Fig. 4

Arrangement of mesoderm-derived organs and peripheral nerves in Pitx mutants and pharmacological treatment. In situ hybridization to Pitx mutants at N5 stage for Hand (a, b), Gata1/2/3 (c, d), Pdvegfr (e, f), and Scl (g, h). Blue arrowheads are Hatschek’s nephridium and black arrowheads are hematopoietic region. Black arrows are the HRD. i, j The arrangement of somites is marked by m-actin in N5 stage embryos. Longitudinal dashed lines indicate notochord, transversal dashed lines mark somite outlines. k, l Yellow arrows indicate peripheral nerves marked by acetylated α-tubulin. Quantification of the distance between a pair of somites (m), and the distance between a pair of peripheral nerves (n). Posterior five pairs of somites are used for measure in one embryo, and four pairs of peripheral nerves shown in the image are used for measure. Significance determined by t-test is indicated by asterisks: **P < 0.01. p–s The arrangement of posterior somites is marked by m-actin. Dashed lines mark outlines of newly budded somites. o The yellow ellipses indicate somites and red lines indicate peripheral nerves. no, notochord, nt, neural tube. All the embryos in above images are dorsal views. Numbers in the bottom right corner of a panel show the number of times the phenotype was seen, out of the total number of embryos from that genotype analyzed (a–l), or the phenotype was observed in the total number of embryos examined (p–s). A, anterior; P, posterior; L, left side; R; right side. Scale bars: 50 μm