Fig. 3: WASP deficiency results in overexpression of splicing factors.

a Representative TEM images of 70-nm sections of WAS-iMPs and cWAS-iMPs collected under identical conditions. Bar = 1 μm in the large panels; Bar = 0.5 μm in the insets. IGC: interchromatin granule cluster (nuclear speckles). Number of cells analyzed: n = 7 (WAS-iMP1), n = 4 (cWAS-iMP1). b Representative maximum projection confocal images and image-based quantitative analysis of the nuclear speckle marker SRSF2 in WAS iMP1s, cWAS iMP1s, WT iMPs and KO-iMPs (three clones). The mean fluorescence intensity (MFI) of SRSF2 signal per nucleus was measured in the 2D images in cWAS iMP1s (n = 15), WAS iMP1s (n = 22), WT iMPs (n = 49), C52 KO-iMPs (n = 53), C152 KO-iMPs (n = 59), and C157 KO-iMPs (n = 54). For the 3D analysis of the MFI and volume of nuclear speckles, SRSF2 speckles were segmented and quantitated using the Avizo software (see “Methods”). Number of particles analyzed: n = 217 (cWAS iMP1s), n = 379 (WAS iMP1s), n = 129 (WT iMPs), n = 64 (C52 KO-iMPs), n = 51 (C152 KO-iMPs), n = 62 (C157 KO-iMPs). Data are normalized by the corresponding wild-type and shown as mean ± SEM. Comparisons were performed with two-sided Student’s t test, or Mann–Whitney test if data are not normally distributed, *P = 0.0173, ***P = 0.001, ****P < 0.0001. Bar = 5 μm. Source data are provided as a Source Data file. c PCA of RNA-seq data of WAS-iMPs, cWAS-iMPs derived from two patients, and wild-type CB-MP. d Heatmap of samples shown in C based on upregulated SFs. e PCA of RNA-seq data of WT iMPs and WASP-KO-iMPs. f Heatmap of upregulated SFs in WASP-KO-iMPs shown in (e). g Volcano plot of mass spectrometry of WT and WASP-KO-iMP samples. Parametric test with Benjamini–Hochberg correction. h Heatmap of upregulated SFs in WASP-KO-iMPs shown in (g). i GO analysis of upregulated proteins in WASP-KO-iMPs.