Piwi-interacting RNAs (piRNAs) have been implicated in defending the germline genome against the deleterious retroelements. Most of the piRNA pathway components have been shown to localize to the nuage, a unique perinuclear structure found in the animal germlines. Recently, a tudor domain protein Tejas that localizes to the nuage, has been reported to be involved in the germline piRNA pathway in Drosophila. Later, a homolog of Tejas, Tapas, was also found to be functioning in the piRNA pathway and localize to the nuage in Drosophila. Here, I report the characterization of Tapas for its role in the piRNA pathway. I show that tapas is involved in the hierarchical assembly of nuage: the proper localization of Vasa, Spindle-E, Tejas, Aubergine, Krimper, Argonaute 3 and Maelstrom to the nuage depends on tapas, and localization of Tapas is independent of any of the known nuage components. These results suggest that tapas probably functions upstream in the hierarchical assembly. Further, I found that Tapas physically interacts with some of the piRNA pathway components such as Aubergine, Argonaute3, Vasa, Tejas and Spindle-E. These results imply that Tapas probably aids in the formation of macromolecular complex at the perinuclear region, supporting the idea that piRNA components form a macrocomplex or sub-complexes at the perinuclear nuage by being engaged in piRNAs production.Bachelor of Science in Biological Science
