Folate and retinoic acid signaling. A) Schematic of the experimental design for B–G (2 experiments and n=20). B–C) Representative frontal views of faces at stage 42–43 treated with DMSO (B) or folinic acid (C) RAR inhibitor (D), or RAR inhibitor and folinic acid (E). F) Schematic of the facial dimensions measured. G) Bar graphs summarizing quantification of facial dimensions corresponding to B–E. H) Schematic of experimental design for I–M (2 experiments, n=20). I–L). Representative frontal views of faces at stage 42 treated with DMSO (I) or MTX (J) RAR inhibitor (K), or RAR inhibitor and MTX (L). M) Bar graphs summarizing quantification of facial dimensions corresponding to I–L. Mouth is outlined with red dots in all frontal views and asterisks designate statistical significance with all p values < 0.001. All images are at the same magnification, scale bar =175 μm. Abbreviations: C=control, R=RAR inhibitor, F=folinic acid, M=methotrexate.