Syncytium biogenesis: It's all about maintaining good connections.

At the end of mitosis, cells typically complete their division with cytokinesis. In certain tissues however, incomplete cytokinesis can give rise to cells that remain connected by intercellular bridges, thus forming a syncytium. Examples include the germline of many species, from fruitfly to humans, yet the mechanisms regulating syncytial formation and maintenance is unclear, and the biological relevance of syncytial organization remains largely speculative. To better understand these processes, we recently used the germline of Caenorhabditis elegans as a model for syncytium development. Analysis of the germline syncytial architecture throughout development revealed that it arises progressively during larval growth and that it relies on the activity of 2 actomyosin scaffold proteins of the Anillin family. Our work also showed that the gonad can sustain elastic deformation when under mechanical stress and that this property may be conferred by the malleability of syncytial openings. We suggest that elasticity and resistance to mechanical stress constitutes a general property of syncytial tissues.