Fig. 6. Gonadal homogenates, egg homogenate (E), and the purified major yolk protein (P) in P. depressus, subjected to (A) SDS-polyacrylamide gradient (5-20%) gel electrophoresis, stained with Coomassie Brilliant Blue (CBB), and (B) western blot analysis, immunostained with anti-MYP. Samples containing 10 µg of protein were applied to each lane. Numbers indicate the gonad stages. Molecular mass values on the left are indicated by the migration positions of marker proteins. In the western blots, higher molecular mass bands above the main bands are probably aggregations of MYP. Lower molecular mass bands below the main bands are cleavage products of MYP (e.g. Scott and Lennarz, 1989).