Figure 3

HSPC300 is maternally provided and is required in the morphology of embryonic CNS. (a-j) Embryos of indicated genotypes labeled with the axon-specific FasII and BP102 antibodies. All images show a portion of the ventral nerve cord (ventral views, anterior to the top) of stage 16/17 embryos. In wild-type embryos, anti-FasII reveals six longitudinal bundles (a), and BP102 two commissural bundles (b) in each segment. (c,d) HSPC300 embryos show CNS axon morphology that appears wild type. (e-h) Embryos that lack the HSPC300 zygotic component and are maternal hypomorphs show abnormal midline crossing (arrowhead) (e). In the most severe cases (g), axons ectopically cross the midline several times. (f,h) Commissures and longitudinal connectives are not properly formed (arrows). (i,j) Embryos that completely lack zygotic as well as maternal HSPC300 components show strongly disturbed CNS development, broken longitudinal connectives and commissures (asterisks). Scale bar: 20 μm. (k-m) Comparative analysis of HSPC300 expression in embryos of indicated genotypes; ventral views of stage 16 embryos, anterior to the left, anti-HSPC300 labeling. This experiment indicates that HSPC300 is maternally contributed and confirms the specificity of antibody. Scale bar: 50 μm.