rapgef1-knockdown reduced locomotor capacity and led to irregular motor neuron axon
Both E2I2-MO and ATG-MO exerted negative influences on the locomotor capacity and motor neuron axon of zebrafish. We observed obvious reduction in the movement parameters of rapgef1a -knockdown zebrafish larvae in the rapgef1a -knockdown group when compared to controls, including the moving velocity and distance (Figure 5 (A) and (B)). To evaluate the deleterious effect of human mutant RAPGEF1transcript, we again co-injected the E2I2-MO and human RAPGEF1transcripts with and without the aforementioned patient mutation. As expected from the previous proof-of-concept experiments, the rescuing capacity of human wildtype RAPGEF1 transcript was much higher than that of the mutant one, with the movement parameters recovered to the normal degree (Figure 5 (C) and (D)).
We also observed apparently abnormal spinal motor neuron arborization in the rapgef1a -knockdown zebrafish larvae, either with E2I2-MO or ATG-MO. The motor neuron presented a lower number of axons with incomplete and ectopic sprouts (Figure 5 (E) and (G)). The co-injection of E2I2-MO and human wildtype RAPGEF1 mRNA effectively rescued the phenotype but the co-injection with human mutant RAPGEF1 mRNA failed to do so (Figure 5 (F) and (G)).