Figure 2. Expression of planarian set1/mll family genes. Whole mount in situ hybridization showing the mRNA expression patterns of genes in the S. mediterranea set1/mll family. The lower worm of each pair was treated with 60 Gy of γ−irradiation three days prior to fixation. mes, mesenchyme; cg, cephalic ganglia; int, intestine. Animals are shown ventral side up with anterior to the left. Scale bars = 0.5 mm.