Fig. 6: The temporal roles of gastrulation stage BMP signaling pathway in regulating left–right asymmetry.

a Experimental strategy of ex vivo culture and analysis of embryos following chemical inhibition of BMP activity for 3, 6, 9, 12, and 15 h beginning on E7.0. b Whole-mount RNAscope analysis of embryos after 30 h of ex vivo culture, showing the expression of Nodal in the lateral mesoderm and the node (ventral view). The frequency of left-sided expression of Nodal is shown for Group A (untreated control) and Group B (3 h treatment), and the frequency of abnormal (bilateral) expression of Nodal is shown for Groups C (6 h treatment), D (9 h treatment), E (12 h treatment), and F (15 h treatment). c Table showing the pattern of Nodal expression in the cultured embryos collected at 30 h in vitro (equivalent to E8.25). A chi-squared test was performed to determine the statistical significance. d Whole-mount in situ hybridization of Dand5/Cerl2 in cultured embryos from indicated experimental groups. Three biologically independent samples for each group were examined for consistency of gene expression pattern. e Experimental strategy of ex vivo culture and analysis of embryos following chemical inhibition of BMP activity for 6 h beginning at E7.25 (Group G and H), E7.5 (Group I and J), and E7.75 (Group K and L) stages. f Whole-mount in situ hybridization of Lefty2 after ex vivo culture (equivalent to E8.25), showing the expression of Lefty2 in the lateral mesoderm (ventral view). The frequency and embryo number of annotated patterns of Lefty2 are shown for each group. g Table showing the pattern of Lefty2 expression in the cultured embryos collected at equivalent E8.25 stages. A chi-squared test was performed to determine the statistical significance. h Whole-mount in situ hybridization of Dand5/Cerl2 in cultured embryos from indicated experimental groups. Three biologically independent samples for each group were examined for consistency of gene expression pattern.