育与再生过程中全局模式构建所必需的关键因子。本研究重新开启了将天蓝喇叭虫作为再生模型系统的研究路径。