Fig. 1

Nppa and Nppb play redundant roles during early cardiac development. (A) Schematic of the zebrafish nppb and nppa gene cluster (on chromosome 8) and respective nppb CRISPR/Cas9 (base pair 239) and nppa TALEN cleavage sites (base pair 54). Sanger sequencing show three alleles of nppa and nppb genes identified following genome editing (nppa^uq19ks, nppb^uq20ks and nppb^uq21ks). (B) Schematics of Nppa and Nppb wild-type and mutant proteins. Numbers indicate predicted amino acid positions. (C) In situ hybridisation for nppa and nppb on sibling and double mutant embryos at 48 hpf demonstrate overtly wild-type morphology of double mutant hearts. nppa gene expression is unaltered in double mutants, whereas nppb appears decreased in double mutants. (D-G) Lateral bright-field images of representative 72 h post-fertilisation (hpf) sibling and double mutant embryos. Black arrow indicates the pericardial oedema observed in double mutants. (H) Pie charts illustrate the penetrance and expressivity of the phenotype at 48 hpf and 72 hpf.