Mammalian eggs store embryonic building blocks on a physical 3D grid to keep them inactive until development begins.
April 1, 2026
Original Paper
The cytoplasmic lattice in mammalian eggs sequesters ubiquitination machinery and tubulin in reserve
bioRxiv · 10.64898/2026.03.30.715190
The Takeaway
Scientists discovered a highly organized 'cytoplasmic lattice' that acts like a structural warehouse within the egg. It physically sequesters essential machinery—including the cell's skeleton and protein-recycling systems—in a 'ready-to-use' but dormant state, preventing them from accidentally activating until after fertilization.
From the abstract
The cytoplasmic lattice (CPL) in mammalian eggs is essential for early embryonic development, but its molecular components, structural organization, and functional capacity have remained elusive. Here, using cryo-electron microscopy, we show that the CPL filament in mouse eggs contains repeating units with a periodicity of ~37 nm, and determine its high-resolution, native structure and complete subunit composition. The CPL architecture organizes maternal-effect proteins, ubiquitination machinery