Fig. 5.

In utero exposure of mouse embryos to excess of RA upregulates endothelial LYVE-1 expression in the anterior cardinal veins and jugular lymph sacs. Immunohistochemical analysis of paraffin sections from ED 11.5 mouse embryos for LYVE-1 revealed that the endothelial cells of the anterior cardinal veins and of the forming lymph sacs up-regulated the expression of LYVE-1 after in utero exposure to an excess of RA (d–f and j), as compared with control embryos (a, b, arrowheads, c and j). Treatment with the RAR-α antagonist Ro 41-5253 decreased LYVE-1 expression (g–j). The jugular lymph sac area was enlarged after RA treatment as compared to controls (k). b, c, e, f, h and i are sections of embryos from two independent pregnant mice each. a, d, g Scale bars = 100 μm; b, e, h, c, f, i scale bars = 50 μm. jls = Jugular lymph sac; nt = neural tube; v = cardinal vein. Data are expressed as mean values + SD (n = 4). ** p < 0.01.