Fig. 1

Cfap298ΔΔS mutants display left–right laterality defects. (A) Generation of the Cfap298ΔΔS mutant allele by targeting exon 4 of the Cfap298 gene using CRISPR/Cas9 gene targeting. Guide recognition sequence within the exon 4 sequence is in red on the wild-type sequence. The Cfap298ΔΔS mutation consists of a 6 base deletion and a base substitution of T→C, resulting in the removal of two amino acids at positions 161 an 162, and a missense mutation of P163S (gray shading). (B) AlphaFold predicted structures of CFAP298 and CFAP298ΔΔS proteins in the region of the ΔΔS mutation. Y161 and D162 are labeled in wild-type CFAP298, and S161 is labeled on CFAP298ΔΔS (Abramson et al., 2024). (C) Whole-embryo images of E14.5 wild-type and Cfap298ΔΔS/ΔΔS embryos. Scale bar: 1 mm. (D) Viability distribution of wild-type, heterozygous and homozygous mutant embryos at E9.5 (n=17), E13.5 (n=15), E14.5 (n=33), E15.5 (n=21) and E16.5 (n=6). (E) Representative images of body cavities showing heart, lungs and stomach positions from Cfap298ΔΔS/+ and Cfap298ΔΔS/ΔΔS E14.5 embryos. Scale bars: 1 mm. (F) Quantification of situs solitus, situs inversus and heterotaxy from wild-type (n=21), Cfap298ΔΔS/+ (n=46) and Cfap298ΔΔS/ΔΔS (n=18) embryos from E13.5–E15.5 stages. (G) Representative images of heart, lung and stomach from E14.5 Cfap298ΔΔS/+ and Cfap298ΔΔS/ΔΔS embryos displaying with situs solitus (normal), situs inversus (reversed) and heterotaxy phenotypes. Hearts and stomachs are outlined. Individual lung lobes are outlined and labeled with their position on either left (L) or right (R). Atria (red asterisks) and ventricle (black asterisk) are indicated in the heart with heterotaxy. Scale bars: 1 mm.