A method to monitor the recruitment of centriole components in vivo. (A) Schematic of the mating scheme used to monitor centriolar recruitment of GFP fusions. (B) Imaging and quantification flowchart. (C) A pair of representative images and schematic of the method used to measure the GFP intensity coincident with the RFP-labeled sperm centrioles. The regions corresponding to the two sperm centrioles in the low magnification images are indicated (white dashed boxes). A 5 × 5 pixel box (red) and a larger 7 × 7 pixel box (blue) were drawn around the peak RFP signal for each sperm centriole and GFP intensity was quantified as outlined. (D) Timeline of events between fertilization and onset of the first embryonic cytokinesis. Times for each event (n > 5 embryos) are in seconds relative to cytokinesis onset (t = 0) ± standard deviation. Schematics illustrate intermediates in centriole assembly based on ultrastructural work (Pelletier et al., 2006). After fertilization, the sperm-derived centrioles separate and by early S phase (∼−950 s), a small central tube ∼60 nm in length and 40 nm in diameter is present adjacent and perpendicular to each sperm-derived centriole. By early prophase, the central tube is ∼110 nm in length and 65 nm in diameter. Centriolar microtubules assemble during the second half of mitotic prophase (−450 to −250 s), and their assembly is complete by metaphase (−150 s).