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Figure 3
(A) DMT structure of WT zebrafish sperm flagella. A-tub and B-tub: A- and B-tubule of DMT, respectively. OAD: outer arm dynein, IAD: inner arm dynein, RS: radial spoke. Upper left: side view, upper right: base-to-tip view, lower left: bottom view, and lower right: back view of RSs. Black arrowheads indicate the spoke heads of RS1 and RS2. White arrowhead indicates the spoke head of RS3. Red arrowheads indicate the RS3 structures which are not found in the RS3 in human respiratory cilia. (B) Diagram of DMT structure. N-DRC: nexin-dynein regulatory complex. f IC/LC: IAD-f intermediate chain and light chain complex. (C) Back view of RSs in human respiratory cilia (EMD-5950; Lin et al., 2014). (D–E) DMT structures of calaxin-/- sperm flagella. Structural classification sorted the subtomograms into two classes: (D) OAD+ class (70.7%, 6122 particles) and (E) OAD- class (29.3%, 2535 particles). (F) DMT structure of armc4-/- sperm flagella. Green: OAD, pale red: IAD-f, orange: IAD-a, yellow: IAD-b, light-green: IAD-c, cyan: IAD-e, indigo: IAD-g, violet: IAD-d, and blue: RSs. Red circles indicate the loss of OAD.
Cryo-ET structures of DMTs in WT and mutant sperm flagella.