Characterizing a Role for the Misshapen Kinase in Growth of the Germline Ring Canals in the Developing Egg Chamber

Ashley Kline Butler University
Faculty Sponsor(s): Lindsay Lewellyn Butler University
Fruit fly oogenesis is a complex developmental process that is divided into 14 morphologically distinct stages. The developing egg chamber is composed of a central cluster of germ cells (1 oocyte and 15 nurse cells) surrounded by a layer of somatic epithelial cells. The nurse cells are connected to each other and to the oocyte through large intercellular bridges called ring canals. Ring canals are f-actin-rich structures that arise through incomplete cytokinesis during formation of the germ cell cluster, and they are essential to allow the transfer of materials from the nurse cells to the oocyte. During stage 11 of oogenesis, the nurse cells rapidly transfer their cytoplasmic contents to the oocyte. To accommodate this transfer, the ring canals undergo a significant expansion to reach a final diameter of 10 µm. Although a number of structural and regulatory components have been identified, there is still much to be learned about ring canal formation, stabilization, and expansion. We have identified a novel role for the Misshapen (Msn) kinase in growth and stability of the ring canals. Depletion of Msn by RNAi does not disrupt ring canal formation or the recruitment of other ring canal components, such as Hts-RC and Kelch. However, we see a significant defect in ring canal expansion. Furthermore, the overexpression of a membrane-tethered form of Msn often causes ring canal collapse, leading to the formation of multinucleate nurse cells. Further experiments are necessary to determine the mechanism and timing underlying Misshapen’s role in ring canal stabilization and growth.
Oral Presentation

When & Where

12:00 PM
Gallahue Hall 101