| |
Figure 7. Retinol binding protein 1 knockdown affects expression of genes involved in all-trans RA signaling. A, Upon retinol binding protein 1 (Rbp1) morpholino oligonucleotide (MO) injection, expression of nosip was reduced in the eye vesicle at stage 23 (black arrowhead). Lateral views and a statistical evaluation are given. Transversal sections support a reduction in nosip after Rbp1 knockdown (black arrowhead). B, Expression of cyp26a1 was reduced in the eye (red arrowhead) and neural crest cells (white arrowhead) upon Rbp1 MO injection at stage 30. A statistical evaluation of embryos with reduced cyp26a1 expression is given. The reduction in the lens upon Rbp1 knockdown was shown on sections (red arrowhead). C, At stage 23, pitx2 was reduced in the NCC-derived periocular mesenchyme upon Rbp1 MO injection (black arrowhead). A statistical analysis is given. D, Rbp1 MO injection resulted in microphthalmia (white arrowheads) at stage 43, which was significantly rescued by co-injecting 0.5 ng pitx2 RNA. A statistical evaluation is given. Scale bars: dorsal, 500 μm; lateral, 500 μm; and detail, 150 μm. E, Calculation of the eye area (red dotted circles) at stage 43. Single embryos from one experiment with a representative phenotype were evaluated and are shown in a statistical quantification. Co-injection of Rbp1 MO and pitx2 RNA significantly rescued the eye phenotype. Scale bar: 150 μm. F, Comparison of the head size of injected (blue line) and uninjected (black line) sides upon Rbp1 MO injection in Xenopus embryos. The reduction in the head size upon Rbp1 MO injection was significantly rescued by co-injecting pitx2 RNA. A statistical evaluation is given. Scale bar: 500 μm. Abbreviations: inj., injected; MO, morpholino oligonucleotide; N, number of evaluated embryos in total; n, number of independent experiments; Rbp1, retinol binding protein 1; uninj., uninjected. Statistics: Error bars visualize SEM; *P ≤ .05; **P ≤ .01. P values are calculated by a nonparametric, one-tailed Mann-Whitney rank sum test |
