Figure 1

klhl40 is essential for vertebrate skeletal muscle development. (A) Schematic diagram depicting the position of CRISPR-mediated mutant alleles and truncated proteins on the Kelch protein domain in klhl40abwg200 and klhl40bbwg202 knockout zebrafish. CRISPR-induced mutations in klhl40abwg200 and klhl40bbwg202 knockout zebrafish result in premature termination codons in BTB and BACK domain coding exons, respectively. (B) Sanger sequencing pherograms for control and klhl40a bwg200 and klhl40b bwg202 mutant zebrafish with an insertion of A in klhl40abwg200 and an insertion of C in klhl40bbwg202 coding regions. (C) Lateral view of the juvenile and adult zebrafish. klhl40a mutant zebrafish develop leaner bodies from transition to juvenile (1.5 months old) to the onset of the adult stage (3 months old) and exhibit reduced body length and body diameter. No obvious skeletal muscle phenotype is observed in the klhl40b allele compared to control (+/+) siblings. klhl40a/ klhl40b double mutant fish exhibit similar skeletal phenotype as observed in the klhl40a allele. (D) Endurance swimming behavior of klhl40a allele at juvenile state (1.5 months) and adult stage (3 months) (n=7–8). (E) The Kaplan-Meier survival curve of the different zebrafish groups was analyzed for 20 months (n=20 in each group). Data are mean ± S.E.M (unpaired t-test, parametric) for each experiment. Note: the survival curve of klhl40b mutant fish overlaps with the control fish.