Larger Image Figure 1: Wnt11b expression in the superficial mesoderm is required for asymmetric Pitx2c expression in the lateral plate mesoderm. (A–D) Wnt11b mRNA expression as determined by whole-mount in situ hybridization of staged embryos at stage (st.) 9.5 (A), st. 10.5 (B), st. 11.5 (C) and st. 13 (D). Specimens are shown in vegetal (A–D) or dorsal (D′) view. Please note that Wnt11b mRNA was present in the superficial mesoderm (sm; white arrowheads) on the dorsal side, as shown in bisected embryos in (A′) and (B′), while expression on the ventral side extended into deeper tissue (B′). Note also expression in the circumblastular collar (cbc) of involuting cells, as demonstrated in a histological section (D′). (E, F) Altered Pitx2c expression in Wnt11b-manipulated embryos. (E) Representative specimens. (F) Quantification of results. Green arrowheads, wild-type expression; red arrowheads, ectopic or absent expression. Dashed lines in (A, B, D′) indicate planes of section. *** Very highly significant (p<0.001). a = anterior, an = animal, d = dorsal, l = left, n = number, p = posterior, r = right, uninj. = uninjected, v = ventral, veg = vegetal. doi:10.1371/journal.pone.0073646.g001 Image published in: Walentek P et al. (2013) Image reproduced on Xenbase with permission of the publisher and the copyright holder. Creative Commons Attribution license Gene Synonyms Species Stage(s) Tissue wnt11b.L wnt-11, wnt11, Xwnt-11, xwnt11 X. laevis Sometime during NF stage 11.5 to NF stage 13 marginal zone mesoderm circumblastoporal collar involuted dorsal mesoderm involuted ventral mesoderm wnt11b.L wnt-11, wnt11, Xwnt-11, xwnt11 X. laevis Sometime during NF stage 9 to NF stage 10.5 mesoderm Image source: Published Experiment + Assay Source Phenotypes and Disease Xla Wt + wnt11b + NF31 (in situ hybridization) Fig. 1 E, F Expression Phenotype increased amount pitx2.L expression in right side Xla Wt + wnt11b MO + NF31 (in situ hybridization) Fig. 1 E, F Expression Phenotype absent pitx2.L expression in lateral plate mesoderm absent pitx2.L expression in left side Permanent Image Page Printer Friendly View XB-IMG-86980