Zebrafish posterior lateral line development

The lateral line is a sensory system in fish composed of neuromast cells, which detect vibrations in the water. This image shows the development of the lateral line in a 55 hour old zebrafish embryo containing a mutated form of the gene lef1. The lateral line is produced by a cluster of migratory cells called the posterior lateral line primordium (PLLP), and lef1 is a Wnt-pathway transcription factor required to maintain proliferation in the PLLP progenitor pool as the primordium migrates along the tail, periodically depositing neuromasts (green). The nuclei (DNA storage site) of cells of the PLPP are seen in red. Width of image is 300 micrometres.