Figure S1.

Recombinant WT- and E130A-Calaxin can bind to a Calaxin-deficient outer arm dynein (OAD).

Immunofluorescence of sperm flagella from WT, calaxin^−/−, and armc4^−/− zebrafish supplemented with recombinant proteins. Scale bar, 10 μm. (A) Sperm flagella with BSA as a control. Compared with WT, calaxin^−/− lacked OAD Dnah8 in the distal region (arrowheads) and completely lost Calaxin (asterisks) as in Fig 1C. Armc4^−/− completely lacked both Dnah8 and Armc4 (asterisks). (B) Sperm flagella with BSA and WT-Calaxin. Calaxin localized to the proximal Dnah8(+) region in calaxin^−/− (arrowheads), but it did not bind to armc4^−/− sperm flagella (asterisks). (C) Sperm flagella with BSA and E130A-Calaxin. E130A-Calaxin showed an identical localization pattern as WT-Calaxin in (B). It colocalized with Dnah8 in calaxin^−/− (arrowheads), but it did not localize to armc4^−/− sperm flagella (asterisks).