Figure 1.

Figure 1.

A novel kif2a knock-out zebrafish model shows that kif2a is not indispensable for survival and mutations do not result in gross morphologic abnormalities. a, Linear representation of the human kinesin 2A polypeptide with highlighted four de novo MCD-associated mutations (indicated in red-pink) located in or near the ATP-binding region (indicated in green). Kinesin motor domain, coiled coil, and globular domains (UniProtKB-O00139) are highlighted. Multiple sequence alignment shows the level of conservation of the ATP binding region (indicated in dark turquoise) of human, mouse, and zebrafish. b, Localization of 4-nucleotide deletion (CCAG) in the globular region of Kif2a and electropherogram of kif2a^+/+ larvae, confirming the presence of the mutation in homozygotes. c, Kaplan–Meier survival rate curves of kif2a^+/+ (n = 5), kif2a^+/− (n = 21), and kif2a^−/− (n = 10) larvae. Larvae were obtained by the mating of heterozygous adults. Surviving larvae were counted every 24 h until 30 dpf. d, Lateral bright-field images representing normal macroscopic morphology of 3 and 5 dpf kif2a^+/+ and kif2a^−/− larvae. Scale bar, 1 mm. The design of the CRISPR/Cas9 kif2a zebrafish knock-out line is illustrated in Extended Data Figure 1-1. qPCR analysis of kif2c expression levels showed no upregulation of kif2c during development in kif2a^−/− larvae (Extended Data Fig. 1-1).