Western blot of zebrafish oocyte or embryo extracts at the indicated developmental stages probed by anti-γ-tubulin antibodies (GTU-88 or TU-30). Molecular weight standards (in kilodaltons) are shown at left. Each sample lane was loaded with 0.8 mg of protein (wet weight equivalent). (A) Original 40,000 × g supernatant probed by TU-30. (B) Original 40,000 × g supernatant probed by GTU-88. Arrowhead indicates γ-tubulin breakdown product. (C) Original 40,000 × g pellet probed by TU-30. (D) Original 40,000 × g pellet probed by GTU-88. Lane 1: Fully grown oocyte. Lane 2: one to four cells. Lane 3: eight to sixty-four cells. Lane 4: 64 to 128 cells. Lane 5: Midblastula (> 1,000 cells). Lane 6: Gastrula. Lane 7: Pharyngula. Reprinted with permission .