Cells constantly navigate confined spaces, where mechanical forces shape their fate. Our work explores how confinement influences stem cell differentiation and germ cell maturation. We have shown that mechanical constraints drive lineage specification in stem cells, revealing confinement as a key regulator of cell fate. Extending this to primordial germ cells (PGCs), we propose that the highly confining embryonic environment forces nuclear deformation, triggering epigenetic remodeling essential for germline maturation. Using zebrafish embryos and engineered microenvironments, we demonstrate that migrating PGCs undergo significant nuclear reshaping, potentially safeguarding their genome during transit. By integrating in vivo and in vitro models, we aim to uncover how physical forces contribute to germline development and broader mechanobiological processes.