This research paper describes the atomistic-resolution structure of the mouse cytoplasmic lattice (CPL), a massive protein storage organelle essential for mammalian reproduction. Using single-particle cryo-electron microscopy, scientists determined that the CPL is a 4-MDa repeating unit featuring a tripartite architecture of an external framework, linkers, and a core. The study reveals how this lattice sequesters and inhibits vital maternal factors, such as the epigenetic regulator UHRF1, GTP-bound tubulin, and ubiquitin ligase components. These stored proteins are held in a poised but inactive state to ensure their timely release during the critical oocyte-to-embryo transition. By providing a molecular blueprint of the CPL, the authors establish a framework for diagnosing and treating female infertility caused by genetic defects. Mapping over 300 clinical variants onto this structure further confirms that lattice integrity is indispensable for early embryonic development.

References:

• Chi P, Wang X, Li J, et al. Structure of the mouse cytoplasmic lattice[J]. Nature, 2026: 1-3.