As the major microtubule organizing center in metazoan cells, centrosomes play key roles in mitotic spindle assembly, cell signaling, polarity, and motility.1 Additionally, centrosomal dysfunction is associated with a broad range of disorders from tumors to ciliopathies.1 Visualizing these organelles in vivo in a broad range of cell biological contexts would help better elucidate their roles in physiological and disease conditions. In an article on adaptive optics, Wang et al. used a novel transgenic line to image centrosomes in vivo in larval zebrafish.2 In this line, which we call CentrinFish, centrosomes and cellular membranes are labeled by spectrally distinct fluorescent proteins, permitting their simultaneous visualization (Fig. 1). Thus, centrosome localization and dynamics can be studied within a cellular context. Moreover, because the reporters are driven by UAS cassettes, expression can be targeted to specific cell types by crossing CentrinFish to appropriate Gal4-driver lines. FIG. 1. The CentrinFish transgene construct contains two UAS reporter cassettes, centrin4-YFP to label centrosomes (cetn4-YFP) and an N-terminal palmitoylation sequence from neuromodulin to target Cerulean to the plasma membrane (MA-Cerulean). An additional cassette ...