Fig 3

fn1b expression levels correlate with the severity of the natter/fn1a^tl43c and fn1a^bns692 mutant cardiac phenotype.

(A)fn1b mRNA levels were analysed by RT-qPCR in individual 72 hpf protruding mouth stage larvae collected from single pair natter/fn1a^tl43c and fn1a^bns692 heterozygous intercrosses. Each data point represents an individual larva. Expression is relative to homozygous WT siblings in each clutch. Eight clutches were examined for each allele from experiments described in S2 and S4 Figs. (B, C)In situ hybridisation for fn1b was performed on 72 hpf larvae from two single pair fn1a^bns692 heterozygous intercrosses. The proportion of larvae matching the image shown is indicated in the top right corner of each image. (B) Lateral views with anterior to the left. (C) Ventral views with anterior to the top. (D) Quantification of the 100 hpf cardiac phenotype in mutant larvae injected with 350 pg fn1b mRNA and uninjected controls from five single pair fn1a^bns692 mutant incrosses. (E) Quantification of the 100 hpf cardiac phenotype in fn1a^bns692; fn1b^ya14Tg mutants and siblings from three single pair fn1a^bns692; fn1b^ya14Tg double heterozygous intercrosses. The numbers on each bar in (D) and (E) indicate the total number of larvae assessed. For (A), p-values were calculated by one-way ANOVA with Tukey’s post-hoc test for multiple comparisons; for (D), p-values were calculated with chi-squared tests; and for (E), p-values were calculated by Fisher’s exact test with Bonferroni correction for multiple comparisons. Scale bars, 1 mm in (B) and 100 µm in (C).