Fig. 7. UNC-119 is required throughout life. (A) Expression of UNC-119 prior to DD axon migration initially rescued the morphology of the DD axons (L1 and L2) relative to non-heat-shocked siblings (-HS). As the animals age, axon morphology declined (AD, adult). unc-119(ed3)mutants carrying the [Phsp::UNC-119] (+HS) constructs were heat shocked prior to DD axon migration (0-5 hours after fertilization). (B) Expression of UNC-119 after axon migration maintained the morphology of the DD neurons. unc-119(ed3) animals carrying the [Phsp::UNC-119] constructs were heat shocked after DD axon migration was completed (10-15 hours after fertilization). (C) Expression of UNC-119 during the L1 larval stage restored axon morphology. unc-119(ed3) carrying the [Phsp::UNC-119] arrays were heat shocked during the L1 larval stage (0-5 hours after hatching). (D) Expression of UNC-119 in the L3 larval stage prevented the decline of axon morphology. unc-119(ed3) animals carrying the [Phsp::UNC-119] arrays were heat shocked in L3 larval stage (36 hours after hatching). The asterisks indicate significant difference compared to the non-heat-shocked controls as determined by an unpaired t-test: *** P<0.0001, ** P< 0.001, *P<0.05.