School of Science Division of Life Science 37 Niche Regulation of Stem Cell Self-renewal, Differentiation and Ageing Supervisor: XIE Ting / LIFS Co-supervisor: TU Renjun / LIFS Student: WONG Sze Chai Helen / IRE Course: UROP1100, Summer The Drosophila ovary harbors a community of germline stem cells to produce oocytes for reproduction, yet some of the detailed genetic and molecular mechanisms remain unknown. Thus, a preliminary genetic screening is particularly effective in searching for genes controlling germline stem cell development. By using the Gal4-UAS system to carry out RNA interference and silence selected kinase genes, we successfully identify fj, for, fu, fwd, Galk and gish as genes involved in Drosophila ovarian germline stem cell development. In addition, fs(1)h and fray are discovered to regulate ovary development. Results of this genetic screening have paved the way for future studies on the molecular pathways regulating germline stem cell self-renewal and differentiation. Niche Regulation of Stem Cell Self-renewal, Differentiation and Ageing Supervisor: XIE Ting / LIFS Co-supervisor: TU Renjun / LIFS Student: ZHAO Yicheng / CHEM Course: UROP1100, Fall In the Drosophila ovary, a small number of cells can maintain their ability to self-renew and generate daughter cells that can further differentiate, and these cells are referred to as stem cells. Germline stem cell (GSC) is one of the best models to study the molecular and genetic mechanisms that how stem cell selfrenewal and differentiation are controlled in vivo. They are located in a structure named germarium, which is at the tip of the ovary. GSCs can differentiate into oocytes and can be readily identified by observing their fusomes. Within GSCs, RNA binding proteins play a vital role in the cell’s gene expression, specifically affecting RNA processing, export, localization, and translation. In this project, we try to study the subcellular localization of some RNA-binding proteins in the Drosophila ovary, using the method of Drosophila ovary immunostaining. We found that Imp and Fmr1 are expressed in the cytoplasm, while CG5728 and nonA-I are localized in nuclear, indicating they play different roles in regulating germline development. In the future study, we will investigate which RNAs are associated with these RNA binding proteins, and the molecular functions that how these RNA binding proteins regulate RNA metabolism.