Fig. 5.

Isl1 lineage map of the thymus and thymus vasculature in control and Fn1^flox/−; Isl1^Cre mutants. Sections through the thymus isolated from E16.5 embryos. (A-A′) Section from Isl1^Cre;ROSA^mTmG embryo. The bulk of the thymus and thymus endothelial cells (Pecam1, blue, arrowhead in A′) are derived from Is1⁺ cells. Pericytes (NG2, red, arrows) in the thymus are not of the Isl1⁺ lineage. Thymi from control (B–C) and Fn1^flox/−; Isl1^Cre mutant embryos (D–E) were stained to detect endothelial cells (Pecam1, green), pericytes (PDGFRβ, red, arrows) and nuclei (DAPI, blue). 40 × (B–B′; D–D′) and 63 × (C–C′, E–E′) images are shown. All scale bars are 100 µm, except in C–C′ and E–E′, where they are 10 µm.