Compounds affecting blood and lymph vessel development in Xenopus tadpoles. Control DMSO- (A-B) and compound-treated (C-J) Xenopus embryos were analyzed by whole-mount in situ hybridization for expression of the blood vascular marker gene apj at stage 35/36 and the lymphatic marker gene vegfr3 at stage 42. Panels of the embryonic blood vasculature (apj) are accompanied by close-up views illustrating ISV angiogenesis and VVN development in the embryonic trunk. The panels visualizing the developing lymphatic system (vegfr3) include close-ups of the head and midtrunk region (middle panels) for the ALSs and the ALHs, and enlargements (left panels) of the tail for PLVs. (A) Normal ISVs (arrowhead) and VVN (*). (B) Normal ALSs (arrow), ALHs (*), and PLVs (arrowheads). (C) Stunted ISVs (arrowhead), normal VVN (*). (D) Hypoplastic PLV (arrowheads), impaired ALS (arrow), and ALH (*) lymphatics. (E) Stunted ISVs (arrowhead), hypoplastic VVN (*). (F) Stunted ALS lymphatics (arrow), dysplastic ALH lymphatics (*), hypoplastic PLVs (arrowheads). (G) Normal ISVs (arrowhead), hyperplastic VVN. (H) Hypoplastic PLVs (arrowheads), impaired ALS (arrow), and ALH (*) lymphatics. (I) Stunted ISVs (arrowhead), hyperplastic VVN. (J) Complete lack of ALS (arrow), ALH (*) and tail lymphatics. Note that vegfr3 expression persists in the VVN (arrowhead). (K) Scheme of the blood vasculature (blue) of the stage 35/36 embryo. (L) Scheme of the lymphatic vasculature (orange) of the stage 42 embryo. 7-Cyclo indicates 7-cyclopentyl-5-(4-phenoxy)phenyl-7H-pyrrolo[2,3-d]pyrimidin-4-ylamine; Naphthalimide, 4-amino-1,8-naphthalimide; Naphthyridine, 7-chloro-4-hydroxy-2-phenyl-1,8-naphthyridine; PS; pronephric sinus; DPLV, dorsal posterior lymph vessel; and VPLV, ventral posterior lymph vessel.