Fig. 2.
Expression of sAC in Montipora capitata sperm. (A) Western blot of the sAC protein in sperm from three different individuals (lanes 1 to 3) shows high expression of two isoforms (sACFL, sAC110) and low expression of two isoforms (sAC55, sAC45). (Inset) High exposure of same blot. Approximate size (kDa) of each protein is indicated on the left. (B) Western blot of somatic tissues from four M. capitata adults (lanes A to D) show expression of a single sAC isoform (sAC45). (C) Diagram of the architecture of coral sperm, identified by ref. 46. The head houses the nuclei and the surrounding acrosome compartment. The flagellum contains the axoneme formed from a 9 + 2 microtubule bundle and, immediately posterior to the head, a mitochondria-rich midpiece. (D) Brightfield image of sperm. (E) Corresponding fluorescence micrograph showing localization of sAC (green), DNA (blue), and flagella (magenta; stained with anti-β-tubulin antibodies). (F) Corresponding image of coral sAC expression alone. (G) Brightfield image of a sperm cell with the flagellum extended. (H) Corresponding fluorescence micrograph highlighting coral sAC expression along the length of the flagellum. Arrowheads indicate the midpiece of the flagellum containing the mitochondrial sheath, and asterisks indicate the flagellum.