In situ structure of the mouse sperm central apparatus reveals mechanistic insights into asthenozoospermia.

ABSTRACT: The central apparatus (CA) within the sperm axoneme is vital for sperm motility, yet its molecular architecture and functional mechanisms remain incompletely understood. Combining cryo-electron tomography and AlphaFold2, we resolved the in-cell structure of mouse sperm CA at a subnanometer resolution and built a near-complete atomic model. Our analysis identified 39 CA-associated proteins, including eight previously unreported components. By presenting the full-length structures of CFAP47 and HYDIN, we elucidate their molecular roles in tethering the C1 and C2 microtubules within the CA. Specifically, HYDIN forms a semicircular chain that encircles C1 and C2, with its N-terminal half driving the C1-C2 connection and its C-terminal half providing axial support in C2. CFAP47, the core struct

SUBMITTER: Zhu Y 

PROVIDER: S-EPMC12297659 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature