Migrasomes are recently identified vesicular organelles that form on retraction fibres behind migrating cells. Whether migrasomes are present in vivo and, if so, the function of migrasomes in living organisms is unknown. Here, we show that migrasomes are formed during zebrafish gastrulation and signalling molecules, such as chemokines, are enriched in migrasomes. We further demonstrate that Tspan4 and Tspan7 are required for migrasome formation. Organ morphogenesis is impaired in zebrafish MZtspan4a and MZtspan7 mutants. Mechanistically, migrasomes are enriched on a cavity underneath the embryonic shield where they serve as chemoattractants to ensure the correct positioning of dorsal forerunner cells vegetally next to the embryonic shield, thereby affecting organ morphogenesis. Our study shows that migrasomes are signalling organelles that provide specific biochemical information to coordinate organ morphogenesis.

最近鉴定出了微粒体，其在迁移细胞后面的收缩纤维上形成了水泡细胞器。体内是否存在微粒体，如果存在的话，则微粒体在活生物体中的功能尚不清楚。在这里，我们显示了在斑马鱼胃气化过程中形成了微粒体，信号分子（例如趋化因子）富含了微粒体。我们进一步证明，Tspan4和Tspan7是形成微粒体所必需的。斑马鱼MZ tspan4a和MZ tspan7的器官形态发生受损突变体。从机理上讲，微粒体富集在胚胎屏障下方的腔中，在那里它们起着趋化剂的作用，以确保背侧前体细胞在植物上紧挨着胚胎屏障地正确定位，从而影响器官的形态发生。我们的研究表明，微粒体是信号传导的细胞器，可提供特定的生化信息来协调器官的形态发生。