FIGURE 4

Phenotypes of dscama, dscamb, and bace2 knockdown zebrafish. Embryos at 5 dpf were stained with HuC/D antibody to observe the intestinal neurons. The neuron numbers in the last six somite lengths of gut were counted. (A) RT-PCR confirmation of splice-blocking morpholino oligonucleotide (SBMO) knockdown in embryos at 48 hpf. In dscama morphants, two small fragments were observed. In dscamb morphants, a shorter fragment was produced, and the amount of PCR products decreased. The length of PCR products from mRNA of bace2 morphants was same as control MO-injected embryos, but the amount of PCR product decreased obviously. (B) qRT-PCR analysis of dscama, dscamb, and bace2 mRNA expression after morpholino injection. The target gene expression levels of SBMO-injected embryos were remarkably reduced compared with the controls. (C–E) Compared with the 0.25 mM control MO injection, 0.25 mM dscama MO injection resulted in a decrease in the density of enteric neurons. (F–H) Embryos injected with 0.125 mM of control MO and 0.125 mM of dscamb MO. (I–K) Embryos injected with 0.375 mM of control MO and 0.25 mM of dscama MO + 0.125 mM of dscamb MO. (L–N) Embryos injected with 0.25 mM of control MO and 0.25 mM of bace2 MO. ^∗∗∗P < 0.001, ^*⁣*⁣**P < 0.0001.