A Novel Role of UAP56 in piRNA Mediated Transposon Silencing: A Dissertation

iii Dedications To my dear parents, who always encourage me to reach high; To my wonderful husband, Hanhui, who always backs me up without a word; To my sweet boys, Tian and Hai, who are my real motivations to move forward. iv Acknowledgements Seven years ago, when I first knocked on his office door, my thesis advisor, Dr. William Theurkauf, welcomed me with his profound scientific insight and bright personality. I was fortunate to join his lab and involved in this exciting project. I truly enjoyed my graduate study. With all sorts of great ideas and discussions, Bill kept on inspiring me and encouraging me to pursue something new. He taught me not to afraid of challenges and conquers myself. Sometimes when I felt stuck, his optimism kept my spirit up. With all sorts of collaborations drawn in by his open mind and wide connections, we were able to moving beyond our abilities. Whenever there was a little progress, his great appreciation made me feel fulfilled. As a daughter, a wife and a mother, I sometimes struggled between the balance of my family life and my professional career. Bill always very understood and his support really empowered me to overcome all the difficulties and finally finished my Ph.D. I wish I could carry all the great things he has taught me through all these years and pass it on to my new career and new life ahead. committee. Their continuous scientific input and encouragement guided me through each little step of my graduate study. Second, I would like to thank all the great people I worked with in Theurkauf lab. Beatrice Benoit was the first postdoc I worked with. She taught me the fly genetics from the very beginning by holding my hand. And Nadine Schultz was like a live dictionary of fly genetics and she magically solved almost all my fly issues. She was also a faithful v listener of all my happiness and worries and never hesitated to offer help. Birgit Koppetsch, with her specialties of confocal microscopy and image analysis, her valuable contribution to this project is indispensable. I am thankful to my fellow graduate student, Zhao Zhang, for preparing small RNA library and all the technical support of RNA-Seq library preparation. And I deeply appreciate Travis Thomson for comments and helping revise my thesis. It was a great pleasure to collaborate with Dr. Zhiping Weng and …