Fig. 7. INTS13 is required for embryonic development and ciliogenesis in Xenopus laevis.

a Western blot showing that the INTS13 MO was able to deplete INTS13 protein in Xenopus embryos and molecular weight markers shown are in kilodaltons. b In comparison to control embryos, morpholino (MO)-mediated knock down of INTS13 in Xenopus leads to severe developmental defects including a small head, big belly, short and down curved body axes, cardiac edema and massive developmental delay. Scale bar represents 500 μM. c In situ hybridization using a specific probe for the multi-ciliated cell (MCC) marker ccdc9 shows a reduction in ccdc9 expression in MCC of morphants compared to control embryos. d Whole mount antibody staining for acetylated α-tubulin shows a punctate pattern similar to ccdc9. The puncta have a more condensed and stronger signal in control embryos. A higher magnification view of the MCC shows marked reduction in cilia compared to controls. b–d n > 60 control or morphants embryos were used for three sets of independent injections. Scale bar represents 50 μM. e Low magnification SEM imaging of Xenopus MCC at embryonic stage 28. MCCs of a control embryo possess multiple, long cilia, whereas the morphant MCCs display fewer cilia per cell which appear to be disorganized. f High magnification SEM imaging of Xenopus MCC at embryonic stage 28. Ciliary length seems unperturbed in morphant embryos, while the average number of cilia on individual MCCs is clearly reduced by INTS13 knockdown. The average MCC in morphants have less than half of the number of cilia per cell compared to control, as shown in the bar graph. g The ultrastructure of the cilia in morphants appears to show a normal 9 + 2 structure as imaged by TEM. e, f, n = 3 control or morphant tadpoles were processed for SEM and n > 30 multiciliated cells were examined for the number of cilia present. g n = 5 cilia were examined by TEM. *p  < 0.05, **p < 0.01, ***p <  0.001, ****p < 0.0001, respectively. Source data are provided as a Source Data file.