GPRiboTime · Discovering the timing and mechanisms of germplasm translation and function.

The germline is essential for reproduction and species survival, but the specialized molecular mechanisms governing its cellular program remain mysterious due to its small size. In many animals such as fish, frogs, and invertebrates, this program is encoded in the germplasm (GP), a biomolecular condensate containing RNAs and proteins inherited maternally through the egg. This project aims to uncover the mechanisms by which the germline program in zebrafish is decoded from the GP over developmental time, focusing on translational regulation of those maternal factors. The first objective is to systematically catalogue the components of the GP over early embryogenesis as the germline undergoes a conserved series of steps to establish itself in the gonad. This will be achieved by proximity labelling of GP components to enable its enrichment for downstream RNA sequencing and proteomic analysis, generating data that will be integrated into quantitative models of GP dynamics and regulation. The second objective will explore how the RNAs, stored inactive in the GP interior, are sequentially accessed through translation at the GP periphery to support the sequence of germline development. The third objective will test the function of known and novel GP components by knockdown or overexpression, thereby uncovering the timing and nature of individual molecules’ contribution to germline function. These objectives will benefit from interdisciplinary, sensitive techniques for analysis, such as low-input proteomics, super-resolution imaging, and cryo-electron tomography, that will overcome the challenges of working with limited material. In doing so this project will detail mechanisms of localized translational and biomolecular condensate regulation, findings that extend its impact beyond the zebrafish germline to a broad range of biological systems. This work will strengthen my interdisciplinary skills and scientific independence as I prepare to establish my own research group.