Fig. 5

a Two loss of function alleles of lrif1 were generated in zebrafish by CRISPR/Cas9 injections. b Endogenous spatial-temporal expression pattern of lrif1 in zebrafish embryos as determined by qPCR and WISH. n = 3 biological samples (qPCR), 3 independent experiments with at least 20 embryos each (WISH). c Maternal zygotic (MZ) lrif1^lof embryos lack lrif1 mRNA suggestive of total nonsense-mediated decay. n = 3 biological samples. P values were calculated by 2-tailed unpaired Student’s t test. d, e Axial skeletal patterning defects in adult fish. Phenotypes include loss of a rib (filled arrow), loss of a supraneural vertebra (arrowhead) and loss of a caudal vertebra (open arrow). P values were calculated by the Kruskal-Wallis test followed by Dunn’s Multiple Comparison Test. f qPCR shows that hox derepression is detected in unfertilized oocytes from both +/− and −/− females. P values were calculated by 2-tailed unpaired Student’s t test. Inset shows expression of lrif1 in Stage I and II oocytes. Scale bars = 200 µm. n = 3 biological samples (qPCR), 5 ovaries of adult fish (WISH). g Model of Smchd1/Lrif1-driven transgenerational inheritance for skeletal patterning. Smchd1/ Lrif1 sets up an epigenetic state during oogenesis to ensure correct expression of hox genes during embryogenesis which in turn patterns the vertebrae. *p < 0.05, **p < 0.01, ***p < 0.001. All data are presented as mean values ± SD.