Cellular Processes and Forces Shaping the Embryo: Lessons from C. elegans

Embryo and organ shapes emerge from the interplay between genetic programs and physical forces. In recent years, there has been a growing appreciation of the role of mechanical forces in morphogenesis. Here, we review how the integration of advanced genetic approaches with high-resolution imaging, biophysics, and modeling has begun to yield new insights into C. elegans embryonic morphogenesis. Building on past reviews in the field, we analyze dorsal intercalation, ventral enclosure, and axis extension, with a focus on how forces impinge on cellular processes and serve to coordinate morphogenesis across adjacent tissues through mechanotransduction. We also discuss how different forms of cellular rosettes contribute to ventral patterning and head morphogenesis, which had not been discussed in previous reviews. Throughout, we highlight how the reciprocal feedback mechanisms between molecular processes and mechanical forces, as well as cell material properties, shape the embryo.