Figure 1.

Dissection of embryonic mouse SMGs and epithelial tissue and ex vivo organ culture system. Figure 1-A: After harvesting embryos at 13 days of development (left panel) the glands are dissected as follow: the head of the embryo (left panel) is removed at the neck and ~1 mm slice of the inferior mandible is removed (middle panel), the posterior half of the slice with the brain stem is removed (bar), and the tongue is separated from the mandible with the SMGs attached (right panel). The two SMGs, positioned at the base of the tongue, are finally separated with fine forceps. Scale bar = 1 mm. Figure 1-B shows the variation of SMGs morphologies at E13 depending on the time of mating. Earlier glands, shown in the left and middle panels, are suitable for epithelial-mesenchyme dissections; glands at late E13 have undergone a lot of branching and the epithelium is difficult to separate intact from the mesenchyme. After dissection, SMGs are placed in media and the epithelial rudiments separated from the mesenchyme as shown in Figure 1-C. The diagram in Figure 1-D shows the culture set up; epithelial rudiments are plated in a drop of laminin-111 substrate on top of a filter, floating on 200μl of medium.