Cilia Regeneration in the Sea Urchin Embryo: Evidence for a Pool of Ciliary Proteins

Late gastrulae of paracentrotus lividus regenerated cilia after being deciliated in hypertonic sea water. Regeneration was not affected by actinomycin D or puromycin. Actinomycin D also did not affect ciliary protein synthesis during regeneration, although overall embryonic synthesis was depressed. Puromycin inhibited both total embryonic and ciliary protein synthesis. The data indicate that ciliary protein synthesis is controlled by a stable template and that the regenerating cilia are formed from a pool of ciliary proteins. It is suggested that the proteins of the mitotic apparatus and of the ciliamay be related.