Contractility and apoptosis in germline architecture and oogenesis

All living things are made of cells, but most cells are so tiny and closely packed that they cannot be resolved without powerful magnification. By contrast, animal eggs are exceptionally large cells; bird eggs are single enormous cells. All animals produce eggs with an elaborate cell (the germline) that has many inter-connected compartments that become eggs. In some animals, such as the one the investigators use, the germline cell operates as a conveyor belt; compartments and their contents are displaced from one end of the germline to the other as they grow. It is not known how the compartments maintain connection with each other, and how these connections change as compartments enlarge and mature. This project will uncover the mechanisms of this process. The Broader Impacts of the project include the intrinsic merit of the work itself as all animal eggs (including those of humans) utilize some form of this process. Additionally, the work will provide training opportunities for undergraduates, graduate students, and post-doctoral researchers along with high school teachers. Additional outreach work will bring science into local gradeschools.

The investigators use Caenorhabditis elegans as a model animal. The project will make use of the extensive genetics available in this system and employ state of the art live microscopic imaging approaches to observe and measure germline compartment dynamics. For compartments at different positions along the germline, and as compartments are born, die, or enlarge, the investigators will compare the size of the compartment and its associated 'doorway' to the shared central core. They also compare the amount of various cellular components on compartment walls and doorways, focusing on players that convey biochemical information or that rearrange to generate force. Not all compartments ultimately become oocytes; some undergo programmed cell death. The investigators will study the role of this process in germline architecture and oogenesis. Computer modeling will generate testable predictions that they will test with simulations and biological experiments. Execution of the research and the outreach activities will define mechanisms of cell structure and egg production, strengthen scientific research potential, and increase research diversity during the funding period and for generations to come.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.