Alkaline phosphatase activity and gene expression. (A1) Alkaline phosphatase histochemistry in the germinal layer, showing strong activity in the syncitial tegument. (A2) The signal in A1 was inverted and pseudo-colored in green, and combined with DAPI (blue) and phallodin (red) staining to show the distribution of the nuclei and muscle fibers, respectively. (B) Alkaline phosphatase histochemistry in an activated protoscolex, showing activity in the excretory system. (C) Semi-quantitative RT-PCR with serial ten-fold dilutions of cDNA from activated protoscoleces (PS act), non-activated protoscoleces (PS not act) and germinal layer (GL). The experiment was repeated three times with similar results. (D) WMISH of em-alp-2, showing strong expression in the germinal layer but not in the brood capsule bud. Abbreviations are as in Figure 2. Bars represent 20 μm.