|
Activation and repression of snai1b modulates delamination for trabeculation. a Experimental plan for the myocardial Tol2-CRISPR activation/interference (CRISPRa/i) system. Tol2 transposon plasmids were injected in one-cell stage embryos to induce mosaic activation or repression of snai1b among cardiomyocytes (CMs). In total, four sgRNAs that target different promoter regions of snai1b were used. Two scramble sgRNAs were used as control. Right panels show the mechanism of activation (VPR) and repression (KRAB). For system validation, see Supplementary Fig. 8. Partially created in BioRender. Wang, J. (2025) https://BioRender.com/ep5rh7k. b–d Under ISO treatment, the majority of control (58.3%) and snai1b-repressed (56.7%) CMs remained in the compact layer at 4 dpf (96 hpf). Activation of snai1b led to significantly more delaminated (see Supplementary Fig. 9b) and trabecular CMs per heart (c), where 51.6% of total snai1b-activated CMs form trabeculae, compared to 25.0% of control and 6.7% of snai1b-repressed CMs (d). On the other hand, repression of snai1b resulted in 36.7% of CMs undergoing apical delamination. For representative images of CRISPRa/i-injected hearts without ISO, see Supplementary Fig. 9a. All values in (c) are displayed with mean and standard error of mean (SEM). p-value is displayed for each comparison. Number of hearts analyzed: Control-ISO = 7, Repression-ISO = 7, Activation-ISO = 11. Ordinary one-way ANOVA followed by Holm-Šídák’s multiple comparisons test on the means was applied to determine statistical significance. Source data are provided as a Source Data file. Anatomic labels: V ventricle, Comp compact layer, Trab trabeculae.
|
