Kupffer's vesicle is a ciliated organ of asymmetry in the zebrafish embryo that initiates left-right development of the brain, heart and gut

Monocilia have been proposed to establish the left-right (LR) body axis in vertebrate embryos by creating a directional fluid flow that triggers asymmetric gene expression. In zebrafish, dorsal forerunner cells (DFCs) express a conserved ciliary dynein gene (left-right dynein-related1, lrdr1) and form a ciliated epithelium inside a fluid-filled organ called Kupffer's vesicle (KV). Here, videomicroscopy demonstrates that cilia inside KV are motile and create a directional fluid flow just prior to the onset of asymmetric gene expression in lateral cells. Laser ablation of DFCs and surgical disruption of KV provide direct evidence that ciliated KV cells are required during early somitogenesis for subsequent LR…