Fig. 6

A Schematic illustration of genetic sensitizing by nek9 in an ELC phospho-deficient genetic background. The concept is based on the progressive amplification of a response by functionally coupled factors. B Penetrance of NEK9 KD in zebrafish embryos at 72 hpf. Different concentrations of antisense oligonucleotides against zebrafish nek9 were injected in a genetic wild-type background (KD NEK9: knockdown of NEK9 resulting in a significant heart failure phenotype; LD NEK9: low-dose knockdown showing no phenotypical effect). Data are mean ± SD (Ctrl, n = 517; LD NEK9, n = 162; KD NEK9, n = 461 fish embryos out of 4 (Ctrl), 3 (LD NEK9) and 5 (KD NEK9) experiments). For statistical analysis a mixed effect model followed by Bonferroni’s multiple comparisons test was used. **P < 0.01 shown for the corresponding embryos injected with Ctrl oligonucleotides. C Validation of NEK9 KD or LD NEK9 by immunoblot (IB). D Lateral view of heterozygous lazy susan (laz^m647/+) embryo hearts 72 hpf injected with control oligonucleotides or low-dose antisense oligonucleotides against zebrafish ilk (LD ILK) or nek9 (LD NEK9). E Genotype-phenotype-association of laz^m647 zebrafish injected with control oligonucleotides, LD ILK or LD NEK9. Individual genotyping was performed after blinded phenotyping at 72 hpf. Data are mean ± SD (Ctrl: laz^+/+n = 41, laz^m647/+n = 81; LD ILK: laz^+/+n = 21, laz^m647/+n = 46; LD NEK9: laz^+/+n = 49, laz^m647/+n = 97 fish embryos out of 3 experiments). *P < 0.05, **P < 0.01 by the analysis of two-tailed paired Student’s t-test. F Fractional shortening (FS) of genetic sensitized lazy susan (laz^m647) embryos. After analyzing FS, individual genotyping was performed and associated with the phenotype. Data are mean ± SD (Ctrl: laz^+/+n = 41, laz^m647/+n = 82; LD ILK: laz^+/+n = 21, laz^m647/+n = 46; LD NEK9: laz^+/+n = 49, laz^m647/+n = 97 fish embryos out of 3 experiments). ***P < 0.001 by the analysis of ordinary one-way ANOVA followed by Bonferroni’s multiple comparisons test.