Fig. 9.

Co-localization of VWF and P-selectin in a MK from the spleen of an untreated Gata1^low mouse. Representative sections from Gata1^low mice spleen were double stained for P-selectin (large gold particles) and VWF (small gold particles). Because the Gata1 mutation blocks maturation (Centurione et al. 2004), only stages I/II MKs were available for analysis. Red arrows and arrowheads point to structures containing the proteins, while the white ones point to the structure itself. In a), cells are characterized by a large nucleus with several nucleoli, with a cytoplasm that contains ribosomes and well developed RER. In b,c,d), P-selectin and VWF co-localize in the cytoplasm in the immature MKs of Gata1^low mice. Both proteins were found in proximity to the DMS (whole arrows) and in the vacuoles representing degenerated granules (arrowheads). Original magnifications: a) × 4,400; b,c,d) × 30,000.