Figure 3: Missense mutation in CFTR affects proliferation of germ and Sertoli cells. (a) Endogenous CFTR protein expression in four types of cells. Loading control was β-tubulin. C band: mature CFTR; B band: immature CFTR. (b) Schematic illustration of targeting strategy for generating Cftr p.G965D knock-in cell lines. Mutated nucleotides are shown in red. The nucleotide in blue indicates a mutation that does not affect the amino acid sequence in the protospacer adjacent motif. (c) Proliferation of wild-type (WT) and point mutant GC2 cell lines. (d) Proliferation of wild-type and point mutant TM4 cell lines. Cftr p.G965D mutation affected GC2 cell proliferation and slowed TM4 cell growth. CFTR: cystic fibrosis transmembrane conductance regulator; gRNA: guide RNA; Cas9: CRISPR-associated protein 9; CRISPR: clustered regularly interspaced short palindromic repeats; OD: optical density.