Division of International Affairs, Headquaters, National Institute of Technology, Tokyo, Japan.
Department of Creative Engineering, National Institute of Technology, Kitakyushu, Japan.
Elife. 2022 Oct 11;11:e71920. doi: 10.7554/eLife.71920.
A diversity of prokaryotes currently exhibit multicellularity with different generation mechanisms in a variety of contexts of ecology on Earth. In the present study, we report a new type of multicellular bacterium, HS-3, isolated from an underground stream. HS-3 self-organizes its filamentous cells into a layer-structured colony with the properties of a nematic liquid crystal. After maturation, the colony starts to form a semi-closed sphere accommodating clusters of coccobacillus daughter cells and selectively releases them upon contact with water. This is the first report that shows that a liquid-crystal status of cells can support the prokaryotic multicellular behavior. Importantly, the observed behavior of HS-3 suggests that the recurrent intermittent exposure of colonies to water flow in the cave might have been the ecological context that cultivated the evolutionary transition from unicellular to multicellular life. This is the new extant model that underpins theories regarding a role of ecological context in the emergence of multicellularity.
目前，多种多样的原核生物在地球的各种生态环境中表现出了多细胞特性，其具有不同的世代机制。在本研究中，我们报告了一种来自地下溪流的新型多细胞细菌 HS-3。HS-3 丝状细胞自我组织成具有向列液晶特性的层状菌落。成熟后，菌落开始形成一个半封闭球体，容纳球菌状子细胞簇，并在与水接触时选择性地释放它们。这是第一个表明细胞的液晶状态可以支持原核多细胞行为的报告。重要的是，HS-3 的观察行为表明，菌落反复间歇性地暴露于洞穴中的水流可能是生态环境，促使从单细胞到多细胞生命的进化转变得以发生。这是新的现存模型，为生态环境在多细胞性出现中的作用提供了理论基础。
