Fig. 1. Identification of a novel sperm PLC. (A) Immunoblot analysis of heparin-eluted soluble extracts of brain, kidney, liver and sperm (lanes B, K, L, S; 50 µg/lane) from mouse, boar and hamster, using antibody raised to the novel sperm PLC. Molecular weight markers in kDa, on the right. (B) Immunoblot of heparin-eluted soluble sperm proteins fractionated by gel filtration column chromatography on Sephacryl S-200 column. The underlined 150 kDa and 29 kDa indicate elution positions of gel filtration standards alcohol dehydrogenase and carbonic anhydrase, respectively. Shown below is the corresponding Ca²⁺ release activity of column fractions B, D and F assayed fluorometrically in sea urchin egg homogenates. Scale bars indicate time (seconds) and relative fluorescence units (RFU) (Jones et al., 1998b). Arrows indicate time of addition.