Western-blot analysis of PIP2 proteins in microsomal protein fractions of wild-type and transgenic tobacco anthers. The PIP2 antibody detects two proteins in the wild type (WT; Bots et al., 2005). No proteins are detected in the anthers from transgenic plants (1, 2, 9, 10, 16, and 23). Sizes of the molecular mass markers are indicated at left.