Overview

• The University of Osaka team reports that Cfap91 knockout male mice form defective sperm flagella and are infertile.
• Rescue experiments show CFAP91 interacts with known radial spoke components and functions as a scaffold for their assembly.
• Proximity labeling in mature sperm identifies EFCAB5 as a CFAP91-proximal protein that helps regulate specialized sperm movement.
• The work maps protein interactions using genetic knockout, re-expression, and proximity-labeling methods to probe flagellar architecture.
• The findings suggest candidates for future infertility diagnostics, though confirmation in human samples is still needed.