Cryo-electron microscopy unravels microtubule inner protein networks reinforcing mammalian sperm flagella

ABSTRACT: To find and fuse with the egg, mammalian sperm must complete an arduous voyage through the female reproductive tract. This odyssey is powered by the sperm tail, a specialized motile cilium. Mammalian sperm tails are reinforced at the molecular scale with sperm-specific microtubule inner proteins (sperm-MIPs), but the identities of these sperm-MIPs are unknown. Here, we report high-resolution cryo-electron microscopy structures of bovine sperm doublet microtubules (DMTs), allowing us to identify many sperm-MIPs. We also resolve structures of singlet MTs in the endpiece, revealing MIPs shared between singlet and doublet MTs. We demonstrate that at least two sperm-MIPs bind and stabilize MTs in vitro. Our structures shed light on ciliary diversity across cell types and provide structural frameworks for understanding molecular underpinnings of male infertility

INSTRUMENT(S):

ORGANISM(S): Bos Taurus (bovine)

TISSUE(S): Spermatozoon

SUBMITTER: Riccardo Zenezini Chiozzi  

LAB HEAD: Albert Heck

PROVIDER: PXD035941 | Pride | 2023-06-20

REPOSITORIES: Pride