Figure 5.

Representative snapshots and phenotypic analysis of 50 hpf zebrafish larvae with unfloxed (A–D) or floxed (E–H) integrated RNAi transgene. (A–D) In the absence of iCRE, the transgene remains unfloxed triggering BFP expression and not inducing any significant developmental defect in the analyzed embryos. (E–H) In the presence of iCRE, BFP is excised and mKate expressed along with anti-smn1 miRNAs, triggering SMA-hallmarks such as motoneuron defects. Images represent standard deviation projections from confocal z-stack acquisitions using three channels (merged) to detect eGFP (green, motoneurons), tagBFP (blue, ubiquitous expression) and mKate (red, ubiquitous expression). White arrows indicate abnormal CaP motoneurons. (I) Number of ventral motoneuron (CaP) abnormalities observed per side of 50 hpf larvae. ubi-floxed tg(loxSMN) animals were also injected with hsa-SMN1 mRNA to test the specificity of the observed phenotype. (J) Animal size comparison at 52 hpf. (K) Survival assay (Kaplan Meier) for the different lines and conditions tested. Means of 20 larvae ± SEM.